The artificial photosynthesis technology has been recognized as a promising solution for CO_(2) utilization.Photothermal catalysis has been proposed as a novel strategy to promote the efficiency of artificial photosyn...The artificial photosynthesis technology has been recognized as a promising solution for CO_(2) utilization.Photothermal catalysis has been proposed as a novel strategy to promote the efficiency of artificial photosynthesis by coupling both photochemistry and thermochemistry.However,strategies for maximizing the use of solar spectra with different frequencies in photothermal catalysis are urgently needed.Here,a hierarchical full-spectrum solar light utilization strategy is proposed.Based on this strategy,a Cu@hollow titanium silicalite-1 zeolite(TS-1)nanoreactor with spatially separated photo/thermal catalytic sites is designed to realize high-efficiency photothermal catalytic artificial photosynthesis.The space-time yield of alcohol products over the optimal catalyst reached 64.4μmol g−1 h−1,with the selectivity of CH3CH2OH of 69.5%.This rationally designed hierarchical utilization strategy for solar light can be summarized as follows:(1)high-energy ultraviolet light is utilized to drive the initial and difficult CO_(2) activation step on the TS-1 shell;(2)visible light can induce the localized surface plasmon resonance effect on plasmonic Cu to generate hot electrons for H2O dissociation and subsequent reaction steps;and(3)low-energy near-infrared light is converted into heat by the simulated greenhouse effect by cavities to accelerate the carrier dynamics.This work provides some scientific and experimental bases for research on novel,highly efficient photothermal catalysts for artificial photosynthesis.展开更多
Chinese cabbage(Brassica rapa ssp. pekinensis) has a long cultivation history and is one of the vegetable crops with the largest cultivation area in China. However, salt stress severely damages photosynthesis and horm...Chinese cabbage(Brassica rapa ssp. pekinensis) has a long cultivation history and is one of the vegetable crops with the largest cultivation area in China. However, salt stress severely damages photosynthesis and hormone metabolism, nutritional balances, and results in ion toxicity in plants. To better understand the mechanisms of salt-induced growth inhibition in Chinese cabbage, RNA-seq and physiological index determination were conducted to explore the impacts of salt stress on carbon cycle metabolism and photosynthesis in Chinese cabbage. Here, we found that the number of thylakoids and grana lamellae and the content of starch granules and chlorophyll in the leaves of Chinese cabbage under salt stress showed a time-dependent response, first increasing and then decreasing. Chinese cabbage increased the transcript levels of genes related to the photosynthetic apparatus and carbon metabolism under salt stress, probably in an attempt to alleviate damage to the photosynthetic system and enhance CO_(2) fixation and energy metabolism. The transcription of genes related to starch and sucrose synthesis and degradation were also enhanced;this might have been an attempt to maintain intracellular osmotic pressure by increasing soluble sugar concentrations. Soluble sugars could also be used as potential reactive oxygen species(ROS) scavengers, in concert with peroxidase(POD)enzymes, to eliminate ROS that accumulate during metabolic processes. Our study characterizes the synergistic response network of carbon metabolism and photosynthesis under salt stress.展开更多
Background Light is a critical factor in plant growth and development,particularly in controlled environments.Light-emitting diodes(LEDs)have become a reliable alternative to conventional high pressure sodium(HSP)lamp...Background Light is a critical factor in plant growth and development,particularly in controlled environments.Light-emitting diodes(LEDs)have become a reliable alternative to conventional high pressure sodium(HSP)lamps because they are more efficient and versatile in light sources.In contrast to well-known specialized LED light spectra for vegetables,the appropriate LED lights for crops such as cotton remain unknown.Results In this growth chamber study,we selected and compared four LED lights with varying percentages(26.44%–68.68%)of red light(R,600–700 nm),combined with other lights,for their effects on growth,leaf anatomy,and photosynthesis of cotton seedlings,using HSP lamp as a control.The total photosynthetic photon flux density(PPFD)was(215±2)μmol·m-2·s-1 for all LEDs and HSP lamp.The results showed significant differences in all tested parameters among lights,and the percentage of far red(FR,701–780 nm)within the range of 3.03%–11.86%was positively correlated with plant growth(characterized by leaf number and area,plant height,stem diameter,and total biomass),palisade layer thickness,photosynthesis rate(Pn),and stomatal conductance(Gs).The ratio of R/FR(4.445–11.497)negatively influenced the growth of cotton seedlings,and blue light(B)suppressed stem elongation but increased palisade cell length,chlorophyll content,and Pn.Conclusion The LED 2 was superior to other LED lights and HSP lamp.It had the highest ratio of FR within the total PPFD(11.86%)and the lowest ratio of R/FR(4.445).LED 2 may therefore be used to replace HPS lamp under controlled environments for the study of cotton at the seedling stage.展开更多
This comprehensive review provides a deep exploration of the unique roles of single atom catalysts(SACs)in photocatalytic hydrogen peroxide(H_(2)O_(2))production.SACs offer multiple benefits over traditional catalysts...This comprehensive review provides a deep exploration of the unique roles of single atom catalysts(SACs)in photocatalytic hydrogen peroxide(H_(2)O_(2))production.SACs offer multiple benefits over traditional catalysts such as improved efficiency,selectivity,and flexibility due to their distinct electronic structure and unique properties.The review discusses the critical elements in the design of SACs,including the choice of metal atom,host material,and coordination environment,and how these elements impact the catalytic activity.The role of single atoms in photocatalytic H_(2)O_(2)production is also analysed,focusing on enhancing light absorption and charge generation,improving the migration and separation of charge carriers,and lowering the energy barrier of adsorption and activation of reactants.Despite these advantages,several challenges,including H_(2)O_(2)decomposition,stability of SACs,unclear mechanism,and low selectivity,need to be overcome.Looking towards the future,the review suggests promising research directions such as direct utilization of H_(2)O_(2),high-throughput synthesis and screening,the creation of dual active sites,and employing density functional theory for investigating the mechanisms of SACs in H_(2)O_(2)photosynthesis.This review provides valuable insights into the potential of single atom catalysts for advancing the field of photocatalytic H_(2)O_(2)production.展开更多
Genetic improvement has promoted wheat’s grain yield and nitrogen use efficiency(NUE)during the past decades.Therefore,the current wheat cultivars exhibit higher grain yield and NUE than previous cultivars in the Yan...Genetic improvement has promoted wheat’s grain yield and nitrogen use efficiency(NUE)during the past decades.Therefore,the current wheat cultivars exhibit higher grain yield and NUE than previous cultivars in the Yangtze River Basin,China since the 2000s.However,the critical traits and mechanisms of the increased grain yield and NUE remain unknown.This study explores the mechanisms underlying these new cultivars’increased grain yield and NUE by studying 21 local cultivars cultivated for three growing seasons from 2016 to 2019.Significantly positive correlations were observed between grain yield and NUE in the three years.The cultivars were grouped into high(HH),medium(MM),and low(LL)grain yield and NUE groups.The HH group exhibited significantly high grain yield and NUE.High grain yield was attributed to more effective ears by high tiller fertility and greater single-spike yield by increasing post-anthesis single-stem biomass.Compared to other groups,the HH group demonstrated a longer leaf stay-green ability and a greater flag leaf photosynthetic rate after anthesis.It also showed higher N accumulation at pre-anthesis,which contributed to increasing N accumulation per stem,including stem and leaf sheath,leaf blade,and unit leaf area at pre-anthesis,and promoting N uptake efficiency,the main contribution of high NUE.Moreover,tiller fertility was positively related to N accumulation per stem,N accumulation per unit leaf area,leaf stay-green ability,and flag leaf photosynthetic rate,which indicates that improving tiller fertility promoted N uptake,leaf N accumulation,and photosynthetic ability,thereby achieving synchronous improvements in grain yield and NUE.Therefore,tiller fertility is proposed as an important kernel indicator that can be used in the breeding and management of cultivars to improve agricultural efficiency and sustainability.展开更多
