Cotton(Gossypium spp.) yield is reduced by stress. In this study, high temperature(HT) suppressed the expression of the jasmonic acid(JA) biosynthesis gene allene oxide cyclase 2(GhAOC2), reducing JA content and causi...Cotton(Gossypium spp.) yield is reduced by stress. In this study, high temperature(HT) suppressed the expression of the jasmonic acid(JA) biosynthesis gene allene oxide cyclase 2(GhAOC2), reducing JA content and causing male sterility in the cotton HT-sensitive line H05. Anther sterility was reversed by exogenous application of methyl jasmonate(MeJA) to early buds. To elucidate the role of GhAOC2 in JA biosynthesis and identify its putative contribution to the anther response to HT, we created gene knockout cotton plants using the CRISPR/Cas9 system. Ghaoc2 mutant lines showed male-sterile flowers with reduced JA content in the anthers at the tetrad stage(TS), tapetum degradation stage(TDS), and anther dehiscence stage(ADS). Exogenous application of MeJA to early mutant buds(containing TS or TDS anthers) rescued the sterile pollen and indehiscent anther phenotypes, while ROS signals were reduced in ADS anthers. We propose that HT downregulates the expression of GhAOC2 in anthers, reducing JA biosynthesis and causing excessive ROS accumulation in anthers, leading to male sterility. These findings suggest exogenous JA application as a strategy for increasing male fertility in cotton under HT.展开更多
Plant male reproduction is a fine-tuned developmental process that is susceptible to stressful environments and influences crop grain yields.Phytohormone signaling functions in control of plant normal growth and devel...Plant male reproduction is a fine-tuned developmental process that is susceptible to stressful environments and influences crop grain yields.Phytohormone signaling functions in control of plant normal growth and development as well as in response to external stresses,but the interaction or crosstalk among phytohormone signaling,stress response,and male reproduction in plants remains poorly understood.Cross-species comparison among 514 stress-response transcriptomic libraries revealed that ms33-6038,a genic male sterile mutant deficient in the Zm Ms33/Zm GPAT6 gene,displayed an excessive drought stress-like transcriptional reprogramming in anthers triggered mainly by disturbed jasmonic acid(JA)homeostasis.An increased level of JA appeared in Zm Ms33-deficient anthers at both meiotic and postmeiotic stages and activated genes involved in JA biosynthesis and signaling as well as genes functioning in JA-mediated drought response.Excessive accumulation of JA elevated expression level of a gene encoding a WRKY transcription factor that activated the Zm Ms33 promoter.These findings reveal a feedback loop of Zm Ms33-JA-WRKY-Zm Ms33 in controlling male sterility and JA-mediated stress response in maize,shedding light on the crosstalk of stress response and male sterility mediated by phytohormone homeostasis and signaling.展开更多
Drought stress is a limiting factor for wheat production and food security.Drought priming has been shown to increase drought tolerance in wheat.However,the underlying mechanisms are unknown.In the present study,the g...Drought stress is a limiting factor for wheat production and food security.Drought priming has been shown to increase drought tolerance in wheat.However,the underlying mechanisms are unknown.In the present study,the genes encoding the biosynthesis and metabolism of abscisic acid(ABA)and jasmonic acid(JA),as well as genes involved in the ABA and JA signaling pathways were up-regulated by drought priming.Endogenous concentrations of JA and ABA increased following drought priming.The interplay between JA and ABA in plant responses to drought priming was further investigated using inhibitors of ABA and JA biosynthesis.Application of fluridone(FLU)or nordihydroguaiaretic acid(NDGA)to primed plants resulted in lower chlorophyll-fluorescence parameters and activities of superoxide dismutase and glutathione reductase,and higher cell membrane damage,compared to primed plants(PD)under drought stress.NDGA+ABA,but not FLU+JA,restored priming-induced tolerance,as indicated by a finding of no significant difference from PD under drought stress.Under drought priming,NDGA induced the suppression of ABA accumulation,while FLU did not affect JA accumulation.These results were consistent with the expression of genes involved in the biosynthesis of ABA and JA.They suggest that ABA and JA are required for priming-induced drought tolerance in wheat,with JA acting upstream of ABA.展开更多
