Abiotic stresses, such as drought, salt, extreme temperatures, and heavy metal pollution, are the main environmental factors that limit crop growth and yield. Sorghum, a C4 grass plant with high photosynthetic efficie...Abiotic stresses, such as drought, salt, extreme temperatures, and heavy metal pollution, are the main environmental factors that limit crop growth and yield. Sorghum, a C4 grass plant with high photosynthetic efficiency, can grow in adverse environmental conditions due to its excellent stress resistance characteristics. Therefore, unraveling the stress-resistance mechanism of sorghum could provide a theoretical basis for developing and cultivating various stress-resistant crops. This understanding could also help to create a conducive environment for using marginal soil in agriculture and ensuring food security. In this review, we discuss the adaptation mechanisms of sorghum under drought, salinity, temperature, and soil heavy metal stresses, the specific response to stress, the screening of sorghum-resistant germplasm, and the identification and functional analysis of the relevant genes and quantitative trait loci(QTL). In addition, we discuss the application potential of different stress-tolerant sorghum germplasms reported to date and emphasize the feasibility and potential use in developing and promoting highly stress-tolerant sorghum in marginal soil.展开更多
The G protein-coupled receptor(GPCR)regulates downstream genes by binding to a heterotrimeric G protein.However,the function of sex peptide receptor(SPR)in lepidopteran species is mostly unknown.Understanding the phys...The G protein-coupled receptor(GPCR)regulates downstream genes by binding to a heterotrimeric G protein.However,the function of sex peptide receptor(SPR)in lepidopteran species is mostly unknown.Understanding the physiological functions of SPR in insects is essential for exploring new insecticidal targets.In the present study,the functions of an SPR in Lymantria dispar(Asian gypsy moth;LdSPR)were investigated.The expression of LdSPR was the highest in the 6 th instar larval stage,and there was a large difference in expression between male and female adults.After LdSPR gene silencing,L.dispar larvae showed increased sensitivity to high temperature,starvation,and oxidative stress,indicating that LdSPR enhances stress resistance.These results enrich our knowledge of the function of the insect SPRs,which will lead to a better understanding of other insect GPCR family members and the identification of new targets for the development of environmentally friendly pesticides.展开更多
Rapeseed is the largest source of China's edible vegetable oil and plays a pivotal role in China's edible oil market.With global warming and frequent occurrence of various extreme climates,traditional hybrid b...Rapeseed is the largest source of China's edible vegetable oil and plays a pivotal role in China's edible oil market.With global warming and frequent occurrence of various extreme climates,traditional hybrid breeding has been unable to meet the production requirements for rape yield and stress resistance.In recent years,the rapid development and maturity of molecular marker technologies have opened up new ways for stress resistance breeding in rape.This article mainly discusses several types of molecular marker technologies commonly used in rapeseed breeding,such as RFLP,SSR,and SNP,the advantages of molecular marker technologies over conventional breeding and other genetic marker technologies,as well as the application of molecular marker technologies in rapeseed disease resistance,drought resistance,cold resistance and lodging resistance breeding,the current problems and development prospects in breeding.展开更多
Sophora moorcroftiana(S. moorcroftiana) is an endemic leguminous dwarf shrub in Tibet, China. Decoctions of the seeds have been used in Chinese folk medicine for dephlogistication, detoxication, and infectious disease...Sophora moorcroftiana(S. moorcroftiana) is an endemic leguminous dwarf shrub in Tibet, China. Decoctions of the seeds have been used in Chinese folk medicine for dephlogistication, detoxication, and infectious diseases. The present study aimed to investigate the constituent and biological effects of polysaccharides from S. moorcroftiana seeds in Caenorhabditis elegans(C. elegans). Polysaccharides from S. moorcroftiana seeds(SMpol) were extracted with 60% ethanol and constituent was analyzed by GC-MS. SMpol was composed of glucose, galactose and inositol in the molar ratio of 35.7 : 1.3 : 17.0. Synchronized worms were treated with SMpol and then lifespan, motility, reproduction, stress resistance and antimicrobial activity were examined. Compared with the control group, the lifespan was increased to the average of 27.3 days and the number of laying eggs showed a 1.3-fold increase in nematodes treated with SMpol(4 mg×mL^(–1)). In SMpol(4 mg×mL^(–1)) treated worms, there was a 1.1-fold increase in 24-h survival of acute heat stress and a 1.6-fold increase in 2-h survival of oxidative stress The colonization of the bacteria in the SMpol treated nematode was significantly lower than that of the untreated group by 68.3%. In vivo studies showed SMpol significantly extended the life span, improved reproduction, increased stress resistance and antimicrobial capacity of C. elegans. In conclusion, those results indicated that the polysaccharides from S. moorcroftiana seeds were involved in a variety of biological activities leading to its modulatory effects on C. elegans which may be developed as a natural supplement agent.展开更多
Bacteria inhabit diverse and dynamic environments,where nutrients may be limited and toxic chemicals can be prevalent.To adapt to these stressful conditions,bacteria have evolved specialized protein secretion systems,...Bacteria inhabit diverse and dynamic environments,where nutrients may be limited and toxic chemicals can be prevalent.To adapt to these stressful conditions,bacteria have evolved specialized protein secretion systems,such as the type VI secretion system(T6SS)to facilitate their survival.As a molecular syringe,the T6SS expels various effectors into neighboring bacterial cells,eukaryotic cells,or the extracellular environment.These effectors improve the competitive fitness and environmental adaption of bacterial cells.Although primarily recognized as antibacterial weapons,recent studies have demonstrated that T6SSs have functions beyond interspecies competition.Here,we summarize recent research on the role of T6SSs in microbiome modulation,pathogenesis,and stress resistance.展开更多
[Objectives]To study the germplasm resources of excellent peach cultivars.[Methods]Five peach cultivars were introduced,in-cluding‘Jinxiu’peach,‘Jinxiang’peach,‘Chunxiao’peach,‘Hujingmilu’peach and‘018 nectar...[Objectives]To study the germplasm resources of excellent peach cultivars.[Methods]Five peach cultivars were introduced,in-cluding‘Jinxiu’peach,‘Jinxiang’peach,‘Chunxiao’peach,‘Hujingmilu’peach and‘018 nectarine’peach.Then,these five cultivars were used to study the biological characteristics of peach trees,namely,as phenology,fruit quality,heat resistance,cold resistance and other resistance.[Results]Five cultivars of peach plants grew fast and robust,among which‘018 nectarine’had very crisp fruit,‘Jinxiu’,‘Jinxiang’,‘Chunxiao’and‘Hujingmilu’had very sweet fruitꎻthe peach trees of these five cultivars have good water resistance,heat resist-ance and cold resistance.[Conclusions]The results of this study can not only provide a reference for the introduction of peach trees,but also provide a practical basis for the large-scale planting of peach trees.展开更多