Sugars and auxin have important effects on almost all phases of plant life cycle,which are so fundamental to plants and regulate similar processes.However,little is known about the effect of cross-talk between glucose...Sugars and auxin have important effects on almost all phases of plant life cycle,which are so fundamental to plants and regulate similar processes.However,little is known about the effect of cross-talk between glucose and indole-3-acetic acid(IAA)on growth and development of apple trees.To examine the potential roles of glucose and IAA in root architecture,root nitrogen(N)metabolism and photosynthetic capacity in‘Hanfu’(Malus domestica),a total of five treatments was established:single application of glucose,IAA,and auxin polar transport inhibitor(2,3,5-triiodobenzoic acid,TIBA),combined application of glucose with TIBA and that of glucose with IAA.The combined application of glucose with IAA improved root topology system and endogenous IAA content by altering the mRNA levels of several genes involved in root growth,auxin transport and biosynthesis.Moreover,the increased N metabolism enzyme activities and levels of genes expression related to N in roots may suggest higher rates of transformation of nitrate(NO3--N)into amino acids application of glucose and IAA.Contrarily,single application of TIBA decreased the expression levels of auxin transport gene,hindered root growth and decreased endogenous IAA content.Glucose combined with TIBA application effectively attenuated TIBA-induced reductions in root topology structure,photosynthesis and N metabolism activity,and mRNA expression levels involved in auxin biosynthesis and transport.Taken together,glucose application probably changes the expression level of auxin synthesis and transport genes,and induce the allocation of endogenous IAA in root,and thus improves root architecture and N metabolism of root in soil with deficit carbon.展开更多
Opuntia ficus-indica(L.)Miller is a CAM(crassulacean acid metabolism)plant with an extraordinary capacity to adapt to drought stress by its ability to fix atmospheric CO_(2) at nighttime,store a significant amount of ...Opuntia ficus-indica(L.)Miller is a CAM(crassulacean acid metabolism)plant with an extraordinary capacity to adapt to drought stress by its ability to fix atmospheric CO_(2) at nighttime,store a significant amount of water in cladodes,and reduce root growth.Plants that grow in moisture-stress conditions with thick and less fine root hairs have a strong symbiosis with arbuscular mycorrhizal fungi(AMF)to adapt to drought stress.Water stress can limit plant growth and biomass production,which can be rehabilitated by AMF association through improved physiological performance.The objective of this study was to investigate the effects of AMF inoculations and variable soil water levels on the biomass,photosynthesis,and water use efficiency of the spiny and spineless O.ficus-indica.The experiment was conducted in a greenhouse with a full factorial experiment using O.ficus-indica type(spiny or spineless),AMF(presence or absence),and four soil water available(SWA)treatments through seven replications.Water treatments applied were 0%–25%SWA(T1),25%–50%SWA(T2),50%–75%SWA(T3),and 75%–100%SWA(T4).Drought stress reduced biomass and cladode growth,while AMF colonization significantly increased the biomass production with significant changes in the physiological performance of O.ficus-indica.AMF presence significantly increased biomass of both O.ficus-indica plant types through improved growth,photosynthetic water use efficiency,and photosynthesis.The presence of spines on the surface of cladodes significantly reduced the rate of photosynthesis and photosynthetic water use efficiency.Net photosynthesis,photosynthetic water use efficiency,transpiration,and stomatal conductance rate significantly decreased with increased drought stress.Under drought stress,some planted mother cladodes with the absence of AMF have not established daughter cladodes,whereas AMF-inoculated mother cladodes fully established daughter cladodes.AMF root colonization significantly increased with the decrease of SWA.AMF caused an increase in biomass production,increased tolerance to drought stress,and improved photosynthesis and water use efficiency performance of O.ficus-indica.The potential of O.ficus-indica to adapt to drought stress is controlled by the morpho-physiological performance related to AMF association.展开更多
Reduced photosynthesis results directly from nitrogen or water deficiency in wheat plants,and leads to a decrease in grain yield.In this study,by measuring the effects of water and N deficiencies,both individually and...Reduced photosynthesis results directly from nitrogen or water deficiency in wheat plants,and leads to a decrease in grain yield.In this study,by measuring the effects of water and N deficiencies,both individually and combined,we characterized the responses of wheat(Triticum aestivum L.Yumai 49-198)plants to these two deficiencies using physiological measurements and comparative proteomics.Significant decreases in grain yield and leaf photosynthetic performance were observed in all deficiency conditions,and 106 photosynthetic proteins that showed responses were identified.Nitrogen deficiency induced the least change in photosynthetic proteins,and similar changes in most of these proteins were also observed for the combined nitrogen and water deficiencies.Water deficiency induced the largest change in photosynthetic proteins and resulted in the lowest 1000-kernel weight.Severe decreases in photosynthesis in both the water-deficiency and combined N and water deficiency groups were reflected mainly in an imbalanced ATP/NADPH ratio associated with the light reaction,which influences carbon metabolism in the Calvin cycle.Photorespiration was respectively stimulated or inhibited by N or water deficiency,while suppression of photorespiratory flux and activation of nitrogen recycling were observed in the combined N and water deficiency treatments.Comparison of photosynthetic proteins between experimental sites suggested that precipitation affected linear electron flow in the photoreaction,and thus photosynthetic efficiency.Our results provide a baseline for future studies of the roles of these photosynthetic proteins in the response to N or water deficiency and their effect on 1000-kernel weight.展开更多
Elevating soil water content(SWC)through irrigation was one of the simple mitigation measures to improve crop resilience to heat stress.The response of leaf function,such as photosynthetic capacity based on chlorophyl...Elevating soil water content(SWC)through irrigation was one of the simple mitigation measures to improve crop resilience to heat stress.The response of leaf function,such as photosynthetic capacity based on chlorophyll fluorescence during the mitigation,has received limited attention,especially in field conditions.A two-year field experiment with three treatments(control treatment(CK),high-temperature treatment(H),and high-temperature together with elevating SWC treatment(HW))was carried out during grain filling with two maize hybrids at a typical station in North China Plain.Averagely,the net photosynthetic rate(Pn)was improved by 20%,and the canopy temperature decreased by 1–3℃ in HW compared with in H in both years.Furthermore,the higher SWC in HW significantly improved the actual photosynthetic rate(Phi2),linear electron flow(LEF),variable fluorescence(F_(v)),and the maximal potential quantum efficiency(F_(v)/F_(m))for both hybrids.Meanwhile,different responses in chlorophyll fluorescence between hybrids were also observed.The higher SWC in HW significantly improved thylakoid proton conductivity(g H^(+))and the maximal fluorescence(F_(m))for the hybrid ZD958.For the hybrid XY335,the proton conductivity of chloroplast ATP synthase(v H^(+))and the minimal fluorescence(Fo)was increased by the SWC.The structural equation model(SEM)further showed that SWC had significantly positive relationships with Pn,LEF,and F_(v)/F_(m).The elevating SWC alleviated heat stress with the delayed leaf senescence to prolong the effective period of photosynthesis and enhanced leaf photosynthetic capacity by improving Phi2,LEF,Fv,and F_(v)/F_(m).This research demonstrates that elevating SWC through enhancing leaf photosynthesis during grain filling would be an important mitigation strategy for adapting to the warming climate in maize production.展开更多
The low-efficiency CO_(2) uptake capacity and insufficient photogenerated exciton dissociation of current metal halide perovskite(MHP)nanocrystals with end-capping ligands extremely restrict their application in the f...The low-efficiency CO_(2) uptake capacity and insufficient photogenerated exciton dissociation of current metal halide perovskite(MHP)nanocrystals with end-capping ligands extremely restrict their application in the field of artificial photosynthesis.Herein,we demonstrate that ligand-free CsPbBr_(3) with calliandralike nanostructure(LF-CPB CL)can be synthesized easily through a ligand-free seed-assisted dissolutionrecrystallization growth process,exhibiting significantly enhanced CO_(2) uptake capacity.More specifically,the abundant surface bromine(Br)vacancies in ligand-free MHP materials are demonstrated to be beneficial to photogenerated carrier separation.The electron consumption rate of LF-CPB CL for photocatalytic CO_(2) reduction increases 7 and 20 times over those of traditional ligand-capping CsPbBr_(3)nanocrystal(L-CPB NC)and bulk CsPbBr_(3),respectively.Moreover,the absence of ligand hindrance can facilitate the interfacial electronic coupling between LF-CPB CL and tetra(4-carboxyphenyl)porphyrin iron(Ⅲ)chloride(Fe-TCPP)cocatalyst,bringing forth significantly accelerated interfacial charge separation.The LF-CPB CL/Fe-TCPP exhibits a total electron consumption rate of 145.6μmol g^(-1) h^(-1) for CO_(2)photoreduction coupled with water oxidation which is over 14 times higher than that of L-CPB NC/FeTCPP.展开更多