Jasmonates are class of plant growth regulators act as signal molecule that intercede various components in physiological and metabolic regulation, stress responses and possibly communication through signal transducti...Jasmonates are class of plant growth regulators act as signal molecule that intercede various components in physiological and metabolic regulation, stress responses and possibly communication through signal transduction. Oxidative stress due to heavy metal exposure stimulates synthesis and activity of antioxidant metabolites and enhances antioxidant enzyme activities that could protect plant tissues. The aim of this study was to investigate the exogenous effect of JA at seed level which can transduce throughout seedling growth and regulate antioxidant activities such as superoxide dismutase (SOD;EC 1.15.1.1) and guaiacol peroxidase (POD;EC 1.11.1.7) in 12 days old seedlings of pigeon pea (Cajanus cajan (L.) Millsp.) in presence and/or absence of copper. The activity of SOD and POD increased significantly in presence of Cu2+ after seed priming with JA. JA also helps in chlorophyll and carotenoid accumulation and neutralizes the toxic effect of Cu2+ on seedlings. This is the first report of JA effect on photosynthetic pigment accumulation and H2O2 mitigating enzymes i.e. SOD and POD and it could be recommended that seed priming with JA help in ameliorating toxic effect of Cu2+.展开更多
Cotton fibers are single cells originating in the epidermis of cotton ovules,and serve as the largest natural fiber source for the textile industry.In theory,all epidermal cells have the potential to develop into fibe...Cotton fibers are single cells originating in the epidermis of cotton ovules,and serve as the largest natural fiber source for the textile industry.In theory,all epidermal cells have the potential to develop into fibers,but only 15%–25%of epidermis cells develop into commercially viable lint fibers.We previously showed that Gh Lac1 participates in cotton defense against biotic stress.Here we report that Gh Lac1 also has a role in cotton fiber development.Gh Lac1 RNAi lines in cotton showed increased differentiation of fiber initials from epidermis and shortened fiber length,resulting in unchanged lint percentage.Suppression of Gh Lac1 expression led to constitutively hyperaccumulated jasmonic acid(JA)and flavonoids in ovules and fiber cells.In vitro ovule culture experiments confirmed the distinct roles of JA and flavonoids in fiber initiation and elongation,and showed that fiber development is spatially regulated by these chemicals:the increased fiber initiation in Gh Lac1 RNAi lines is caused by hyperaccumulated JA and rutin content during the fiber initiation stage and shortened fiber length is caused by constitutively increased JA and naringenin content during the fiber elongation stage.展开更多
An alternative to the use of chemical fungicides is to enhance the defensive response of plants by appropriate stimulation, a phenomenon known as induction of resistance. The aim of this study was to determine the cha...An alternative to the use of chemical fungicides is to enhance the defensive response of plants by appropriate stimulation, a phenomenon known as induction of resistance. The aim of this study was to determine the changes of endogen levels of salicylic acid (SA) and jasmonic acid (JA) in potato plants as response to foliar application of biotic and abiotic inductors. Treatments T1 = Best Ultra F (Bacillus spp. 108 cfu/mL and Pseudomonas fluorescens 108 cfu/mL) 0.5%, T2 = FullKover HF (microbial jasmonic acid 1500 ppm) 0.2%, T3 = T1 0.5% + T2 0.1%, T4 = Milor® (Chlorothalonil + Metalaxyl) 0.5% and T5 = control (water) were applied in potato plants. The application of biotic and abiotic inductors improved the SA and JA production in potato plants. The production of salicylic acid in potato plants was observed by application of Bacillus spp. and Pseudomonas fluorescens (T1) and fungicide Milor® (T4). The application of T1 Best Ultra F, T2 FullKover HF (microbial JA), T3 (T1 + T2) and T4 Milor® improved the JA production in potato plants.展开更多
Plants have evolved complex physical and chemical defense systems that allow them to withstand herbivory infestation.Composed of a complex mixture of very-long-chain fatty acids(VLCFAs)and their derivatives,cuticular ...Plants have evolved complex physical and chemical defense systems that allow them to withstand herbivory infestation.Composed of a complex mixture of very-long-chain fatty acids(VLCFAs)and their derivatives,cuticular wax constitutes the first physical line of defense against herbivores.Here,we report the function of Glossy 8(ZmGL8),which encodes a 3-ketoacyl reductase belonging to the fatty acid elongase complex,in orchestrating wax production and jasmonic acid(JA)-mediated defenses against herbivores in maize(Zea mays).The mutation of GL8 enhanced chemical defenses by activating the JA-dependent pathway.We observed a trade-off between wax accumulation and JA levels across maize glossy mutants and 24 globally collected maize inbred lines.In addition,we demonstrated that mutants defective in cuticular wax biosynthesis in Arabidopsis thaliana and maize exhibit enhanced chemical defenses.Comprehensive transcriptomic and lipidomic analyses indicated that the gl8 mutant confers chemical resistance to herbivores by remodeling VLCFA-related lipid metabolism and subsequent JA biosynthesis and signaling.These results suggest that VLCFA-related lipid metabolism has a critical role in regulating the trade-offs between cuticular wax and JA-mediated chemical defenses.展开更多