Lonicera japonica Thunb.is widely distributed in China.It has strong adaptability to the environment and can maintain normal growth and development under a variety of stress conditions.It is commonly used as a medicin...Lonicera japonica Thunb.is widely distributed in China.It has strong adaptability to the environment and can maintain normal growth and development under a variety of stress conditions.It is commonly used as a medicine with its dry flower buds or newly opened flowers,named honeysuckle,and with both economic value and ecological application value.The research progress of L.japonica Thunb.under stress conditions such as temperature,drought,light,salt,heavy metals and diseases,pests and endophytic bacteria was reviewed,and the current research situation of the physiological and biochemical response mechanism,changes of photosynthetic fluorescence and accumulation of secondary metabolites of honeysuckle under different stresses was discussed,so as to provide a reference for deep-level exploring the resistance mechanism of L.japonica Thunb.in the future and lay a theoretical foundation for the high-quality authentic ecological cultivation of L.japonica Thunb.展开更多
[Objectives]This study was conducted to clarify the saline-alkali tolerance in seedlings of Lonicera caerulea L.[Methods]The L.caerulea seedling variety,Lanjingling,was used as the test material,and alkaline solution(...[Objectives]This study was conducted to clarify the saline-alkali tolerance in seedlings of Lonicera caerulea L.[Methods]The L.caerulea seedling variety,Lanjingling,was used as the test material,and alkaline solution(NaHCO 3)with different concentration gradients was used for stress treatment to observe physiological effects on L.caerulea seedlings.[Results]L.caerulea seedlings were most affected by alkaline stress at a treatment concentration of 100 mmol/L,and their osmotic substances(proline,soluble sugar,soluble protein)and antioxidant enzymes(CAT,SOD and POD)were higher in content at a concentration of 100 mmol/L compared with the alkaline stresses in this range.The contents were generally higher,and even in the detection of proline,soluble sugar,SOD and POD,the contents of these substances and enzymes reached a peak at 100 mmol/L.The contents of soluble sugar,CAT,SOD,POD and malondialdehyde were generally higher than that of the control check(CK),and the contents of proline and soluble protein in each treatment concentration were generally higher than that of the CK.[Conclusions]The metabolic physiology of L.caerulea seedlings has a certain adaptability to alkaline stress.展开更多
Hypoxic preconditioning is able to increase the body’s resistance to hypoxic/ischemic stress. Understanding how to apply the hypoxic response to initiate the protective mechanism of ischemic preconditioning is a high...Hypoxic preconditioning is able to increase the body’s resistance to hypoxic/ischemic stress. Understanding how to apply the hypoxic response to initiate the protective mechanism of ischemic preconditioning is a high priority. However, the relationship between innate resistance to hypoxic stress and preconditioning efficiency of moderate hypoxia has been poorly studied. In our work, the efficiency of single moderate hypobaric hypoxia (HBH) for resistance to severe hypobaric hypoxia (SHBH) was studied on intact rats and those pre-tested under SHBH with low, intermediate and high resistance to hypoxia. HBH has a significant preconditioning action on the resistance to hypoxia over a wide range from 270 to 1464 s (4.5 to 24.5 min) and at the same time eliminates the differences in the endurance under SHBH between all rat groups. It is concluded that 1) HBH preconditioning efficiency does not depend on an innate resistance to SHBH and prior hypoxic experience of rats;and 2) the pretesting to severe hypoxia has no value for predicting the hypoxic preconditioning efficiency and study of adaptive mechanisms.展开更多
Lignans are a powerful weapon for plants to resist stresses and have diverse bioactive functions to protect human health.Elucidating the mechanisms of stereoselective biosynthesis and response to stresses of lignans i...Lignans are a powerful weapon for plants to resist stresses and have diverse bioactive functions to protect human health.Elucidating the mechanisms of stereoselective biosynthesis and response to stresses of lignans is important for the guidance of plant improvement.Here,we identified the complete pathway to stereoselectively synthesize antiviral(-)-lariciresinol glucosides in Isatis indigotica roots,which consists of three-step sequential stereoselective enzymes DIR1/2,PLR,and UGT71B2.DIR1 was further identified as the key gene in respoJanuary 2024nse to stresses and was able to trigger stress defenses by mediating the elevation in lignan content.Mechanistically,the phytohormone-responsive ERF transcription factor LTF1 colocalized with DIR1 in the cell periphery of the vascular regions in mature roots and helped resist biotic and abiotic stresses by directly regulating the expression of DIR1.These systematic results suggest that DIR1 as the first common step of the lignan pathway cooperates with PLR and UGT71B2 to stereoselectively synthesize(-)-lariciresinol derived antiviral lignans in I.indigotica roots and is also a part of the LTF1-mediated regulatory network to resist stresses.In conclusion,the LTF1-DIR1 module is an ideal engineering target to improve plant Defenses while increasing the content of valuable lignans in plants.展开更多
[Objectives]To study the adaptability of introduced pear.[Methods]Five pear varieties,"Aidang"pear,"Taiwan Zaomi"pear,"Cuiguan"pear,"Tianjin Yali"pear and"Zaosheng Xinshui&...[Objectives]To study the adaptability of introduced pear.[Methods]Five pear varieties,"Aidang"pear,"Taiwan Zaomi"pear,"Cuiguan"pear,"Tianjin Yali"pear and"Zaosheng Xinshui"pear,were introduced.Then,using these five varieties,the phenology of pear trees,various characters of fruit,stress resistance(heat tolerance and cold tolerance)of varieties were studied.[Results]The plants of 5 varieties of pear trees grew fast and were robust;in late March,it went into the flowering period;"Aidang"pear fruit had a certain number of stone cells;"Taiwan Zaomi"pear had the highest sweetness;"Cuiguan"pear had the largest fruit;these five varieties of pear trees had good water resistance,heat resistance and cold resistance.[Conclusions]This study can provide a reference for the introduction of pear trees,and can also provide a practical basis for the large-scale planting of pear trees.展开更多