Photosynthesis affects crop growth and yield.The roles of microRNAs(miRNAs)in photosynthesis are little known.In the present study,the role of the OsNF-YB7–OsMIR5810–OsMRLP6 regulatory module in photosynthesis was i...Photosynthesis affects crop growth and yield.The roles of microRNAs(miRNAs)in photosynthesis are little known.In the present study,the role of the OsNF-YB7–OsMIR5810–OsMRLP6 regulatory module in photosynthesis was investigated.The malectin-like protein gene OsMRLP6 was identified as a target gene of osa-miR5810(miR5810).Overexpression in rice of miR5810 or down-expression of OsMRLP6 resulted in reduced expression of genes involved in chloroplast development and photosynthesis and decreased net photosynthetic rate,finally leading to lower shoot biomass and grain yield.Down-expression of miR5810 and overexpression of OsMRLP6 showed the opposite effect.Overexpression of transcription factor OsNF-YB7 elevated expression of OsMIR5810 in rice seedlings by binding to its promoter.The OsNFYB7–OsMIR5810–OsMRLP6 regulatory module affects photosynthesis to mediate growth and grain yield.展开更多
Background Mepiquat chloride(MC)application and plant population density(PPD)increasing are required for modern cotton production.However,their interactive effects on leaf physiology and carbohydrate metabolism remain...Background Mepiquat chloride(MC)application and plant population density(PPD)increasing are required for modern cotton production.However,their interactive effects on leaf physiology and carbohydrate metabolism remain obscure.This study aimed to examine whether and how MC and PPD affect the leaf morpho-physiological characteristics,and thus final cotton yield.PPD of three levels(D1:2.25 plants·m^(-2),D2:4.5 plants·m^(-2),and D3:6.75 plants·m^(-2))and MC dosage of two levels(MC0:0 g·ha^(-2),MC1:82.5 g·ha^(-2))were combined to create six treatments.The dynamics of nonstructual carbohydrate concentration,carbon metabolism-related enzyme activity,and photosynthetic attributes in cotton leaves were examined during reproductive growth in 2019 and 2020.Results Among six treatments,the high PPD of 6.75 plants·m^(-2)combined with MC application(MC1D3)exhibited the greatest seed cotton yield and biological yield.The sucrose,hexose,starch,and total nonstructural carbohydrate(TNC)concentrations peaked at the first flowering(FF)stage and then declined to a minimum at the first boll opening(FBO)stage.Compared with other treatments,MC1D3 improved starch and TNC concentration by 5.4%~88.4%,7.8%~52.0% in 2019,and by 14.6%~55.9%,13.5%~39.7% in 2020 at the FF stage,respectively.Additionally,MC1D3 produced higher transformation rates of starch and TNC from the FF to FBO stages,indicating greater carbon production and utilization efficiency.MC1D3 displayed the maximal specific leaf weight(SLW)at the FBO stage,and the highest chlorophyll a(Chl a),Chl b,and Chl a+b concentration at the mid-late growth phase in both years.The Rubisco activity with MC1D3 was 2.6%~53.2% higher at the flowering and boll setting stages in both years,and 2.4%~52.7% higher at the FBO stage in 2020 than those in other treatments.These results provided a explanation of higher leaf senescence-resistant ability in MC1D3.Conclusion Increasing PPD coupled with MC application improves cotton yield by enhancing leaf carbohydrate production and utilization efficiency and delaying leaf senescence.展开更多
A challenge for the development of Land Surface Models(LSMs) is improving transpiration of water exchange and photosynthesis of carbon exchange between terrestrial plants and the atmosphere, both of which are governed...A challenge for the development of Land Surface Models(LSMs) is improving transpiration of water exchange and photosynthesis of carbon exchange between terrestrial plants and the atmosphere, both of which are governed by stoma in leaves. In the photosynthesis module of these LSMs, variations of parameters arising from diversity in plant functional types(PFTs) and climate remain unclear. Identifying sensitive parameters among all photosynthetic parameters before parameter estimation can not only reduce operation cost, but also improve the usability of photosynthesis models worldwide. Here, we analyzed 13 parameters of a biochemically-based photosynthesis model(FvCB), implemented in many LSMs, using two sensitivity analysis(SA) methods(i.e., the Sobol’ method and the Morris method) for setting up the parameter ensemble. Three different model performance metrics, i.e.,Root Mean Squared Error(RMSE), Nash Sutcliffe efficiency(NSE), and Standard Deviation(STDEV) were introduced for model assessment and sensitive parameters identification. The results showed that among all photosynthetic parameters only a small portion of parameters were sensitive, and the sensitive parameters were different across plant functional types: maximum rate of Rubisco activity(Vcmax25), maximum electron transport rate(Jmax25), triose phosphate use rate(TPU) and dark respiration in light(Rd) were sensitive in broad leafevergreen trees(BET), broad leaf-deciduous trees(BDT) and needle leaf-evergreen trees(NET), while only Vcmax25and TPU are sensitive in short vegetation(SV), dwarf trees and shrubs(DTS), and agriculture and grassland(AG). The two sensitivity analysis methods suggested a strong SA coherence;in contrast, different model performance metrics led to different SA results. This misfit suggests that more accurate values of sensitive parameters, specifically, species specific and seasonal variable parameters, are required to improve the performance of the FvCB model.展开更多
Improvement of photosynthetic efficiency is a major approach to increase crop yield potential.Previously,we cloned a gene encoding the chloroplast-located putative monooxygenase TCD5,which is essential in plastid deve...Improvement of photosynthetic efficiency is a major approach to increase crop yield potential.Previously,we cloned a gene encoding the chloroplast-located putative monooxygenase TCD5,which is essential in plastid development under low temperature in rice(Oryza sativa L.).In this study,the effects of TCD5 on the photosynthesis and the yields were investigated in rice.Two sets of genetic materials with three levels of TCD5 expression,including tcd5 mutant or TCD5 RNAi transgenic lines and TCD5 over-expression transgenic lines in Jiahua1 and Nipponbare backgrounds,were used in the field trails of multi-locations and multi-years.TCD5 positively affected the panicle number and the yield at dosage.Compared with the wild-types,the panicle numbers were 12.4%-14.6%less in tcd5 mutant and 8.3%-38.6%less in TCD5 RNAi lines,but 26.2%-61.8%more in TCD5 over-expression lines.The grain yields per plant were 9.1%-18.4%less in tcd5 mutant and 14.3%-56.7%less in TCD5 RNAi lines,but 6.9%-56.5%more in TCD5 over-expression lines.The measurements of net photosynthetic rate indicated that mutation or knock down of TCD5 decreased the net photosynthetic rate by 10.4%and 15.6%,respectively,while increasing it by 8.9%and 8.7%in the TCD5 over-expression lines in Jiahua1 and Nipponbare backgrounds,respectively.Accordingly,the measurements of chlorophyll fluorescence parameters showed that the electron transport rate and quantum yield decreased in tcd5 mutant or TCD5 RNAi lines but increased in TCD5 overexpression lines,both in Jiahua1 and Nipponbare backgrounds.IP-MS screening revealed that TCD5 interacts with 29 chloroplast proteins involved in chlorophyll synthesis,photo-reactions of the photosynthesis,carbon assimilation and metabolism,energy metabolism,redox balance,protein synthesis and transportation.Two TCD5 interacted proteins,D1 and FBA were effective targets for improving photosynthesis.These results suggest a potentially new strategy for increasing rice yield by enhancing photosynthesis.展开更多
Dwarf Water Lilies Nymphoides aquatica(J.F.Gmel)Kuntze have floating and submerged leaves.Some submerged aquatic vascular plants have a form of CAM(Crassulacean Acid Metabolism)called Submerged Aquatic Macrophyte(SAM)...Dwarf Water Lilies Nymphoides aquatica(J.F.Gmel)Kuntze have floating and submerged leaves.Some submerged aquatic vascular plants have a form of CAM(Crassulacean Acid Metabolism)called Submerged Aquatic Macrophyte(SAM)metabolism.Blue-diode based PAM technology was used to measure the Photosynthetic Oxygen Evolution Rate(POER:1O_(2)≡4e^(-)).Optimum Irradiance(E_(opt)),maximum POER(POER_(max))and quantum efficiency(α_(0))all vary on a diurnal cycle.The shape of the POER vs.E curves is different in seedling,submerged and surface leaves.Both E_(opt) and POER_(max) are very low in seedling leaves(E_(opt)≈104μmol photon m^(-2) s^(-1),PPFD;POER_(max)≈4.95µmol O_(2) g^(-1) Chl a s^(-1)),intermediate in mature submerged leaves(E_(opt)≈419µmol photon m^(-2) s^(-1) PPFD,POER_(max)≈38.1µmol O_(2) g^(-1) Chl a s^(-1))and very high in surface leaves(E_(opt)≈923µmol photon m^(-2) s^(-1) PPFD,POER_(max)≈76.1µmol O_(2) g^(-1) Chl a s^(-1)).Leaf titratable acid(C4 acid pool)is too small(≈20 to 50 mol H+m^(-3))to support substantial SAM metabolism.Gross daily photosynthesis of surface leaves is≈3.71 g C m^(-2) d^(-1) in full sun and as much as 1.4 gC m^(-2) d^(-1) in shaded submerged leaves.There is midday inhibition of photosynthesis.展开更多