Anthocyanins are secondary metabolites induced by environmental stimuli and developmental signals.The positive regulators of anthocyanin biosynthesis have been reported,whereas the anthocyanin repressors have been neg...Anthocyanins are secondary metabolites induced by environmental stimuli and developmental signals.The positive regulators of anthocyanin biosynthesis have been reported,whereas the anthocyanin repressors have been neglected.Although the signal transduction pathways of gibberellin(GA)and jasmonic acid(JA)and their regulation of anthocyanin biosynthesis have been investigated,the cross-talk between GA and JA and the antagonistic mechanism of regulating anthocyanin biosynthesis remain to be investigated.In this study,we identified the anthocyanin repressor MdbHLH162 in apple and revealed its molecular mechanism of regulating anthocyanin biosynthesis by integrating the GA and JA signals.MdbHLH162 exerted passive repression by interacting with MdbHLH3 and MdbHLH33,which are two recognized positive regulators of anthocyanin biosynthesis.MdbHLH162 negatively regulated anthocyanin biosynthesis by disrupting the formation of the anthocyanin-activated MdMYB1-MdbHLH3/33complexes and weakening transcriptional activation of the anthocyanin biosynthetic genes MdDFR and MdUF3GT by MdbHLH3 and MdbHLH33.The GA repressor MdRGL2a antagonized MdbHLH162-mediated inhibition of anthocyanins by sequestering MdbHLH162 from the MdbHLH162-MdbHLH3/33 complex.The JA repressors MdJAZ1 and MdJAZ2 interfered with the antagonistic regulation of MdbHLH162 by MdRGL2a by titrating the formation of the MdRGL2a-MdbHLH162 complex.Our findings reveal that MdbHLH162 integrates the GA and JA signals to negatively regulate anthocyanin biosynthesis.This study provides new information for discovering more anthocyanin biosynthesis repressors and explores the cross-talk between hormone signals.展开更多
The essential micronutrient boron(B) has key roles in cell wall integrity and B deficiency inhibits plant growth. The role of jasmonic acid(JA) in plant growth inhibition under B deficiency remains unclear. Here,we re...The essential micronutrient boron(B) has key roles in cell wall integrity and B deficiency inhibits plant growth. The role of jasmonic acid(JA) in plant growth inhibition under B deficiency remains unclear. Here,we report that low B elevates JA biosynthesis in Arabidopsis thaliana by inducing the expression of JA biosynthesis genes. Treatment with JA inhibited plant growth and, a JA biosynthesis inhibitor enhanced plant growth, indicating that the JA induced by B deficiency affects plant growth. Furthermore,examination of the JA signaling mutants jasmonate resistant1, coronatine insensitive1-2, and myc2 showed that JA signaling negatively regulates plant growth under B deficiency. We identified a low-B responsive transcription factor, ERF018, and used yeast one-hybrid assays and transient activation assays in Nicotiana benthamiana leaf cells to demonstrate that ERF018 activates the expression of JA biosynthesis genes. ERF018 overexpression(OE)lines displayed stunted growth and up-regulation of JA biosynthesis genes under normal B conditions,compared to Col-0 and the difference between ERF018 OE lines and Col-0 diminished under low B.These results suggest that ERF018 enhances JA biosynthesis and thus negatively regulates plant growth. Taken together, our results highlight the importance of JA in the effect of low B on plant growth.展开更多
Fusarium head blight(FHB),mainly caused by the fungal pathogen Fusarium graminearum,is one of the most destructive wheat diseases.Besides directly affecting the yield,the mycotoxin residing in the kernel greatly threa...Fusarium head blight(FHB),mainly caused by the fungal pathogen Fusarium graminearum,is one of the most destructive wheat diseases.Besides directly affecting the yield,the mycotoxin residing in the kernel greatly threatens the health of humans and livestock.Xinong 979(XN979)is a widely cultivated wheat elite with high yield and FHB resistance.However,its resistance mechanism remains unclear.In this study,we studied the expression of genes involved in plant defense in XN979 by comparative transcriptomics.We found that the FHB resistance in XN979 consists of two lines of defense.The first line of defense,which is constitutive,is knitted via the enhanced basal expression of lignin and jasmonic acid(JA)biosynthesis genes.The second line of defense,which is induced upon F.graminearum infection,is contributed by the limited suppression of photosynthesis and the struggle of biotic stress-responding genes.Meanwhile,the effective defense in XN979 leads to an inhibition of fungal gene expression,especially in the early infection stage.The formation of the FHB resistance in XN979 may coincide with the breeding strategies,such as selecting high grain yield and lodging resistance traits.This study will facilitate our understanding of wheat-F.graminearum interaction and is insightful for breeding FHB-resistant wheat.展开更多