[Objectives]To study the introduction performance of pomegranate(Punica granatum)varieties in Shanghai area.[Methods]In this experiment,five pomegranate varieties were introduced,namely‘American 002’pomegranate,‘Hu...[Objectives]To study the introduction performance of pomegranate(Punica granatum)varieties in Shanghai area.[Methods]In this experiment,five pomegranate varieties were introduced,namely‘American 002’pomegranate,‘Huohulu’pomegranate,‘Wanli No.1’pomegranate,‘Yicheng Hongpitian’pomegranate,and‘American Qingpisuan’pomegranate.Then,using these five varieties,various biological traits such as phenology and fruit quality of pomegranate,as well as stress resistance such as heat resistance and cold resistance were studied.[Results]Five varieties of pomegranates began to mature in succession in early September;the smallest single fruit weight was 90 g,and the largest was 110 g;the plants grew fast,the plants were strong,the flowers were single petal,and plants bore fruits which were ornamental and edible.In addition,the pomegranates of these five varieties had good water tolerance and heat resistance,and good cold resistance.[Conclusions]This study is intended to provide a certain reference for the introduction of pomegranate varieties,and also provide a practical basis for the large-scale planting of pomegranate.展开更多
Objective: To investigate the effects of Andrographis paniculata(Burm.f.) Wall. Ex Nees(A. paniculata) on expressions and activities of catalase, superoxide dismutase and alkylhydroperoxide reductase C in Staphylococc...Objective: To investigate the effects of Andrographis paniculata(Burm.f.) Wall. Ex Nees(A. paniculata) on expressions and activities of catalase, superoxide dismutase and alkylhydroperoxide reductase C in Staphylococcus aureus(S. aureus) with respect to its survival in vitro. Methods: Antioxidative property of methanolic leaves extract of A. paniculata(0.06 mg/m L). Minimum inhibitory concentration(MIC) was determined by its ability to reduce hydrogen peroxide(H_2O_2) toxicity against S. aureus ATCC 25923(3.8×10~8 cfu/m L). Effects of the extract on expressions of kat A(encoding catalase), sod A and sod M [encoding superoxide dismutases(SODs)], and ahp C [encoding alkylhydroperoxide reductase C(AhpC)] in S. aureuswere determined by RT-q PCR and corresponding enzyme activity assays were performed. Nitroblue tetrazolium reduction(NBT) assay was performed to determine effects of the extract on intracellular and extracellular levels of O_2-in S. aureus. Results: Cells challenged with 7.5 mmol/L H_2O_2 showed 0% survival in 30 min whereas 25% survived after treatment with the extract and H_2O_2. Cells that were treated with the extract alone had 43% survival in the same exposure period. Expressions of sod A and sod M genes in extract-treated cells were lowered 0.8-fold and 0.7-fold, respectively with decrease in total SOD activity of 26.8 U compared to untreated cells, 32.4 U(P<0.05). In contrast, extract-treated S. aureus cells showed 3.3-fold increase in kat A expression with corresponding increase in catalase activity of 1.828 U compared to untreated cells which was 1.248 U,(P<0.05). More profoundly, ahp C expression was increased 61-fold in extract-treated cells,(P<0.05) with corresponding increase in Ahp C activity of 0.018 U compared to untreated cells, 0.012U,(P<0.05). Extract-treated cells had significantly lower intra-and extracellular O_2-levels with absorbance readings(A_(575nm)) of 0.340 and 0.524 compared to untreated cells which were 0.516 and 0.928(P<0.05), respectively. Conclusions: Taken together these results suggest that the low MIC of A. paniculatamethanolic leaves extract(0.06 mg/m L) reduce H_2O_2 toxicity and more importantly, was in itself effectively inhibitory against S. aureus. Further, our observations suggest that a probable mode of its inhibitory mechanism against S. aureus is by reducing total SOD activity through downregulation of sod A and sod M expressions.展开更多
Alkali stress is a major constraint for crop production in many regions of saline-alkali land.However,little is known about the mechanisms through which wheat responds to alkali stress.In this study,we identified a ca...Alkali stress is a major constraint for crop production in many regions of saline-alkali land.However,little is known about the mechanisms through which wheat responds to alkali stress.In this study,we identified a calcium ion-binding protein from wheat,TaCCD1,which is critical for regulating the plasma membrane(PM)H^(+)-ATPase-mediated alkali stress response.PM H+-ATPase activity is closely related to alkali tolerance in the wheat variety Shanrong 4(SR4).We found that two D-clade type 2C protein phosphatases,TaPP2C.D1 and TaPP2C.D8(TaPP2C.D1/8),negatively modulate alkali stress tolerance by dephosphorylating the penultimate threonine residue(Thr926)of TaHA2 and thereby inhibiting PM H+-ATPase activity.Alkali stress induces the expression of TaCCD1 in SR4,and TaCCD1 interacts with TaSAUR215,an early auxin-responsive protein.These responses are both dependent on calcium signaling triggered by alkali stress.TaCCD1 enhances the inhibitory effect of TaSAUR215 on TaPP2C.D1/8 activity,thereby promoting the activity of the PM H^(+)-ATPase TaHA2 and alkali stress tolerance in wheat.Functional and genetic analyses verified the effects of these genes in response to alkali stress,indicating that TaPP2C.D1/8 function downstream of TaSAUR215 and TaCCD1.Collectively,this study uncovers a new signaling pathway that regulates wheat responses to alkali stress,in which Ca^(2+)-dependent TaCCD1 cooperates with TaSAUR215 to enhance PM H+-ATPase activity and alkali stress tolerance by inhibiting TaPP2C.D1/8-mediated dephosphorylation of PM H+-ATPase TaHA2 in wheat.展开更多
The cellulose synthase gene superfamily,including Cellulose synthase A(CesA)and cellulose synthase-like(Csl)gene families,is responsible for the synthesis of cellulose and hemicellulose,respectively.The CesA/Csl genes...The cellulose synthase gene superfamily,including Cellulose synthase A(CesA)and cellulose synthase-like(Csl)gene families,is responsible for the synthesis of cellulose and hemicellulose,respectively.The CesA/Csl genes are vital for abiotic stress resistance and shoot tenderness regulation of tea plants(Camellia sinensis).However,the CesA/Csl gene family has not been extensively studied in tea plants.Here,we identified 53 CsCesA/Csl genes in tea plants.These genes were grouped into five subfamilies(CsCesA,CsCslB,CsCslD,CsCslE,CsCslG)based on the phylogenetic relationships with Arabidopsis and rice.The analysis of chromosome distribution,gene structure,protein domain and motif revealed that most genes in CsCesA,CsCslD and CsCslE subfamilies were conserved,whereas CsCslB and CsCslG subfamily members are highly diverged.The transcriptome analysis showed that most CsCesA/Csl genes displayed tissue-specific expression pattern.In addition,members of CsCslB4,CsCesA1/3/6,CsCslB3/4,CsCslD3,CsCslE1 and CsCslG2/3 subfamilies were up-regulated under drought and cold stresses,indicating their potential roles in regulating stress tolerance in tea plants.Furthermore,the expression levels of CsCslG2_6 and CsCslD3_5 in different tissues and cultivars,respectively,were positively correlated with the cellulose content that is negatively related with shoot tenderness.Thus,these two genes were speculated to be involved in the regulation of shoot tenderness in tea plants.Our findings may help elucidate the evolutionary relationships and expression patterns of the CsCesA/Csl genes in tea plants,and provide more candidate genes responsible for stress tolerance and tenderness regulation in tea plants for future functional research.展开更多