Nitrogen(N)is a critical element for plant growth and productivity that influences photosynthesis and chlorophyll fluorescence.We investigated the effect of low-N stress on leaf photosynthesis and chlorophyll fluoresc...Nitrogen(N)is a critical element for plant growth and productivity that influences photosynthesis and chlorophyll fluorescence.We investigated the effect of low-N stress on leaf photosynthesis and chlorophyll fluorescence characteristics of maize cultivars with difference in tolerance to low N levels.The low-N tolerant cultivar ZH311 and low-N sensitive cultivar XY508 were used as the test materials.A field experiment(with three N levels:N0,0 kg ha–1;N1,150 kg ha–1;N2,300 kg ha–1)in Jiyanyang,Sichuan Province,China,and a hydroponic experiment(with two N levels:CK,4 mmol L–1;LN,0.04 mmol L–1)in Chengdu,Sichuan Province,China were conducted.Low-N stress significantly decreased chlorophyll content and rapid light response curves of the maximum fluorescence under light(Fm′),fluorescence instable state(Fs),non-photochemical quenching(qN),the maximum efficiency of PSII photochemistry under dark-adaption(Fv/Fm),potential activity of PSII(Fv/Fo),and actual photochemical efficiency of PSII(ΦPSII)of leaves.Further,it increased the chlorophyll(Chl)a/Chl b values and so on.The light compensation point of ZH311 decreased,while that of XY508 increased.The degree of variation of these indices in low-N tolerant cultivars was lower than that in low-N sensitive cultivars,especially at the seedling stage.Maize could increase Chl a/Chl b,apparent quantum yield and light saturation point to adapt to N stress.Compared to low-N sensitive cultivars,low-N tolerant cultivars maintained a higher net photosynthetic rate and electron transport rate to maintain stronger PSII activity,which further promoted the ability to harvest and transfer light.This might be a photosynthetic mechanism by which low-N tolerant cultivar adapt to low-N stress.展开更多
To understand the contribution of ear photosynthesis to grain yield and its response to water supply in the improvement of winter wheat, 15 cultivars released from 1980 to 2012 in North China Plain(NCP) were planted u...To understand the contribution of ear photosynthesis to grain yield and its response to water supply in the improvement of winter wheat, 15 cultivars released from 1980 to 2012 in North China Plain(NCP) were planted under rainfed and irrigated conditions from 2011 to 2013, and the ear photosynthesis was tested by ear shading. During the past 30 years, grain yield significantly increased, the flag leaf area slightly increased under irrigated condition but decreased significantly under rainfed condition, the ratio of grain weight:leaf area significantly increased, and the contribution of ear photosynthesis to grain yield changed from 33.6 to 64.5% and from 32.2 to 57.2% under rainfed and irrigated conditions, respectively. Grain yield, yield components, and ratio of grain weight:leaf area were positively related with contribution of ear photosynthesis. The increase in grain yield in winter wheat was related with improvement in ear photosynthesis contribution in NCP, especially under rainfed condition.展开更多
As the most northerly mangrove species in China, Kandelia obovata may undergo extreme cold event stress. Enhancing the cold tolerance of this species is crucial to its successful afforestation. This study aimed to det...As the most northerly mangrove species in China, Kandelia obovata may undergo extreme cold event stress. Enhancing the cold tolerance of this species is crucial to its successful afforestation. This study aimed to determine the resistance of K. obovata seedlings to low temperature stress by cold acclimation and to explain the mechanisms for alleviating cold injury. To understand these mechanisms, seedlings that were acclimatized and not acclimatized were exposed to 5℃/- 2℃(day/night)for 48 h.Results showed that low temperature stress reduced leaf photosynthesis of non-acclimatized seedlings by inducing oxidative stress and structural damage to chloroplasts. These phenomena were shown by increasing levels of malondialdehyde (MDA), O2-and H2O2, as well as decreasing enzyme activities in the ascorbate–glutathione (AsA-GSH) cycle. However, cold-acclimatized seedlings had improved photosynthetic rates and efficiency of photosystem II (PSII) under low temperature stress. Compared with non-acclimatized seedlings, leaves of coldacclimatized seedlings under low temperature stress for 48 h exhibited higher anti-oxidative enzyme activities, lower levels of O2^- and H2O2, less damage to chloroplast structure, and removed 33.7% of MDA at low temperature stress for 48 h. The data indicate that cold acclimation enhances photosynthetic capacity by effectively regulating activation in the PSII electron transport and the AsA–GSH cycle to scavenge excess ROS in chloroplasts, while the latter is more important.展开更多
Potassium(K)deficiency significantly decreases photosynthesis due to leaf chlorosis induced by accumulation of reactive oxygen species(ROS).But,the physiological mechanism for adjusting antioxidative defense system to...Potassium(K)deficiency significantly decreases photosynthesis due to leaf chlorosis induced by accumulation of reactive oxygen species(ROS).But,the physiological mechanism for adjusting antioxidative defense system to protect leaf function in maize(Zea mays L.)is unknown.In the present study,four maize inbred lines(K-tolerant,90-21-3 and 099;K-sensitive,D937 and 835)were used to analyze leaf photosynthesis,anatomical structure,chloroplast ultrastructure,ROS,and antioxidant activities.The results showed that the chlorophyll content,net photosynthetic rate(P_n),stomatal conductance(G_s),photochemical quenching(q_P),and electron transport rate of PSII(ETR)in 90-21-3 and 099 were higher than those in D937 and 835 under K deficiency treatment.Parameters of leaf anatomical structure in D937 that were significantly changed under K deficiency treatment include smaller thickness of leaf,lower epidermis cells,and vascular bundle area,whereas the vascular bundle area,xylem vessel number,and area in 90-21-3 were significantly larger or higher.D937 also had seriously damaged chloroplasts and PSII reaction centers along with increased superoxide anion(O_2^-·)and hydrogen peroxide(H_2O_2).Activities of antioxidants,like superoxide dismutase(SOD),catalase(CAT),and ascorbate peroxidase(APX),were significantly stimulated in 90-21-3 resulting in lower levels of O_2^-·and H_2O_2.These results indicated that the K-tolerant maize promoted antioxidant enzyme activities to maintain ROS homeostasis and suffered less oxidative damage on the photosynthetic apparatus,thereby maintaining regular photosynthesis under K deficiency stress.展开更多
Maize-specific pyruvate orthophosphate dikinase(PPDK) was overexpressed in rice independently or in combination with the maize C4-specific phosphoenolpyruvate carboxylase(PCK). The wild-type(WT) cultivar Kitaake and t...Maize-specific pyruvate orthophosphate dikinase(PPDK) was overexpressed in rice independently or in combination with the maize C4-specific phosphoenolpyruvate carboxylase(PCK). The wild-type(WT) cultivar Kitaake and transgenic plants were evaluated in independent field and tank experiments. Three soil moisture treatments,well-watered(WW), moderate drought(MD) and severe drought(SD), were imposed from 9d post-anthesis till maturity. Leaf physiological and biochemical traits, root activities,biomass, grain yield, and yield components in the untransformed WT and two transgenic rice lines(PPDK and PCK) were systematically studied. Compared with the WT, both transgenic rice lines showed increased leaf photosynthetic rate: by 20%–40% under WW, by45%–60% under MD, and by 80%–120% under SD. The transgenic plants produced 16.1%,20.2% and 20.0% higher grain yields than WT under the WW, MD and SD treatments,respectively. Under the same soil moisture treatments, activities of phosphoenolpyruvate carboxylase(PEPC) and carbonic anhydrase(CA) in transgenic plants were 3–5-fold higher than those in WT plants. Compared with ribulose-1,5-bisphosphate carboxylase, activities of PEPC and CA were less reduced under both MD and SD treatments. The transgenic plants also showed higher leaf water content, stomatal conductance, transpiration efficiency, and root oxidation activity and a stronger active oxygen scavenging system than the WT under all soil moisture treatments, especially MD and SD. The results suggest that drought tolerance is greatly enhanced in transgenic rice plants overexpressing C4photosynthesis enzymes. This study was performed under natural conditions and normal planting density to evaluate yield advantages on a field basis. It may open a new avenue to droughttolerance breeding via overexpression of C4enzymes in rice.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.21908052 and 22108200)the Key Program of the Natural Science Foundation of Hebei Province(Grant No.B2020209017)+2 种基金the Project of Science and Technology Innovation Team,Tangshan(Grant No.20130203D)the Natural Science Foundation of Zhejiang Province(Grant No.LQ22B060013)and the Science and Technology Project of Hebei Education Department(Grant No.QN2021113).