Poor seedling emergence is a challenge for direct seeding of rice under deep-sowing field conditions.Here we reveal that UDP-glucosyltransferase OsUGT75A promotes rice seedling emergence under deepsowing conditions by...Poor seedling emergence is a challenge for direct seeding of rice under deep-sowing field conditions.Here we reveal that UDP-glucosyltransferase OsUGT75A promotes rice seedling emergence under deepsowing conditions by increasing shoot length.Expression of OsUGT75A was higher in the middle regions of the shoot and in shoots under deep-sowing conditions.Levels of free abscisic acid(ABA)and jasmonates(JA)were higher in shoots of OsUGT75A mutants than in those of wild-type plants,and OsUGT75A mutants were more sensitive to ABA and JA treatments.Reduced shoot length was attributed to higher ABA INSENSITIVE 3(OsABI3)expression and lower JASMONATE-ZIM domain protein(OsJAZ)expression in shoots.Shoot extension by OsUGT75A is achieved mainly by promotion of cell elongation.An elite haplotype of OsUGT75A associated with increased shoot length was identified among indica rice accessions.OsUGT75A acts to increase seedling emergence under deep-sowing conditions.展开更多
Auxin is throughout the entire life process of plants and is involved in the crosstalk with other hormones,yet its role in apple disease resistance remains unclear.In this study,we investigated the function of auxin/i...Auxin is throughout the entire life process of plants and is involved in the crosstalk with other hormones,yet its role in apple disease resistance remains unclear.In this study,we investigated the function of auxin/indole-3-acetic acid(IAA)gene Md IAA24 overexpression in enhancing apple resistance to Glomerella leaf spot(GLS)caused by Colletotrichum fructicola(Cf).Analysis revealed that,upon Cf infection,35S::Md IAA24 plants exhibited enhanced superoxide dismutase(SOD)and peroxidase(POD)activity,as well as a greater amount of glutathione(reduced form)and ascorbic acid accumulation,resulting in less H_(2)O_(2)and superoxide anion(O_(2)^(-))in apple leaves.Furthermore,35S::Md IAA24 plants produced more protocatechuic acid,proanthocyanidins B1,proanthocyanidins B2 and chlorogenic acid when infected with Cf.Following Cf infection,35S::Md IAA24 plants presented lower levels of IAA and jasmonic acid(JA),but higher levels of salicylic acid(SA),along with the expression of related genes.The overexpression of Md IAA24 was observed to enhance the activity of chitinase andβ-1,3-glucanase in Cfinfected leaves.The results indicated the ability of Md IAA24 to regulate the crosstalk between IAA,JA and SA,and to improve reactive oxygen species(ROS)scavenging and defense-related enzymes activity.This jointly contributed to GLS resistance in apple.展开更多
Jasmonic acid(JA)is thought to be involved in plant responses to cadmium(Cd)stress,but the underlying molecular mechanisms are poorly understood.Here,we show that Cd treatment rapidly induces the expression of genes p...Jasmonic acid(JA)is thought to be involved in plant responses to cadmium(Cd)stress,but the underlying molecular mechanisms are poorly understood.Here,we show that Cd treatment rapidly induces the expression of genes promoting endogenous JA synthesis,and subsequently increases the JA concentration in Arabidopsis roots.Furthermore,exogenous methyl jasmonate(MeJA)alleviates Cd-generated chlorosis of new leaves by decreasing the Cd concentration in root cell sap and shoot,and decreasing the expression of the AtIRT1,AtHMA2 and AtHMA4 genes promoting Cd uptake and long-distance translocation,respectively.In contrast,mutation of a key JA synthesis gene,At AOS,greatly enhances the expression of AtIRT1,AtHMA2 and AtHMA4,increases Cd concentration in both roots and shoots,and confers increased sensitivity to Cd.Exogenous Me JA recovers the enhanced Cd-sensitivity of the ataos mutant,but not of atcoi1,a JA receptor mutant.In addition,exogenous Me JA reduces NO levels in Cd-stressed Arabidopsis root tips.Taken together,our results suggest that Cd-induced JA acts via the JA signaling pathway and its effects on NO levels to positively restrict Cd accumulation and alleviates Cd toxicity in Arabidopsis via suppression of the expression of genes promoting Cd uptake and long-distance translocation.展开更多
Nitric oxide (NO) has emerged as a key signaling molecule in plant secondary metabolite biosynthesis recently. In order to investigate the molecular basis of NO signaling in elicitor-induced secondary metabolite biosy...Nitric oxide (NO) has emerged as a key signaling molecule in plant secondary metabolite biosynthesis recently. In order to investigate the molecular basis of NO signaling in elicitor-induced secondary metabolite biosynthesis of plant cells, we determined the contents of NO, salicylic acid (SA), jasmonic acid (JA), and puerarin in Pueraria thomsonii Benth. suspension cells treated with the elicitors prepared from cell walls of Penicillium citrinum. The results showed that the fungal elicitor induced NO burst, SA accumulation and puerarin production of P. thomsonii Benth. cells. The elicitor-induced SA accumulation and puerarin production was suppressed by nitric oxide specific scavenger cPITO, indicating that NO was essential for elicitor-induced SA and puerarin biosynthesis in P. thomsonii Benth. cells. In transgenic NahG P. thomsonii Benth. cells, the fungal elicitor also induced puerarin biosynthesis, NO burst, and JA accumulation, though the SA biosynthe-sis was impaired. The elicitor-induced JA accumulation in transgenic cells was blocked by cPITO, which suggested that JA acted downstream of NO and its biosynthesis was controlled by NO. External application