Increasing evidence shows that pathological elevation of plasma fatty acids, especially long-chain saturated forms, which ordinarily occurs in obesity patients, increases the risk
Bacteria fertilizer is used most widely among all kinds of microbial fertilizers. We summarize the research headway of bacteria fertilizer. It mainly focuses on bacteria fertilizer improving the stress resistance of p...Bacteria fertilizer is used most widely among all kinds of microbial fertilizers. We summarize the research headway of bacteria fertilizer. It mainly focuses on bacteria fertilizer improving the stress resistance of plant. Then we can offer basis to research and exploit bacteria fertilizer. These bacteria include azotobacter, photosynthetic bacteria, Bacillus mucilaginosus siliceous, phosphorus bacteria, plant growth-promoting rhizobacteria(PGPR), effective microorganism(EM).展开更多
Soybean(Glycine max)is a major source of plant protein and oil.Soybean breeding has benefited from advances in functional genomics.In particular,the release of soybean reference genomes has advanced our understanding ...Soybean(Glycine max)is a major source of plant protein and oil.Soybean breeding has benefited from advances in functional genomics.In particular,the release of soybean reference genomes has advanced our understanding of soybean adaptation to soil nutrient deficiencies,the molecular mechanism of symbiotic nitrogen(N)fixation,biotic and abiotic stress tolerance,and the roles of flowering time in regional adaptation,plant architecture,and seed yield and quality.Nevertheless,many challenges remain for soybean functional genomics and molecular breeding,mainly related to improving grain yield through high-density planting,maize-soybean intercropping,taking advantage of wild resources,utilization of heterosis,genomic prediction and selection breeding,and precise breeding through genome editing.This review summarizes the current progress in soybean functional genomics and directs future challenges for molecular breeding of soybean.展开更多
The disciplines of evolutionary biology and plant and animal breeding have been intertwined throughout their development,with responses to artificial selection yielding insights into the action of natural selection an...The disciplines of evolutionary biology and plant and animal breeding have been intertwined throughout their development,with responses to artificial selection yielding insights into the action of natural selection and evolutionary biology providing statistical and conceptual guidance for modern breeding.Here we offer an evolutionary perspective on a grand challenge of the 21st century:feeding humanity in the face of climate change.We first highlight promising strategies currently under way to adapt crops to current and future climate change.These include methods to match crop varieties with current and predicted environments and to optimize breeding goals,management practices,and crop microbiomes to enhance yield and sustainable production.We also describe the promise of crop wild relatives and recent technological innovations such as speed breeding,genomic selection,and genome editing for improving environmental resilience of existing crop varieties or for developing new crops.Next,we discuss how methods and theory from evolutionary biology can enhance these existing strategies and suggest novel approaches.We focus initially on methods for reconstructing the evolutionary history of crops and their pests and symbionts,because such historical information provides an overall framework for crop-improvement efforts.We then describe how evolutionary approaches can be used to detect and mitigate the accumulation of deleterious mutations in crop genomes,identify alleles and mutations that underlie adaptation(and maladaptation)to agricultural environments,mitigate evolutionary trade-offs,and improve critical proteins.Continuing feedback between the evolution and crop biology communities will ensure optimal design of strategies for adapting crops to climate change.展开更多
As the source of energy and biological signals,light can influence the healing process of grafted seedlings by regulating the synthesis of the endogenous hormone,regeneration of wound-healing tissue,and connection of ...As the source of energy and biological signals,light can influence the healing process of grafted seedlings by regulating the synthesis of the endogenous hormone,regeneration of wound-healing tissue,and connection of vascular tissue in grafted seedlings.The effect of daily light integral(DLI)on the healing process and seedling quality of tomato(Solanum lycopersicum L.)was analyzed in this study,with the comparison of grafted seedlings treated in dark for 7 d after grafting.The results showed that the height increment of scion and rootstock,adhesion of graft union,stem flow,total chlorophyll content,and net photosynthesis rate increased gradually with increasing light intensity,and no longer increased significantly when the DLI was higher than 5.04 mol/m^(2)·d.The contents of auxin(IAA)and gibberellin(GA)in tomato leaves increased and abscisic acid(ABA)decreased with the increase of DLI.However,there was no significant difference between the treatments with DLI higher than 6.48 mol/m^(2)·d.Both the biomass and energy use efficiency(EUE)of grafted seedlings increased with DLI in a certain range and then decreased.The biomass was the largest when DLI was 5.04 mol/m^(2)·d.However,EUE was highest when DLI was 7.46 mol/m^(2)·d.In conclusion,a suitable DLI is beneficial to cultivate high-quality grafted tomato seedlings,and increasing DLI within a certain range can promote biomass accumulation,connection of vascular tissue,and endogenous hormone biosynthesis in tomato grafted seedlings during the healing period.The lighting environment with DLI of 5.04 mol/m^(2)·d(light intensity of 100μmol/m^(2)·s and light time of 14 h/d)is recommended for the healing treatment in high-quality production,which also improves EUE during the healing period of tomato grafted seedlings.展开更多
基金financial support from the National Key R&D Program of China(2022YFD1201702)the National Natural Science Foundation of China(32272040)the Agricultural Fine Seed Project of Shandong Province,China(2021LZGC006)。
文摘Abiotic stresses, such as drought, salt, extreme temperatures, and heavy metal pollution, are the main environmental factors that limit crop growth and yield. Sorghum, a C4 grass plant with high photosynthetic efficiency, can grow in adverse environmental conditions due to its excellent stress resistance characteristics. Therefore, unraveling the stress-resistance mechanism of sorghum could provide a theoretical basis for developing and cultivating various stress-resistant crops. This understanding could also help to create a conducive environment for using marginal soil in agriculture and ensuring food security. In this review, we discuss the adaptation mechanisms of sorghum under drought, salinity, temperature, and soil heavy metal stresses, the specific response to stress, the screening of sorghum-resistant germplasm, and the identification and functional analysis of the relevant genes and quantitative trait loci(QTL). In addition, we discuss the application potential of different stress-tolerant sorghum germplasms reported to date and emphasize the feasibility and potential use in developing and promoting highly stress-tolerant sorghum in marginal soil.