文摘The artificial photosynthesis technology has been recognized as a promising solution for CO_(2) utilization.Photothermal catalysis has been proposed as a novel strategy to promote the efficiency of artificial photosynthesis by coupling both photochemistry and thermochemistry.However,strategies for maximizing the use of solar spectra with different frequencies in photothermal catalysis are urgently needed.Here,a hierarchical full-spectrum solar light utilization strategy is proposed.Based on this strategy,a Cu@hollow titanium silicalite-1 zeolite(TS-1)nanoreactor with spatially separated photo/thermal catalytic sites is designed to realize high-efficiency photothermal catalytic artificial photosynthesis.The space-time yield of alcohol products over the optimal catalyst reached 64.4μmol g−1 h−1,with the selectivity of CH3CH2OH of 69.5%.This rationally designed hierarchical utilization strategy for solar light can be summarized as follows:(1)high-energy ultraviolet light is utilized to drive the initial and difficult CO_(2) activation step on the TS-1 shell;(2)visible light can induce the localized surface plasmon resonance effect on plasmonic Cu to generate hot electrons for H2O dissociation and subsequent reaction steps;and(3)low-energy near-infrared light is converted into heat by the simulated greenhouse effect by cavities to accelerate the carrier dynamics.This work provides some scientific and experimental bases for research on novel,highly efficient photothermal catalysts for artificial photosynthesis.
基金financially supported by the Natural Science Foundation of Hebei Province-Innovation Group Research Project(Grant No.C2020204111)the National Natural Science Foundation of China(Grant No.31930098)+3 种基金the Science Fund for Distinguished Young Scholars of Hebei Province(Grant No.C2021204049)the Hebei Province Outstanding Youth Fund(Grant No.BJ2021024)the Hebei Provincial Key Research Projects(21326344D)Hebei International Joint Research Base of Modern Agricultural Biotechnology.
文摘Chinese cabbage(Brassica rapa ssp. pekinensis) has a long cultivation history and is one of the vegetable crops with the largest cultivation area in China. However, salt stress severely damages photosynthesis and hormone metabolism, nutritional balances, and results in ion toxicity in plants. To better understand the mechanisms of salt-induced growth inhibition in Chinese cabbage, RNA-seq and physiological index determination were conducted to explore the impacts of salt stress on carbon cycle metabolism and photosynthesis in Chinese cabbage. Here, we found that the number of thylakoids and grana lamellae and the content of starch granules and chlorophyll in the leaves of Chinese cabbage under salt stress showed a time-dependent response, first increasing and then decreasing. Chinese cabbage increased the transcript levels of genes related to the photosynthetic apparatus and carbon metabolism under salt stress, probably in an attempt to alleviate damage to the photosynthetic system and enhance CO_(2) fixation and energy metabolism. The transcription of genes related to starch and sucrose synthesis and degradation were also enhanced;this might have been an attempt to maintain intracellular osmotic pressure by increasing soluble sugar concentrations. Soluble sugars could also be used as potential reactive oxygen species(ROS) scavengers, in concert with peroxidase(POD)enzymes, to eliminate ROS that accumulate during metabolic processes. Our study characterizes the synergistic response network of carbon metabolism and photosynthesis under salt stress.
基金funded by the China Agriculture Research System(CARS-15-16).
文摘Background Light is a critical factor in plant growth and development,particularly in controlled environments.Light-emitting diodes(LEDs)have become a reliable alternative to conventional high pressure sodium(HSP)lamps because they are more efficient and versatile in light sources.In contrast to well-known specialized LED light spectra for vegetables,the appropriate LED lights for crops such as cotton remain unknown.Results In this growth chamber study,we selected and compared four LED lights with varying percentages(26.44%–68.68%)of red light(R,600–700 nm),combined with other lights,for their effects on growth,leaf anatomy,and photosynthesis of cotton seedlings,using HSP lamp as a control.The total photosynthetic photon flux density(PPFD)was(215±2)μmol·m-2·s-1 for all LEDs and HSP lamp.The results showed significant differences in all tested parameters among lights,and the percentage of far red(FR,701–780 nm)within the range of 3.03%–11.86%was positively correlated with plant growth(characterized by leaf number and area,plant height,stem diameter,and total biomass),palisade layer thickness,photosynthesis rate(Pn),and stomatal conductance(Gs).The ratio of R/FR(4.445–11.497)negatively influenced the growth of cotton seedlings,and blue light(B)suppressed stem elongation but increased palisade cell length,chlorophyll content,and Pn.Conclusion The LED 2 was superior to other LED lights and HSP lamp.It had the highest ratio of FR within the total PPFD(11.86%)and the lowest ratio of R/FR(4.445).LED 2 may therefore be used to replace HPS lamp under controlled environments for the study of cotton at the seedling stage.
基金This work was financially supported by the Guangdong Basic and Applied Basic Research Foundation(2020A1515010982)the National Natural Science Foundation of China(21805191)+2 种基金Shenzhen Science and Technology Program(JCYJ20210324094000001,20190808142001745,20200812122947002)Shenzhen Peacock Plan(20210802524B and 20180921273B)the Australian Research Council(FT200100015)。
文摘This comprehensive review provides a deep exploration of the unique roles of single atom catalysts(SACs)in photocatalytic hydrogen peroxide(H_(2)O_(2))production.SACs offer multiple benefits over traditional catalysts such as improved efficiency,selectivity,and flexibility due to their distinct electronic structure and unique properties.The review discusses the critical elements in the design of SACs,including the choice of metal atom,host material,and coordination environment,and how these elements impact the catalytic activity.The role of single atoms in photocatalytic H_(2)O_(2)production is also analysed,focusing on enhancing light absorption and charge generation,improving the migration and separation of charge carriers,and lowering the energy barrier of adsorption and activation of reactants.Despite these advantages,several challenges,including H_(2)O_(2)decomposition,stability of SACs,unclear mechanism,and low selectivity,need to be overcome.Looking towards the future,the review suggests promising research directions such as direct utilization of H_(2)O_(2),high-throughput synthesis and screening,the creation of dual active sites,and employing density functional theory for investigating the mechanisms of SACs in H_(2)O_(2)photosynthesis.This review provides valuable insights into the potential of single atom catalysts for advancing the field of photocatalytic H_(2)O_(2)production.
基金supported by the National Natural Science Foundation of China(31771711 and 32071953)the National Key Research and Development Program of China(2016YFD0300405)+1 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutions,China,the Project of the Vice General Manager of Science and Technology of Jiangsu Province,China(FZ20211472)the Plan of Gathering 1000 Leading Talents of Suqian,China.
文摘Genetic improvement has promoted wheat’s grain yield and nitrogen use efficiency(NUE)during the past decades.Therefore,the current wheat cultivars exhibit higher grain yield and NUE than previous cultivars in the Yangtze River Basin,China since the 2000s.However,the critical traits and mechanisms of the increased grain yield and NUE remain unknown.This study explores the mechanisms underlying these new cultivars’increased grain yield and NUE by studying 21 local cultivars cultivated for three growing seasons from 2016 to 2019.Significantly positive correlations were observed between grain yield and NUE in the three years.The cultivars were grouped into high(HH),medium(MM),and low(LL)grain yield and NUE groups.The HH group exhibited significantly high grain yield and NUE.High grain yield was attributed to more effective ears by high tiller fertility and greater single-spike yield by increasing post-anthesis single-stem biomass.Compared to other groups,the HH group demonstrated a longer leaf stay-green ability and a greater flag leaf photosynthetic rate after anthesis.It also showed higher N accumulation at pre-anthesis,which contributed to increasing N accumulation per stem,including stem and leaf sheath,leaf blade,and unit leaf area at pre-anthesis,and promoting N uptake efficiency,the main contribution of high NUE.Moreover,tiller fertility was positively related to N accumulation per stem,N accumulation per unit leaf area,leaf stay-green ability,and flag leaf photosynthetic rate,which indicates that improving tiller fertility promoted N uptake,leaf N accumulation,and photosynthetic ability,thereby achieving synchronous improvements in grain yield and NUE.Therefore,tiller fertility is proposed as an important kernel indicator that can be used in the breeding and management of cultivars to improve agricultural efficiency and sustainability.
基金supported by the National Key Research and Development Program of China(Grant No.2020YFD1000201)National Natural Science Foundation(Grant No.31972359)+1 种基金Earmarked Fund for CARS(Grant No.CARS-27)Agricultural Research and Industrialization Project of Liaoning Province(Grant No.2020JH2/10200028).