of NO via its donor sodium nitroprusside (SNP) enhanced puerarin biosynthesis in trans-genic NahG P. thomsonii Benth. cells, and the NO-triggered puerarin biosynthesis was suppressed by JA inhibitors IBU and NDGA, which indicated that NO induced puerarin production through a JA-dependent signal pathway in the transgenic cells. Exogenous application of SA suppressed the elicitor-induced JA biosynthesis and reversed the inhibition of IBU and NDGA on elicitor-induced pu-erarin accumulation in transgenic cells, which indicated that SA inhibited JA biosynthesis in the cells and that SA might be used as a substitute for JA to mediate the elicitor- and NO-induced puerarin biosynthesis. It was, therefore, concluded that NO might mediate the elicitor-induced puerarin bio-synthesis through SA- and JA-dependent signal pathways in wildtype P. thomsonii Benth. cells and transgenic NahG cells respectively.展开更多
Pea seedlings (Pisum sativum L.) were used as materials to test the timings and compartments of hydrogen peroxide (H2O2) triggered by wounding and exogenous jasmonic acid (JA). The results showed that H2O2 could be sy...Pea seedlings (Pisum sativum L.) were used as materials to test the timings and compartments of hydrogen peroxide (H2O2) triggered by wounding and exogenous jasmonic acid (JA). The results showed that H2O2 could be systemically induced by wounding and exogenous JA. H2O2 increased within 1 h and reached the peak 3―5 h after wounding in either the wounded leaves or the unwounded leaves adjacent to the wounded ones and the inferior leaves far from the wounded ones. After this, H2O2 decreased and recovered to the control level 12 h after wounding. The activities of antioxidant enzymes, however, were rapidly increased by wounding. Diphenylene iodonium (DPI), an inhibitor of NADPH oxidase, could significantly inhibit H2O2 burst that was mediated by wounding and exogenous JA. Assay of H2O2 subcellular location showed that H2O2 in response to wounding and exogenous JA was predominantly accumulated in plasma membrane, cell wall and apoplasmic space. Numerous JA (gold particles) was found via immu- nogold electron microscopy to be located in cell wall and phloem zones of mesophyll cell after wounding.展开更多
In rice, the characterization of OsEBP-89 is inducible by various stress- or hormone-stimuli, including ethylene, abscisic acid (ABA), jasmonate acid (JA), drought and cold. Here, we report the investigation of essent...In rice, the characterization of OsEBP-89 is inducible by various stress- or hormone-stimuli, including ethylene, abscisic acid (ABA), jasmonate acid (JA), drought and cold. Here, we report the investigation of essential DNA region within OsEBP-89 promoter for methyl jasmonic acid (MeJA) induction. PLACE analysis indicates that this promoter sequence contains multiple potential elements in response to various stimuli. First, we fused this promoter with GUS gene and analyzed its expression under MeJA treatment through Agrobacterium infiltration mediating transient expression in tobacco leaves. Our results revealed that this chimeric gene could be inducible by MeJA in tobacco leaves. To further de- termine the crucial sequences responsible for MeJA induction, we generated a series of deletion pro- moters which were fused with GUS reporter gene respectively. The results of transient expression of GUS gene driven by these mutant promoters show that the essential region for MeJA induction is po- sitioned in the region between -1200 and -800 in OsEBP-89 promoter containing a G-box (?1127), which is distinct from the essential region containing ERE (?562) for ACC induction. In all, our finding is helpful in understanding the molecular mechanism of OsEBP-89 expression under different stimuli.展开更多
The jasmonic acid(JA)signaling pathway is used by plants to control wound responses.The persistent accumulation of JA inhibits plant growth,and the hydroxylation of JA to 12-hydroxy-JA by JASMONATE-INDUCED OXYGENASEs(...The jasmonic acid(JA)signaling pathway is used by plants to control wound responses.The persistent accumulation of JA inhibits plant growth,and the hydroxylation of JA to 12-hydroxy-JA by JASMONATE-INDUCED OXYGENASEs(JOXs,also named jasmonic acid oxidases)is therefore vital for plant growth,while structural details of JA recognition by JOXs are unknown.Here,we present the 2.65Åresolution X-ray crystal structure of Arabidopsis JOX2 in complex with its substrate JA and its co-substrates 2-oxoglutarate and Fe(Ⅱ).JOX2 contains a distorted double-stranded p helix(DSBH)core flanked by a helices and loops.JA is bound in the narrow substrate pocket by hydrogen bonds with the arginine triad R225,R350,and R354 and by hydrophobic interactions mainly with the phenylalanine triad F157,F317,and F346.The most critical residues for JA binding are F157 and R225,both from the DSBH core,which interact with the cyclopentane ring of JA.The spatial distribution of critical residues for JA binding and the shape of the substrate-binding pocket together define the substrate selectivity of the JOXs.Sequence alignment shows that these critical residues are conserved among JOXs from higher plants.Collectively,our study provides insights into the mechanism by which higher plants hydroxylate the hormone JA.展开更多