基金supported by grants from the National Key R&D Program of China(2018YFC1200400)the National Natural Science Foundation of China(31570642)+1 种基金the Fundamental Research Funds for the Central Universities,China(2572019CG04)the Heilongjiang Touyan Innovation Team Program,China(Tree Genetics and Breeding Innovation Team)。
文摘The G protein-coupled receptor(GPCR)regulates downstream genes by binding to a heterotrimeric G protein.However,the function of sex peptide receptor(SPR)in lepidopteran species is mostly unknown.Understanding the physiological functions of SPR in insects is essential for exploring new insecticidal targets.In the present study,the functions of an SPR in Lymantria dispar(Asian gypsy moth;LdSPR)were investigated.The expression of LdSPR was the highest in the 6 th instar larval stage,and there was a large difference in expression between male and female adults.After LdSPR gene silencing,L.dispar larvae showed increased sensitivity to high temperature,starvation,and oxidative stress,indicating that LdSPR enhances stress resistance.These results enrich our knowledge of the function of the insect SPRs,which will lead to a better understanding of other insect GPCR family members and the identification of new targets for the development of environmentally friendly pesticides.
文摘Rapeseed is the largest source of China's edible vegetable oil and plays a pivotal role in China's edible oil market.With global warming and frequent occurrence of various extreme climates,traditional hybrid breeding has been unable to meet the production requirements for rape yield and stress resistance.In recent years,the rapid development and maturity of molecular marker technologies have opened up new ways for stress resistance breeding in rape.This article mainly discusses several types of molecular marker technologies commonly used in rapeseed breeding,such as RFLP,SSR,and SNP,the advantages of molecular marker technologies over conventional breeding and other genetic marker technologies,as well as the application of molecular marker technologies in rapeseed disease resistance,drought resistance,cold resistance and lodging resistance breeding,the current problems and development prospects in breeding.
基金supported by the National Science Foundation of China(No.31360604)
文摘Sophora moorcroftiana(S. moorcroftiana) is an endemic leguminous dwarf shrub in Tibet, China. Decoctions of the seeds have been used in Chinese folk medicine for dephlogistication, detoxication, and infectious diseases. The present study aimed to investigate the constituent and biological effects of polysaccharides from S. moorcroftiana seeds in Caenorhabditis elegans(C. elegans). Polysaccharides from S. moorcroftiana seeds(SMpol) were extracted with 60% ethanol and constituent was analyzed by GC-MS. SMpol was composed of glucose, galactose and inositol in the molar ratio of 35.7 : 1.3 : 17.0. Synchronized worms were treated with SMpol and then lifespan, motility, reproduction, stress resistance and antimicrobial activity were examined. Compared with the control group, the lifespan was increased to the average of 27.3 days and the number of laying eggs showed a 1.3-fold increase in nematodes treated with SMpol(4 mg×mL^(–1)). In SMpol(4 mg×mL^(–1)) treated worms, there was a 1.1-fold increase in 24-h survival of acute heat stress and a 1.6-fold increase in 2-h survival of oxidative stress The colonization of the bacteria in the SMpol treated nematode was significantly lower than that of the untreated group by 68.3%. In vivo studies showed SMpol significantly extended the life span, improved reproduction, increased stress resistance and antimicrobial capacity of C. elegans. In conclusion, those results indicated that the polysaccharides from S. moorcroftiana seeds were involved in a variety of biological activities leading to its modulatory effects on C. elegans which may be developed as a natural supplement agent.
基金supported by the grant of the National Key R&D Program of China(2018YFA0901200)the National Natural Science Foundation of China(31725003,32070103,31860012 and 31800113).L.X.is supported by China Postdoctoral Science Foundation(2018 M631201)and Shaanxi Postdoctoral Science Foundation(2018BSHTDZZ20).
文摘Bacteria inhabit diverse and dynamic environments,where nutrients may be limited and toxic chemicals can be prevalent.To adapt to these stressful conditions,bacteria have evolved specialized protein secretion systems,such as the type VI secretion system(T6SS)to facilitate their survival.As a molecular syringe,the T6SS expels various effectors into neighboring bacterial cells,eukaryotic cells,or the extracellular environment.These effectors improve the competitive fitness and environmental adaption of bacterial cells.Although primarily recognized as antibacterial weapons,recent studies have demonstrated that T6SSs have functions beyond interspecies competition.Here,we summarize recent research on the role of T6SSs in microbiome modulation,pathogenesis,and stress resistance.
文摘[Objectives]To study the germplasm resources of excellent peach cultivars.[Methods]Five peach cultivars were introduced,in-cluding‘Jinxiu’peach,‘Jinxiang’peach,‘Chunxiao’peach,‘Hujingmilu’peach and‘018 nectarine’peach.Then,these five cultivars were used to study the biological characteristics of peach trees,namely,as phenology,fruit quality,heat resistance,cold resistance and other resistance.[Results]Five cultivars of peach plants grew fast and robust,among which‘018 nectarine’had very crisp fruit,‘Jinxiu’,‘Jinxiang’,‘Chunxiao’and‘Hujingmilu’had very sweet fruitꎻthe peach trees of these five cultivars have good water resistance,heat resist-ance and cold resistance.[Conclusions]The results of this study can not only provide a reference for the introduction of peach trees,but also provide a practical basis for the large-scale planting of peach trees.