文摘Sugars and auxin have important effects on almost all phases of plant life cycle,which are so fundamental to plants and regulate similar processes.However,little is known about the effect of cross-talk between glucose and indole-3-acetic acid(IAA)on growth and development of apple trees.To examine the potential roles of glucose and IAA in root architecture,root nitrogen(N)metabolism and photosynthetic capacity in‘Hanfu’(Malus domestica),a total of five treatments was established:single application of glucose,IAA,and auxin polar transport inhibitor(2,3,5-triiodobenzoic acid,TIBA),combined application of glucose with TIBA and that of glucose with IAA.The combined application of glucose with IAA improved root topology system and endogenous IAA content by altering the mRNA levels of several genes involved in root growth,auxin transport and biosynthesis.Moreover,the increased N metabolism enzyme activities and levels of genes expression related to N in roots may suggest higher rates of transformation of nitrate(NO3--N)into amino acids application of glucose and IAA.Contrarily,single application of TIBA decreased the expression levels of auxin transport gene,hindered root growth and decreased endogenous IAA content.Glucose combined with TIBA application effectively attenuated TIBA-induced reductions in root topology structure,photosynthesis and N metabolism activity,and mRNA expression levels involved in auxin biosynthesis and transport.Taken together,glucose application probably changes the expression level of auxin synthesis and transport genes,and induce the allocation of endogenous IAA in root,and thus improves root architecture and N metabolism of root in soil with deficit carbon.
基金supported by the Ethiopian Ministry of Education.
文摘Opuntia ficus-indica(L.)Miller is a CAM(crassulacean acid metabolism)plant with an extraordinary capacity to adapt to drought stress by its ability to fix atmospheric CO_(2) at nighttime,store a significant amount of water in cladodes,and reduce root growth.Plants that grow in moisture-stress conditions with thick and less fine root hairs have a strong symbiosis with arbuscular mycorrhizal fungi(AMF)to adapt to drought stress.Water stress can limit plant growth and biomass production,which can be rehabilitated by AMF association through improved physiological performance.The objective of this study was to investigate the effects of AMF inoculations and variable soil water levels on the biomass,photosynthesis,and water use efficiency of the spiny and spineless O.ficus-indica.The experiment was conducted in a greenhouse with a full factorial experiment using O.ficus-indica type(spiny or spineless),AMF(presence or absence),and four soil water available(SWA)treatments through seven replications.Water treatments applied were 0%–25%SWA(T1),25%–50%SWA(T2),50%–75%SWA(T3),and 75%–100%SWA(T4).Drought stress reduced biomass and cladode growth,while AMF colonization significantly increased the biomass production with significant changes in the physiological performance of O.ficus-indica.AMF presence significantly increased biomass of both O.ficus-indica plant types through improved growth,photosynthetic water use efficiency,and photosynthesis.The presence of spines on the surface of cladodes significantly reduced the rate of photosynthesis and photosynthetic water use efficiency.Net photosynthesis,photosynthetic water use efficiency,transpiration,and stomatal conductance rate significantly decreased with increased drought stress.Under drought stress,some planted mother cladodes with the absence of AMF have not established daughter cladodes,whereas AMF-inoculated mother cladodes fully established daughter cladodes.AMF root colonization significantly increased with the decrease of SWA.AMF caused an increase in biomass production,increased tolerance to drought stress,and improved photosynthesis and water use efficiency performance of O.ficus-indica.The potential of O.ficus-indica to adapt to drought stress is controlled by the morpho-physiological performance related to AMF association.
基金supported by the National Key Research and Development Program of China(2018YFD0300707 and 2016YFD0300105)the Modern Wheat Industrial Technology System of Henan Province(S2010-01-G07).
文摘Reduced photosynthesis results directly from nitrogen or water deficiency in wheat plants,and leads to a decrease in grain yield.In this study,by measuring the effects of water and N deficiencies,both individually and combined,we characterized the responses of wheat(Triticum aestivum L.Yumai 49-198)plants to these two deficiencies using physiological measurements and comparative proteomics.Significant decreases in grain yield and leaf photosynthetic performance were observed in all deficiency conditions,and 106 photosynthetic proteins that showed responses were identified.Nitrogen deficiency induced the least change in photosynthetic proteins,and similar changes in most of these proteins were also observed for the combined nitrogen and water deficiencies.Water deficiency induced the largest change in photosynthetic proteins and resulted in the lowest 1000-kernel weight.Severe decreases in photosynthesis in both the water-deficiency and combined N and water deficiency groups were reflected mainly in an imbalanced ATP/NADPH ratio associated with the light reaction,which influences carbon metabolism in the Calvin cycle.Photorespiration was respectively stimulated or inhibited by N or water deficiency,while suppression of photorespiratory flux and activation of nitrogen recycling were observed in the combined N and water deficiency treatments.Comparison of photosynthetic proteins between experimental sites suggested that precipitation affected linear electron flow in the photoreaction,and thus photosynthetic efficiency.Our results provide a baseline for future studies of the roles of these photosynthetic proteins in the response to N or water deficiency and their effect on 1000-kernel weight.
基金supported by the Key R&D Program Project in Hebei Province,China(22326408D)the 2115 Talent Development Program of China Agricultural University。
文摘Elevating soil water content(SWC)through irrigation was one of the simple mitigation measures to improve crop resilience to heat stress.The response of leaf function,such as photosynthetic capacity based on chlorophyll fluorescence during the mitigation,has received limited attention,especially in field conditions.A two-year field experiment with three treatments(control treatment(CK),high-temperature treatment(H),and high-temperature together with elevating SWC treatment(HW))was carried out during grain filling with two maize hybrids at a typical station in North China Plain.Averagely,the net photosynthetic rate(Pn)was improved by 20%,and the canopy temperature decreased by 1–3℃ in HW compared with in H in both years.Furthermore,the higher SWC in HW significantly improved the actual photosynthetic rate(Phi2),linear electron flow(LEF),variable fluorescence(F_(v)),and the maximal potential quantum efficiency(F_(v)/F_(m))for both hybrids.Meanwhile,different responses in chlorophyll fluorescence between hybrids were also observed.The higher SWC in HW significantly improved thylakoid proton conductivity(g H^(+))and the maximal fluorescence(F_(m))for the hybrid ZD958.For the hybrid XY335,the proton conductivity of chloroplast ATP synthase(v H^(+))and the minimal fluorescence(Fo)was increased by the SWC.The structural equation model(SEM)further showed that SWC had significantly positive relationships with Pn,LEF,and F_(v)/F_(m).The elevating SWC alleviated heat stress with the delayed leaf senescence to prolong the effective period of photosynthesis and enhanced leaf photosynthetic capacity by improving Phi2,LEF,Fv,and F_(v)/F_(m).This research demonstrates that elevating SWC through enhancing leaf photosynthesis during grain filling would be an important mitigation strategy for adapting to the warming climate in maize production.
基金financially supported by the Natural Science Foundation of Tianjin City(17JCJQJC43800)the National Key R&D Program of China(2017YFA0700104)+1 种基金the National Science Foundation of China(21931007,U21A20286)Jiangsu Funding Program for Excellent Postdoctoral Talent and the 111 Project of China(D17003)。
文摘The low-efficiency CO_(2) uptake capacity and insufficient photogenerated exciton dissociation of current metal halide perovskite(MHP)nanocrystals with end-capping ligands extremely restrict their application in the field of artificial photosynthesis.Herein,we demonstrate that ligand-free CsPbBr_(3) with calliandralike nanostructure(LF-CPB CL)can be synthesized easily through a ligand-free seed-assisted dissolutionrecrystallization growth process,exhibiting significantly enhanced CO_(2) uptake capacity.More specifically,the abundant surface bromine(Br)vacancies in ligand-free MHP materials are demonstrated to be beneficial to photogenerated carrier separation.The electron consumption rate of LF-CPB CL for photocatalytic CO_(2) reduction increases 7 and 20 times over those of traditional ligand-capping CsPbBr_(3)nanocrystal(L-CPB NC)and bulk CsPbBr_(3),respectively.Moreover,the absence of ligand hindrance can facilitate the interfacial electronic coupling between LF-CPB CL and tetra(4-carboxyphenyl)porphyrin iron(Ⅲ)chloride(Fe-TCPP)cocatalyst,bringing forth significantly accelerated interfacial charge separation.The LF-CPB CL/Fe-TCPP exhibits a total electron consumption rate of 145.6μmol g^(-1) h^(-1) for CO_(2)photoreduction coupled with water oxidation which is over 14 times higher than that of L-CPB NC/FeTCPP.
基金We thank Dr.Baixiao Niu(Yangzhou University)for providing YB7-ox transgenic rice plants.the Guangzhou Science and Technology Project(202102021003,2023B03J0742)the National Natural Science Foundation of China(32171933).