Until recently,many studies on the role of phytohormones in plant secondary metabolism focused on jasmonic acid(JA),salicylic acid(SA),gibberellins(GA),and abscisic acid(ABA).It is now clear that phytohormone?induced ...Until recently,many studies on the role of phytohormones in plant secondary metabolism focused on jasmonic acid(JA),salicylic acid(SA),gibberellins(GA),and abscisic acid(ABA).It is now clear that phytohormone?induced regulation of signaling occurs via regulation of the biosynthetic pathway genes at the transcriptional level or through posttranslational regulation,or an increase in secondary metabolite deposition(e.g.,trichomes).Here,we summarize recent advances,updating the current reports on the molecular machinery of phytohormones JA,SA,GA,and ABA involved in plant secondary metabolites.This review emphasizes the differences and similarities among the four phytohormones in regulating various secondary metabolic biosynthetic pathways and also provides suggestions for further research.展开更多
Transcription factors(TFs)play essential roles in transcriptional reprogramming during activation of plant immune responses to pathogens.OsSPL10(SQUAMOSA promoter binding protein-like10)is an important TF regulating t...Transcription factors(TFs)play essential roles in transcriptional reprogramming during activation of plant immune responses to pathogens.OsSPL10(SQUAMOSA promoter binding protein-like10)is an important TF regulating trichome development and salt tolerance in rice.Here we report that knockout of OsSPL10 reduces whereas its overexpression enhances rice resistance to blast disease.OsSPL10 positively regulates chitin-induced immune responses including reactive oxygen species(ROS)burst and callose deposition.We show that OsSPL10 physically associates with OsJAmyb,an important TF involved in jasmonic acid(JA)signaling,and positively regulates its protein stability.We then prove that OsJAmyb positively regulates resistance to blast.Our results reveal a molecular module consisting of OsSPL10 and OsJAmyb that positively regulates blast resistance.展开更多
基金funding support from the National Natural Science Foundation of China (32072024)the Fundamental Research Funds for the Central Universities (2021ZKPY019)the National Key Research and Development Program of China (2018YFD0100403, 2016YFD0101402)。
文摘Cotton(Gossypium spp.) yield is reduced by stress. In this study, high temperature(HT) suppressed the expression of the jasmonic acid(JA) biosynthesis gene allene oxide cyclase 2(GhAOC2), reducing JA content and causing male sterility in the cotton HT-sensitive line H05. Anther sterility was reversed by exogenous application of methyl jasmonate(MeJA) to early buds. To elucidate the role of GhAOC2 in JA biosynthesis and identify its putative contribution to the anther response to HT, we created gene knockout cotton plants using the CRISPR/Cas9 system. Ghaoc2 mutant lines showed male-sterile flowers with reduced JA content in the anthers at the tetrad stage(TS), tapetum degradation stage(TDS), and anther dehiscence stage(ADS). Exogenous application of MeJA to early mutant buds(containing TS or TDS anthers) rescued the sterile pollen and indehiscent anther phenotypes, while ROS signals were reduced in ADS anthers. We propose that HT downregulates the expression of GhAOC2 in anthers, reducing JA biosynthesis and causing excessive ROS accumulation in anthers, leading to male sterility. These findings suggest exogenous JA application as a strategy for increasing male fertility in cotton under HT.
基金funded by the National Key Research and Development Program of China (2021YFF1000302,2022YFF1003500, and 2022YFF1002400)the Fundamental Research Funds for the Central Universities of China (FRF-IDRY-20-038 and 06500136)the National Natural Science Foundation of China (31971958)。
文摘Plant male reproduction is a fine-tuned developmental process that is susceptible to stressful environments and influences crop grain yields.Phytohormone signaling functions in control of plant normal growth and development as well as in response to external stresses,but the interaction or crosstalk among phytohormone signaling,stress response,and male reproduction in plants remains poorly understood.Cross-species comparison among 514 stress-response transcriptomic libraries revealed that ms33-6038,a genic male sterile mutant deficient in the Zm Ms33/Zm GPAT6 gene,displayed an excessive drought stress-like transcriptional reprogramming in anthers triggered mainly by disturbed jasmonic acid(JA)homeostasis.An increased level of JA appeared in Zm Ms33-deficient anthers at both meiotic and postmeiotic stages and activated genes involved in JA biosynthesis and signaling as well as genes functioning in JA-mediated drought response.Excessive accumulation of JA elevated expression level of a gene encoding a WRKY transcription factor that activated the Zm Ms33 promoter.These findings reveal a feedback loop of Zm Ms33-JA-WRKY-Zm Ms33 in controlling male sterility and JA-mediated stress response in maize,shedding light on the crosstalk of stress response and male sterility mediated by phytohormone homeostasis and signaling.