基金Supported by National Key R&D Program(2017YFC1701503)National Nature Science Foundation of China(81872963)。
文摘Lonicera japonica Thunb.is widely distributed in China.It has strong adaptability to the environment and can maintain normal growth and development under a variety of stress conditions.It is commonly used as a medicine with its dry flower buds or newly opened flowers,named honeysuckle,and with both economic value and ecological application value.The research progress of L.japonica Thunb.under stress conditions such as temperature,drought,light,salt,heavy metals and diseases,pests and endophytic bacteria was reviewed,and the current research situation of the physiological and biochemical response mechanism,changes of photosynthetic fluorescence and accumulation of secondary metabolites of honeysuckle under different stresses was discussed,so as to provide a reference for deep-level exploring the resistance mechanism of L.japonica Thunb.in the future and lay a theoretical foundation for the high-quality authentic ecological cultivation of L.japonica Thunb.
基金Supported by Tianjin Science and Technology Planning Project(17JCYBJC2980016PTZSTG00020)+1 种基金Jinnan Science and Technology Planning Project of Tianjin City(201802055)Undergraduate Innovation and Enterpreneurship Training Program of Tianjin City(0905).
文摘[Objectives]This study was conducted to clarify the saline-alkali tolerance in seedlings of Lonicera caerulea L.[Methods]The L.caerulea seedling variety,Lanjingling,was used as the test material,and alkaline solution(NaHCO 3)with different concentration gradients was used for stress treatment to observe physiological effects on L.caerulea seedlings.[Results]L.caerulea seedlings were most affected by alkaline stress at a treatment concentration of 100 mmol/L,and their osmotic substances(proline,soluble sugar,soluble protein)and antioxidant enzymes(CAT,SOD and POD)were higher in content at a concentration of 100 mmol/L compared with the alkaline stresses in this range.The contents were generally higher,and even in the detection of proline,soluble sugar,SOD and POD,the contents of these substances and enzymes reached a peak at 100 mmol/L.The contents of soluble sugar,CAT,SOD,POD and malondialdehyde were generally higher than that of the control check(CK),and the contents of proline and soluble protein in each treatment concentration were generally higher than that of the CK.[Conclusions]The metabolic physiology of L.caerulea seedlings has a certain adaptability to alkaline stress.
文摘Hypoxic preconditioning is able to increase the body’s resistance to hypoxic/ischemic stress. Understanding how to apply the hypoxic response to initiate the protective mechanism of ischemic preconditioning is a high priority. However, the relationship between innate resistance to hypoxic stress and preconditioning efficiency of moderate hypoxia has been poorly studied. In our work, the efficiency of single moderate hypobaric hypoxia (HBH) for resistance to severe hypobaric hypoxia (SHBH) was studied on intact rats and those pre-tested under SHBH with low, intermediate and high resistance to hypoxia. HBH has a significant preconditioning action on the resistance to hypoxia over a wide range from 270 to 1464 s (4.5 to 24.5 min) and at the same time eliminates the differences in the endurance under SHBH between all rat groups. It is concluded that 1) HBH preconditioning efficiency does not depend on an innate resistance to SHBH and prior hypoxic experience of rats;and 2) the pretesting to severe hypoxia has no value for predicting the hypoxic preconditioning efficiency and study of adaptive mechanisms.
基金The authors would like to acknowledge Professor Jiankang Zhu and his lab at the Shanghai Center for Plant Stress Biology,Chinese Center for Plant Stress Biology,for providing the CRISPR/Cas9 system plasmids.All authors declare no competing financial or nonfinancial interests.This work was funded by the National Natural Science Foundation of China(grant Nos.82225047,32000231,31970316,and 32170274)the National Key Research and Development Program of China(grant no.2022YFC3501703)+1 种基金Shanghai Science and Technology Development Funds(23QA1411400,China)Key project at central government level(The ability establishment of sustainable use for valuable Chinese medicine resources,2060302).
文摘Lignans are a powerful weapon for plants to resist stresses and have diverse bioactive functions to protect human health.Elucidating the mechanisms of stereoselective biosynthesis and response to stresses of lignans is important for the guidance of plant improvement.Here,we identified the complete pathway to stereoselectively synthesize antiviral(-)-lariciresinol glucosides in Isatis indigotica roots,which consists of three-step sequential stereoselective enzymes DIR1/2,PLR,and UGT71B2.DIR1 was further identified as the key gene in respoJanuary 2024nse to stresses and was able to trigger stress defenses by mediating the elevation in lignan content.Mechanistically,the phytohormone-responsive ERF transcription factor LTF1 colocalized with DIR1 in the cell periphery of the vascular regions in mature roots and helped resist biotic and abiotic stresses by directly regulating the expression of DIR1.These systematic results suggest that DIR1 as the first common step of the lignan pathway cooperates with PLR and UGT71B2 to stereoselectively synthesize(-)-lariciresinol derived antiviral lignans in I.indigotica roots and is also a part of the LTF1-mediated regulatory network to resist stresses.In conclusion,the LTF1-DIR1 module is an ideal engineering target to improve plant Defenses while increasing the content of valuable lignans in plants.
文摘[Objectives]To study the adaptability of introduced pear.[Methods]Five pear varieties,"Aidang"pear,"Taiwan Zaomi"pear,"Cuiguan"pear,"Tianjin Yali"pear and"Zaosheng Xinshui"pear,were introduced.Then,using these five varieties,the phenology of pear trees,various characters of fruit,stress resistance(heat tolerance and cold tolerance)of varieties were studied.[Results]The plants of 5 varieties of pear trees grew fast and were robust;in late March,it went into the flowering period;"Aidang"pear fruit had a certain number of stone cells;"Taiwan Zaomi"pear had the highest sweetness;"Cuiguan"pear had the largest fruit;these five varieties of pear trees had good water resistance,heat resistance and cold resistance.[Conclusions]This study can provide a reference for the introduction of pear trees,and can also provide a practical basis for the large-scale planting of pear trees.
基金Supported by Science and Technology Agriculture Project of Shanghai Municipal Commission of Agriculture and Rural Affairs[Hu Nong Ke Tui Zi(2019)No.1-8]Science and Technology Innovation Action Plan of the Science and Technology Commission of Shanghai Municipality(19DZ1203501).