文摘Photosynthesis affects crop growth and yield.The roles of microRNAs(miRNAs)in photosynthesis are little known.In the present study,the role of the OsNF-YB7–OsMIR5810–OsMRLP6 regulatory module in photosynthesis was investigated.The malectin-like protein gene OsMRLP6 was identified as a target gene of osa-miR5810(miR5810).Overexpression in rice of miR5810 or down-expression of OsMRLP6 resulted in reduced expression of genes involved in chloroplast development and photosynthesis and decreased net photosynthetic rate,finally leading to lower shoot biomass and grain yield.Down-expression of miR5810 and overexpression of OsMRLP6 showed the opposite effect.Overexpression of transcription factor OsNF-YB7 elevated expression of OsMIR5810 in rice seedlings by binding to its promoter.The OsNFYB7–OsMIR5810–OsMRLP6 regulatory module affects photosynthesis to mediate growth and grain yield.
基金supported by the National Natural Science Foundation of China(grant no.31960385)the Natural Science Foundation of Jiangxi,China(grant no.20212BAB215009)。
文摘Background Mepiquat chloride(MC)application and plant population density(PPD)increasing are required for modern cotton production.However,their interactive effects on leaf physiology and carbohydrate metabolism remain obscure.This study aimed to examine whether and how MC and PPD affect the leaf morpho-physiological characteristics,and thus final cotton yield.PPD of three levels(D1:2.25 plants·m^(-2),D2:4.5 plants·m^(-2),and D3:6.75 plants·m^(-2))and MC dosage of two levels(MC0:0 g·ha^(-2),MC1:82.5 g·ha^(-2))were combined to create six treatments.The dynamics of nonstructual carbohydrate concentration,carbon metabolism-related enzyme activity,and photosynthetic attributes in cotton leaves were examined during reproductive growth in 2019 and 2020.Results Among six treatments,the high PPD of 6.75 plants·m^(-2)combined with MC application(MC1D3)exhibited the greatest seed cotton yield and biological yield.The sucrose,hexose,starch,and total nonstructural carbohydrate(TNC)concentrations peaked at the first flowering(FF)stage and then declined to a minimum at the first boll opening(FBO)stage.Compared with other treatments,MC1D3 improved starch and TNC concentration by 5.4%~88.4%,7.8%~52.0% in 2019,and by 14.6%~55.9%,13.5%~39.7% in 2020 at the FF stage,respectively.Additionally,MC1D3 produced higher transformation rates of starch and TNC from the FF to FBO stages,indicating greater carbon production and utilization efficiency.MC1D3 displayed the maximal specific leaf weight(SLW)at the FBO stage,and the highest chlorophyll a(Chl a),Chl b,and Chl a+b concentration at the mid-late growth phase in both years.The Rubisco activity with MC1D3 was 2.6%~53.2% higher at the flowering and boll setting stages in both years,and 2.4%~52.7% higher at the FBO stage in 2020 than those in other treatments.These results provided a explanation of higher leaf senescence-resistant ability in MC1D3.Conclusion Increasing PPD coupled with MC application improves cotton yield by enhancing leaf carbohydrate production and utilization efficiency and delaying leaf senescence.
基金supported by the CAS"Light of West China"Program (No.[2020]82)Key technology projects of Inner Mongolia Autonomous Region (Grant No.2020GG0306)+1 种基金Science and Technology Plan Projects of Alxa League (Grant No.AMY2020-18)Natural Science Foundation of Gansu Province (No.21JR7RA038).
文摘A challenge for the development of Land Surface Models(LSMs) is improving transpiration of water exchange and photosynthesis of carbon exchange between terrestrial plants and the atmosphere, both of which are governed by stoma in leaves. In the photosynthesis module of these LSMs, variations of parameters arising from diversity in plant functional types(PFTs) and climate remain unclear. Identifying sensitive parameters among all photosynthetic parameters before parameter estimation can not only reduce operation cost, but also improve the usability of photosynthesis models worldwide. Here, we analyzed 13 parameters of a biochemically-based photosynthesis model(FvCB), implemented in many LSMs, using two sensitivity analysis(SA) methods(i.e., the Sobol’ method and the Morris method) for setting up the parameter ensemble. Three different model performance metrics, i.e.,Root Mean Squared Error(RMSE), Nash Sutcliffe efficiency(NSE), and Standard Deviation(STDEV) were introduced for model assessment and sensitive parameters identification. The results showed that among all photosynthetic parameters only a small portion of parameters were sensitive, and the sensitive parameters were different across plant functional types: maximum rate of Rubisco activity(Vcmax25), maximum electron transport rate(Jmax25), triose phosphate use rate(TPU) and dark respiration in light(Rd) were sensitive in broad leafevergreen trees(BET), broad leaf-deciduous trees(BDT) and needle leaf-evergreen trees(NET), while only Vcmax25and TPU are sensitive in short vegetation(SV), dwarf trees and shrubs(DTS), and agriculture and grassland(AG). The two sensitivity analysis methods suggested a strong SA coherence;in contrast, different model performance metrics led to different SA results. This misfit suggests that more accurate values of sensitive parameters, specifically, species specific and seasonal variable parameters, are required to improve the performance of the FvCB model.
基金funded by the National Natural Science Foundation of China(Grand No.U19A2025)Scientific Research Foundation of China Jiliang University.
文摘Improvement of photosynthetic efficiency is a major approach to increase crop yield potential.Previously,we cloned a gene encoding the chloroplast-located putative monooxygenase TCD5,which is essential in plastid development under low temperature in rice(Oryza sativa L.).In this study,the effects of TCD5 on the photosynthesis and the yields were investigated in rice.Two sets of genetic materials with three levels of TCD5 expression,including tcd5 mutant or TCD5 RNAi transgenic lines and TCD5 over-expression transgenic lines in Jiahua1 and Nipponbare backgrounds,were used in the field trails of multi-locations and multi-years.TCD5 positively affected the panicle number and the yield at dosage.Compared with the wild-types,the panicle numbers were 12.4%-14.6%less in tcd5 mutant and 8.3%-38.6%less in TCD5 RNAi lines,but 26.2%-61.8%more in TCD5 over-expression lines.The grain yields per plant were 9.1%-18.4%less in tcd5 mutant and 14.3%-56.7%less in TCD5 RNAi lines,but 6.9%-56.5%more in TCD5 over-expression lines.The measurements of net photosynthetic rate indicated that mutation or knock down of TCD5 decreased the net photosynthetic rate by 10.4%and 15.6%,respectively,while increasing it by 8.9%and 8.7%in the TCD5 over-expression lines in Jiahua1 and Nipponbare backgrounds,respectively.Accordingly,the measurements of chlorophyll fluorescence parameters showed that the electron transport rate and quantum yield decreased in tcd5 mutant or TCD5 RNAi lines but increased in TCD5 overexpression lines,both in Jiahua1 and Nipponbare backgrounds.IP-MS screening revealed that TCD5 interacts with 29 chloroplast proteins involved in chlorophyll synthesis,photo-reactions of the photosynthesis,carbon assimilation and metabolism,energy metabolism,redox balance,protein synthesis and transportation.Two TCD5 interacted proteins,D1 and FBA were effective targets for improving photosynthesis.These results suggest a potentially new strategy for increasing rice yield by enhancing photosynthesis.
文摘Dwarf Water Lilies Nymphoides aquatica(J.F.Gmel)Kuntze have floating and submerged leaves.Some submerged aquatic vascular plants have a form of CAM(Crassulacean Acid Metabolism)called Submerged Aquatic Macrophyte(SAM)metabolism.Blue-diode based PAM technology was used to measure the Photosynthetic Oxygen Evolution Rate(POER:1O_(2)≡4e^(-)).Optimum Irradiance(E_(opt)),maximum POER(POER_(max))and quantum efficiency(α_(0))all vary on a diurnal cycle.The shape of the POER vs.E curves is different in seedling,submerged and surface leaves.Both E_(opt) and POER_(max) are very low in seedling leaves(E_(opt)≈104μmol photon m^(-2) s^(-1),PPFD;POER_(max)≈4.95µmol O_(2) g^(-1) Chl a s^(-1)),intermediate in mature submerged leaves(E_(opt)≈419µmol photon m^(-2) s^(-1) PPFD,POER_(max)≈38.1µmol O_(2) g^(-1) Chl a s^(-1))and very high in surface leaves(E_(opt)≈923µmol photon m^(-2) s^(-1) PPFD,POER_(max)≈76.1µmol O_(2) g^(-1) Chl a s^(-1)).Leaf titratable acid(C4 acid pool)is too small(≈20 to 50 mol H+m^(-3))to support substantial SAM metabolism.Gross daily photosynthesis of surface leaves is≈3.71 g C m^(-2) d^(-1) in full sun and as much as 1.4 gC m^(-2) d^(-1) in shaded submerged leaves.There is midday inhibition of photosynthesis.