基金supported by the National Key Research and Development Program of China(2016YFD0300107)the National Natural Science Foundation of China(31771693,U1803235)+3 种基金the Fundamental Research Funds for the Central Universities(KYZ201807)the China Agricultural Research System(CARS-03)the Jiangsu Collaborative Innovation Center for Modern Crop Production(JCIC-MCP)the 111 Project(B16026)。
文摘Drought stress is a limiting factor for wheat production and food security.Drought priming has been shown to increase drought tolerance in wheat.However,the underlying mechanisms are unknown.In the present study,the genes encoding the biosynthesis and metabolism of abscisic acid(ABA)and jasmonic acid(JA),as well as genes involved in the ABA and JA signaling pathways were up-regulated by drought priming.Endogenous concentrations of JA and ABA increased following drought priming.The interplay between JA and ABA in plant responses to drought priming was further investigated using inhibitors of ABA and JA biosynthesis.Application of fluridone(FLU)or nordihydroguaiaretic acid(NDGA)to primed plants resulted in lower chlorophyll-fluorescence parameters and activities of superoxide dismutase and glutathione reductase,and higher cell membrane damage,compared to primed plants(PD)under drought stress.NDGA+ABA,but not FLU+JA,restored priming-induced tolerance,as indicated by a finding of no significant difference from PD under drought stress.Under drought priming,NDGA induced the suppression of ABA accumulation,while FLU did not affect JA accumulation.These results were consistent with the expression of genes involved in the biosynthesis of ABA and JA.They suggest that ABA and JA are required for priming-induced drought tolerance in wheat,with JA acting upstream of ABA.
文摘Jasmonates are class of plant growth regulators act as signal molecule that intercede various components in physiological and metabolic regulation, stress responses and possibly communication through signal transduction. Oxidative stress due to heavy metal exposure stimulates synthesis and activity of antioxidant metabolites and enhances antioxidant enzyme activities that could protect plant tissues. The aim of this study was to investigate the exogenous effect of JA at seed level which can transduce throughout seedling growth and regulate antioxidant activities such as superoxide dismutase (SOD;EC 1.15.1.1) and guaiacol peroxidase (POD;EC 1.11.1.7) in 12 days old seedlings of pigeon pea (Cajanus cajan (L.) Millsp.) in presence and/or absence of copper. The activity of SOD and POD increased significantly in presence of Cu2+ after seed priming with JA. JA also helps in chlorophyll and carotenoid accumulation and neutralizes the toxic effect of Cu2+ on seedlings. This is the first report of JA effect on photosynthetic pigment accumulation and H2O2 mitigating enzymes i.e. SOD and POD and it could be recommended that seed priming with JA help in ameliorating toxic effect of Cu2+.
基金financially supported by the National Transgenic Plant Research Program of China(2016ZX08005-001)the Program of Introducing Talents of Discipline to Universities in China(B14032)+1 种基金the open funds of the National Key Laboratory of Crop Genetic Improvement(ZK201901)the National Natural Science Foundation of China(31771837)。
文摘Cotton fibers are single cells originating in the epidermis of cotton ovules,and serve as the largest natural fiber source for the textile industry.In theory,all epidermal cells have the potential to develop into fibers,but only 15%–25%of epidermis cells develop into commercially viable lint fibers.We previously showed that Gh Lac1 participates in cotton defense against biotic stress.Here we report that Gh Lac1 also has a role in cotton fiber development.Gh Lac1 RNAi lines in cotton showed increased differentiation of fiber initials from epidermis and shortened fiber length,resulting in unchanged lint percentage.Suppression of Gh Lac1 expression led to constitutively hyperaccumulated jasmonic acid(JA)and flavonoids in ovules and fiber cells.In vitro ovule culture experiments confirmed the distinct roles of JA and flavonoids in fiber initiation and elongation,and showed that fiber development is spatially regulated by these chemicals:the increased fiber initiation in Gh Lac1 RNAi lines is caused by hyperaccumulated JA and rutin content during the fiber initiation stage and shortened fiber length is caused by constitutively increased JA and naringenin content during the fiber elongation stage.