文摘[Objectives]To study the introduction performance of pomegranate(Punica granatum)varieties in Shanghai area.[Methods]In this experiment,five pomegranate varieties were introduced,namely‘American 002’pomegranate,‘Huohulu’pomegranate,‘Wanli No.1’pomegranate,‘Yicheng Hongpitian’pomegranate,and‘American Qingpisuan’pomegranate.Then,using these five varieties,various biological traits such as phenology and fruit quality of pomegranate,as well as stress resistance such as heat resistance and cold resistance were studied.[Results]Five varieties of pomegranates began to mature in succession in early September;the smallest single fruit weight was 90 g,and the largest was 110 g;the plants grew fast,the plants were strong,the flowers were single petal,and plants bore fruits which were ornamental and edible.In addition,the pomegranates of these five varieties had good water tolerance and heat resistance,and good cold resistance.[Conclusions]This study is intended to provide a certain reference for the introduction of pomegranate varieties,and also provide a practical basis for the large-scale planting of pomegranate.
基金supported by the Faculty of Health Sciences,Universiti Teknologi MARA,Puncak Alam Campus,Selangor and LESTARI grant(600-IRMI/MYRA 5/3/LESTARI(16/2016)
文摘Objective: To investigate the effects of Andrographis paniculata(Burm.f.) Wall. Ex Nees(A. paniculata) on expressions and activities of catalase, superoxide dismutase and alkylhydroperoxide reductase C in Staphylococcus aureus(S. aureus) with respect to its survival in vitro. Methods: Antioxidative property of methanolic leaves extract of A. paniculata(0.06 mg/m L). Minimum inhibitory concentration(MIC) was determined by its ability to reduce hydrogen peroxide(H_2O_2) toxicity against S. aureus ATCC 25923(3.8×10~8 cfu/m L). Effects of the extract on expressions of kat A(encoding catalase), sod A and sod M [encoding superoxide dismutases(SODs)], and ahp C [encoding alkylhydroperoxide reductase C(AhpC)] in S. aureuswere determined by RT-q PCR and corresponding enzyme activity assays were performed. Nitroblue tetrazolium reduction(NBT) assay was performed to determine effects of the extract on intracellular and extracellular levels of O_2-in S. aureus. Results: Cells challenged with 7.5 mmol/L H_2O_2 showed 0% survival in 30 min whereas 25% survived after treatment with the extract and H_2O_2. Cells that were treated with the extract alone had 43% survival in the same exposure period. Expressions of sod A and sod M genes in extract-treated cells were lowered 0.8-fold and 0.7-fold, respectively with decrease in total SOD activity of 26.8 U compared to untreated cells, 32.4 U(P<0.05). In contrast, extract-treated S. aureus cells showed 3.3-fold increase in kat A expression with corresponding increase in catalase activity of 1.828 U compared to untreated cells which was 1.248 U,(P<0.05). More profoundly, ahp C expression was increased 61-fold in extract-treated cells,(P<0.05) with corresponding increase in Ahp C activity of 0.018 U compared to untreated cells, 0.012U,(P<0.05). Extract-treated cells had significantly lower intra-and extracellular O_2-levels with absorbance readings(A_(575nm)) of 0.340 and 0.524 compared to untreated cells which were 0.516 and 0.928(P<0.05), respectively. Conclusions: Taken together these results suggest that the low MIC of A. paniculatamethanolic leaves extract(0.06 mg/m L) reduce H_2O_2 toxicity and more importantly, was in itself effectively inhibitory against S. aureus. Further, our observations suggest that a probable mode of its inhibitory mechanism against S. aureus is by reducing total SOD activity through downregulation of sod A and sod M expressions.
基金supported by grants from the Natural Science Foundation of Shandong Province(ZR2020JQ14 and ZR2019ZD16)the National Natural Science Foundation of China(31872864,32171935,31722038,31720103910,and U1906202)+2 种基金the Agricultural Variety Improvement Project of Shandong Province(2022LZGC002)the National Key Research and Development Program of China(2022YFD1201700)the Project for Scientific Research Innovation Team of Young Scholar in Colleges and Universities of Shandong Province(2020KJE002).
文摘Alkali stress is a major constraint for crop production in many regions of saline-alkali land.However,little is known about the mechanisms through which wheat responds to alkali stress.In this study,we identified a calcium ion-binding protein from wheat,TaCCD1,which is critical for regulating the plasma membrane(PM)H^(+)-ATPase-mediated alkali stress response.PM H+-ATPase activity is closely related to alkali tolerance in the wheat variety Shanrong 4(SR4).We found that two D-clade type 2C protein phosphatases,TaPP2C.D1 and TaPP2C.D8(TaPP2C.D1/8),negatively modulate alkali stress tolerance by dephosphorylating the penultimate threonine residue(Thr926)of TaHA2 and thereby inhibiting PM H+-ATPase activity.Alkali stress induces the expression of TaCCD1 in SR4,and TaCCD1 interacts with TaSAUR215,an early auxin-responsive protein.These responses are both dependent on calcium signaling triggered by alkali stress.TaCCD1 enhances the inhibitory effect of TaSAUR215 on TaPP2C.D1/8 activity,thereby promoting the activity of the PM H^(+)-ATPase TaHA2 and alkali stress tolerance in wheat.Functional and genetic analyses verified the effects of these genes in response to alkali stress,indicating that TaPP2C.D1/8 function downstream of TaSAUR215 and TaCCD1.Collectively,this study uncovers a new signaling pathway that regulates wheat responses to alkali stress,in which Ca^(2+)-dependent TaCCD1 cooperates with TaSAUR215 to enhance PM H+-ATPase activity and alkali stress tolerance by inhibiting TaPP2C.D1/8-mediated dephosphorylation of PM H+-ATPase TaHA2 in wheat.
基金the Technology Creation Center of Guizhou Tea Industrialization(Qiankezhongyindi[2017]4005)Training Project for Guizhou Excellent Young Scientific and Technological Talents(Qiankehe Platform Talent[2019]5651)Guizhou Science and Technology Planning Project(Qiankehe Support[2021]General 111)to Litang Lu,and Research Funds for Introduced Talents of Guizhou University to Qi Zhao.