基金financially supported by the Sichuan Key Technology Support Program of China (2014NZ0040)the Special Fund for Agro-scientific Research in the Public Interest of China (20150312705)
文摘Nitrogen(N)is a critical element for plant growth and productivity that influences photosynthesis and chlorophyll fluorescence.We investigated the effect of low-N stress on leaf photosynthesis and chlorophyll fluorescence characteristics of maize cultivars with difference in tolerance to low N levels.The low-N tolerant cultivar ZH311 and low-N sensitive cultivar XY508 were used as the test materials.A field experiment(with three N levels:N0,0 kg ha–1;N1,150 kg ha–1;N2,300 kg ha–1)in Jiyanyang,Sichuan Province,China,and a hydroponic experiment(with two N levels:CK,4 mmol L–1;LN,0.04 mmol L–1)in Chengdu,Sichuan Province,China were conducted.Low-N stress significantly decreased chlorophyll content and rapid light response curves of the maximum fluorescence under light(Fm′),fluorescence instable state(Fs),non-photochemical quenching(qN),the maximum efficiency of PSII photochemistry under dark-adaption(Fv/Fm),potential activity of PSII(Fv/Fo),and actual photochemical efficiency of PSII(ΦPSII)of leaves.Further,it increased the chlorophyll(Chl)a/Chl b values and so on.The light compensation point of ZH311 decreased,while that of XY508 increased.The degree of variation of these indices in low-N tolerant cultivars was lower than that in low-N sensitive cultivars,especially at the seedling stage.Maize could increase Chl a/Chl b,apparent quantum yield and light saturation point to adapt to N stress.Compared to low-N sensitive cultivars,low-N tolerant cultivars maintained a higher net photosynthetic rate and electron transport rate to maintain stronger PSII activity,which further promoted the ability to harvest and transfer light.This might be a photosynthetic mechanism by which low-N tolerant cultivar adapt to low-N stress.
基金supported by the National Natural Science Foundation of China (31401297)the National Key Research and Development Program of China (2016YFD0300105)+1 种基金the Chinese Universities Scientific Fund (2016NX002)the Earmarked Fund for Modern Agro-Industry Technology Research System, China (CARS-3)
文摘To understand the contribution of ear photosynthesis to grain yield and its response to water supply in the improvement of winter wheat, 15 cultivars released from 1980 to 2012 in North China Plain(NCP) were planted under rainfed and irrigated conditions from 2011 to 2013, and the ear photosynthesis was tested by ear shading. During the past 30 years, grain yield significantly increased, the flag leaf area slightly increased under irrigated condition but decreased significantly under rainfed condition, the ratio of grain weight:leaf area significantly increased, and the contribution of ear photosynthesis to grain yield changed from 33.6 to 64.5% and from 32.2 to 57.2% under rainfed and irrigated conditions, respectively. Grain yield, yield components, and ratio of grain weight:leaf area were positively related with contribution of ear photosynthesis. The increase in grain yield in winter wheat was related with improvement in ear photosynthesis contribution in NCP, especially under rainfed condition.
基金supported by Zhejiang Provincial Natural Science Foundation of China(Grant Nos.LY18C030001 and LQ13C030002)National Natural Science Foundation of China(Grant No.41776097)+4 种基金Special Funding for Research of National Oceanic Public Service Industry of China(Grant No.201505028)National Science and Technology Basic Resources Survey Special of China(Grant No.2017FY100700)Zhejiang Province Science and Technology Plan Project of China(Grant Nos.2013C25096 and2014F50003)Zhejiang Province Foundation of the Nonprofit Technology Research Projects of China(Grant No.2015C33227)Wenzhou Municipal Science and Technology Plan Project of China(Grant Nos.N20140046,N20170008 and S20160004)
文摘As the most northerly mangrove species in China, Kandelia obovata may undergo extreme cold event stress. Enhancing the cold tolerance of this species is crucial to its successful afforestation. This study aimed to determine the resistance of K. obovata seedlings to low temperature stress by cold acclimation and to explain the mechanisms for alleviating cold injury. To understand these mechanisms, seedlings that were acclimatized and not acclimatized were exposed to 5℃/- 2℃(day/night)for 48 h.Results showed that low temperature stress reduced leaf photosynthesis of non-acclimatized seedlings by inducing oxidative stress and structural damage to chloroplasts. These phenomena were shown by increasing levels of malondialdehyde (MDA), O2-and H2O2, as well as decreasing enzyme activities in the ascorbate–glutathione (AsA-GSH) cycle. However, cold-acclimatized seedlings had improved photosynthetic rates and efficiency of photosystem II (PSII) under low temperature stress. Compared with non-acclimatized seedlings, leaves of coldacclimatized seedlings under low temperature stress for 48 h exhibited higher anti-oxidative enzyme activities, lower levels of O2^- and H2O2, less damage to chloroplast structure, and removed 33.7% of MDA at low temperature stress for 48 h. The data indicate that cold acclimation enhances photosynthetic capacity by effectively regulating activation in the PSII electron transport and the AsA–GSH cycle to scavenge excess ROS in chloroplasts, while the latter is more important.
基金supported by the National Natural Science Foundation of China (31771725 and 31301259)the National Key Technology R&D Program of China (2013BAD07B03)
文摘Potassium(K)deficiency significantly decreases photosynthesis due to leaf chlorosis induced by accumulation of reactive oxygen species(ROS).But,the physiological mechanism for adjusting antioxidative defense system to protect leaf function in maize(Zea mays L.)is unknown.In the present study,four maize inbred lines(K-tolerant,90-21-3 and 099;K-sensitive,D937 and 835)were used to analyze leaf photosynthesis,anatomical structure,chloroplast ultrastructure,ROS,and antioxidant activities.The results showed that the chlorophyll content,net photosynthetic rate(P_n),stomatal conductance(G_s),photochemical quenching(q_P),and electron transport rate of PSII(ETR)in 90-21-3 and 099 were higher than those in D937 and 835 under K deficiency treatment.Parameters of leaf anatomical structure in D937 that were significantly changed under K deficiency treatment include smaller thickness of leaf,lower epidermis cells,and vascular bundle area,whereas the vascular bundle area,xylem vessel number,and area in 90-21-3 were significantly larger or higher.D937 also had seriously damaged chloroplasts and PSII reaction centers along with increased superoxide anion(O_2^-·)and hydrogen peroxide(H_2O_2).Activities of antioxidants,like superoxide dismutase(SOD),catalase(CAT),and ascorbate peroxidase(APX),were significantly stimulated in 90-21-3 resulting in lower levels of O_2^-·and H_2O_2.These results indicated that the K-tolerant maize promoted antioxidant enzyme activities to maintain ROS homeostasis and suffered less oxidative damage on the photosynthetic apparatus,thereby maintaining regular photosynthesis under K deficiency stress.
基金the National Basic Research Program (973 Program, 2012CB114306)the National Natural Science Foundation of China (31061140457+6 种基金 31071360 31271641)the National Key Technology Support Program of China (2011BAD16B14 2012BAD04B08)China National Public Welfare Industry (Agriculture) Plan (200803030 201203079)Jiangsu Advantages of Key Construction Projects (JS 2011)
文摘Maize-specific pyruvate orthophosphate dikinase(PPDK) was overexpressed in rice independently or in combination with the maize C4-specific phosphoenolpyruvate carboxylase(PCK). The wild-type(WT) cultivar Kitaake and transgenic plants were evaluated in independent field and tank experiments. Three soil moisture treatments,well-watered(WW), moderate drought(MD) and severe drought(SD), were imposed from 9d post-anthesis till maturity. Leaf physiological and biochemical traits, root activities,biomass, grain yield, and yield components in the untransformed WT and two transgenic rice lines(PPDK and PCK) were systematically studied. Compared with the WT, both transgenic rice lines showed increased leaf photosynthetic rate: by 20%–40% under WW, by45%–60% under MD, and by 80%–120% under SD. The transgenic plants produced 16.1%,20.2% and 20.0% higher grain yields than WT under the WW, MD and SD treatments,respectively. Under the same soil moisture treatments, activities of phosphoenolpyruvate carboxylase(PEPC) and carbonic anhydrase(CA) in transgenic plants were 3–5-fold higher than those in WT plants. Compared with ribulose-1,5-bisphosphate carboxylase, activities of PEPC and CA were less reduced under both MD and SD treatments. The transgenic plants also showed higher leaf water content, stomatal conductance, transpiration efficiency, and root oxidation activity and a stronger active oxygen scavenging system than the WT under all soil moisture treatments, especially MD and SD. The results suggest that drought tolerance is greatly enhanced in transgenic rice plants overexpressing C4photosynthesis enzymes. This study was performed under natural conditions and normal planting density to evaluate yield advantages on a field basis. It may open a new avenue to droughttolerance breeding via overexpression of C4enzymes in rice.