文摘The cellulose synthase gene superfamily,including Cellulose synthase A(CesA)and cellulose synthase-like(Csl)gene families,is responsible for the synthesis of cellulose and hemicellulose,respectively.The CesA/Csl genes are vital for abiotic stress resistance and shoot tenderness regulation of tea plants(Camellia sinensis).However,the CesA/Csl gene family has not been extensively studied in tea plants.Here,we identified 53 CsCesA/Csl genes in tea plants.These genes were grouped into five subfamilies(CsCesA,CsCslB,CsCslD,CsCslE,CsCslG)based on the phylogenetic relationships with Arabidopsis and rice.The analysis of chromosome distribution,gene structure,protein domain and motif revealed that most genes in CsCesA,CsCslD and CsCslE subfamilies were conserved,whereas CsCslB and CsCslG subfamily members are highly diverged.The transcriptome analysis showed that most CsCesA/Csl genes displayed tissue-specific expression pattern.In addition,members of CsCslB4,CsCesA1/3/6,CsCslB3/4,CsCslD3,CsCslE1 and CsCslG2/3 subfamilies were up-regulated under drought and cold stresses,indicating their potential roles in regulating stress tolerance in tea plants.Furthermore,the expression levels of CsCslG2_6 and CsCslD3_5 in different tissues and cultivars,respectively,were positively correlated with the cellulose content that is negatively related with shoot tenderness.Thus,these two genes were speculated to be involved in the regulation of shoot tenderness in tea plants.Our findings may help elucidate the evolutionary relationships and expression patterns of the CsCesA/Csl genes in tea plants,and provide more candidate genes responsible for stress tolerance and tenderness regulation in tea plants for future functional research.
文摘Increasing evidence shows that pathological elevation of plasma fatty acids, especially long-chain saturated forms, which ordinarily occurs in obesity patients, increases the risk
文摘Bacteria fertilizer is used most widely among all kinds of microbial fertilizers. We summarize the research headway of bacteria fertilizer. It mainly focuses on bacteria fertilizer improving the stress resistance of plant. Then we can offer basis to research and exploit bacteria fertilizer. These bacteria include azotobacter, photosynthetic bacteria, Bacillus mucilaginosus siliceous, phosphorus bacteria, plant growth-promoting rhizobacteria(PGPR), effective microorganism(EM).
基金supported by the National Natural Science Foundation of China(32090064 and 31725021 to F.K.,31930083 to B.L.)the Major Program of Guangdong Basic and Applied Research(2019B030302006 to F.K.and B.L.)funded by the National Key Research and Development Program(2021YFF1001203 to B.L.)。
文摘Soybean(Glycine max)is a major source of plant protein and oil.Soybean breeding has benefited from advances in functional genomics.In particular,the release of soybean reference genomes has advanced our understanding of soybean adaptation to soil nutrient deficiencies,the molecular mechanism of symbiotic nitrogen(N)fixation,biotic and abiotic stress tolerance,and the roles of flowering time in regional adaptation,plant architecture,and seed yield and quality.Nevertheless,many challenges remain for soybean functional genomics and molecular breeding,mainly related to improving grain yield through high-density planting,maize-soybean intercropping,taking advantage of wild resources,utilization of heterosis,genomic prediction and selection breeding,and precise breeding through genome editing.This review summarizes the current progress in soybean functional genomics and directs future challenges for molecular breeding of soybean.
基金supported by the Australian Research Councilthe Natural Sciences and Engineering Research Council of Canada,respectively+1 种基金supported by grants from the United States Department of Agriculturethe United States National Science Foundation.
文摘The disciplines of evolutionary biology and plant and animal breeding have been intertwined throughout their development,with responses to artificial selection yielding insights into the action of natural selection and evolutionary biology providing statistical and conceptual guidance for modern breeding.Here we offer an evolutionary perspective on a grand challenge of the 21st century:feeding humanity in the face of climate change.We first highlight promising strategies currently under way to adapt crops to current and future climate change.These include methods to match crop varieties with current and predicted environments and to optimize breeding goals,management practices,and crop microbiomes to enhance yield and sustainable production.We also describe the promise of crop wild relatives and recent technological innovations such as speed breeding,genomic selection,and genome editing for improving environmental resilience of existing crop varieties or for developing new crops.Next,we discuss how methods and theory from evolutionary biology can enhance these existing strategies and suggest novel approaches.We focus initially on methods for reconstructing the evolutionary history of crops and their pests and symbionts,because such historical information provides an overall framework for crop-improvement efforts.We then describe how evolutionary approaches can be used to detect and mitigate the accumulation of deleterious mutations in crop genomes,identify alleles and mutations that underlie adaptation(and maladaptation)to agricultural environments,mitigate evolutionary trade-offs,and improve critical proteins.Continuing feedback between the evolution and crop biology communities will ensure optimal design of strategies for adapting crops to climate change.
基金supported by Postdoctoral Fund in Jiangsu Province(2020Z308)Project Funded by the National Key Research and Development Program of China(2018YFF0213601)+1 种基金Project Funded by the Key Laboratory of Modern Agricultural Equipment and Technology of the Ministry of Education(JNZ201909)Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD-2018-87).
文摘As the source of energy and biological signals,light can influence the healing process of grafted seedlings by regulating the synthesis of the endogenous hormone,regeneration of wound-healing tissue,and connection of vascular tissue in grafted seedlings.The effect of daily light integral(DLI)on the healing process and seedling quality of tomato(Solanum lycopersicum L.)was analyzed in this study,with the comparison of grafted seedlings treated in dark for 7 d after grafting.The results showed that the height increment of scion and rootstock,adhesion of graft union,stem flow,total chlorophyll content,and net photosynthesis rate increased gradually with increasing light intensity,and no longer increased significantly when the DLI was higher than 5.04 mol/m^(2)·d.The contents of auxin(IAA)and gibberellin(GA)in tomato leaves increased and abscisic acid(ABA)decreased with the increase of DLI.However,there was no significant difference between the treatments with DLI higher than 6.48 mol/m^(2)·d.Both the biomass and energy use efficiency(EUE)of grafted seedlings increased with DLI in a certain range and then decreased.The biomass was the largest when DLI was 5.04 mol/m^(2)·d.However,EUE was highest when DLI was 7.46 mol/m^(2)·d.In conclusion,a suitable DLI is beneficial to cultivate high-quality grafted tomato seedlings,and increasing DLI within a certain range can promote biomass accumulation,connection of vascular tissue,and endogenous hormone biosynthesis in tomato grafted seedlings during the healing period.The lighting environment with DLI of 5.04 mol/m^(2)·d(light intensity of 100μmol/m^(2)·s and light time of 14 h/d)is recommended for the healing treatment in high-quality production,which also improves EUE during the healing period of tomato grafted seedlings.