文摘An alternative to the use of chemical fungicides is to enhance the defensive response of plants by appropriate stimulation, a phenomenon known as induction of resistance. The aim of this study was to determine the changes of endogen levels of salicylic acid (SA) and jasmonic acid (JA) in potato plants as response to foliar application of biotic and abiotic inductors. Treatments T1 = Best Ultra F (Bacillus spp. 108 cfu/mL and Pseudomonas fluorescens 108 cfu/mL) 0.5%, T2 = FullKover HF (microbial jasmonic acid 1500 ppm) 0.2%, T3 = T1 0.5% + T2 0.1%, T4 = Milor® (Chlorothalonil + Metalaxyl) 0.5% and T5 = control (water) were applied in potato plants. The application of biotic and abiotic inductors improved the SA and JA production in potato plants. The production of salicylic acid in potato plants was observed by application of Bacillus spp. and Pseudomonas fluorescens (T1) and fungicide Milor® (T4). The application of T1 Best Ultra F, T2 FullKover HF (microbial JA), T3 (T1 + T2) and T4 Milor® improved the JA production in potato plants.
基金supported by the National Science Foundation of China to Chun-Peng Song (U21A20206)the National Natural Science Foundation of China (32102187)+4 种基金Hainan Province Joint Cultivation Project (2021JJLH0014)to Xi Zhangthe Project of Sanya Yazhou Bay Science and Technology City (SCKJ-JYRC-2022-78) to Bao Zhu Lithe Program for Innovative Research Team (in Science and Technology) in the University of Henan Province (21IRTSTHN019) to Siyi Guothe Program of Introducing Talents of Discipline to Universities (111 Project, number D16014)Henan Province Key Research and Development Project (221111112200) to Shutang Zhou and Xi Zhang
文摘Plants have evolved complex physical and chemical defense systems that allow them to withstand herbivory infestation.Composed of a complex mixture of very-long-chain fatty acids(VLCFAs)and their derivatives,cuticular wax constitutes the first physical line of defense against herbivores.Here,we report the function of Glossy 8(ZmGL8),which encodes a 3-ketoacyl reductase belonging to the fatty acid elongase complex,in orchestrating wax production and jasmonic acid(JA)-mediated defenses against herbivores in maize(Zea mays).The mutation of GL8 enhanced chemical defenses by activating the JA-dependent pathway.We observed a trade-off between wax accumulation and JA levels across maize glossy mutants and 24 globally collected maize inbred lines.In addition,we demonstrated that mutants defective in cuticular wax biosynthesis in Arabidopsis thaliana and maize exhibit enhanced chemical defenses.Comprehensive transcriptomic and lipidomic analyses indicated that the gl8 mutant confers chemical resistance to herbivores by remodeling VLCFA-related lipid metabolism and subsequent JA biosynthesis and signaling.These results suggest that VLCFA-related lipid metabolism has a critical role in regulating the trade-offs between cuticular wax and JA-mediated chemical defenses.
基金financially supported by grants from the Natural Science Foundation of Shandong Province(ZR2022YQ24)the Development Plan of the Youth Innovation Team of the Higher Education Institutions in Shandong Province(2022KJ326)Wuhan Botanical Garden Scientific Research Support Project(E3559901)。
文摘Anthocyanins are secondary metabolites induced by environmental stimuli and developmental signals.The positive regulators of anthocyanin biosynthesis have been reported,whereas the anthocyanin repressors have been neglected.Although the signal transduction pathways of gibberellin(GA)and jasmonic acid(JA)and their regulation of anthocyanin biosynthesis have been investigated,the cross-talk between GA and JA and the antagonistic mechanism of regulating anthocyanin biosynthesis remain to be investigated.In this study,we identified the anthocyanin repressor MdbHLH162 in apple and revealed its molecular mechanism of regulating anthocyanin biosynthesis by integrating the GA and JA signals.MdbHLH162 exerted passive repression by interacting with MdbHLH3 and MdbHLH33,which are two recognized positive regulators of anthocyanin biosynthesis.MdbHLH162 negatively regulated anthocyanin biosynthesis by disrupting the formation of the anthocyanin-activated MdMYB1-MdbHLH3/33complexes and weakening transcriptional activation of the anthocyanin biosynthetic genes MdDFR and MdUF3GT by MdbHLH3 and MdbHLH33.The GA repressor MdRGL2a antagonized MdbHLH162-mediated inhibition of anthocyanins by sequestering MdbHLH162 from the MdbHLH162-MdbHLH3/33 complex.The JA repressors MdJAZ1 and MdJAZ2 interfered with the antagonistic regulation of MdbHLH162 by MdRGL2a by titrating the formation of the MdRGL2a-MdbHLH162 complex.Our findings reveal that MdbHLH162 integrates the GA and JA signals to negatively regulate anthocyanin biosynthesis.This study provides new information for discovering more anthocyanin biosynthesis repressors and explores the cross-talk between hormone signals.
基金This work was funded by the National Natural Science Foundation of China(31772380 and 31972483)the Fundamental Research Funds for the Central Universities of China(2662017QD039,2662019PY058,2662019PY013)。
文摘The essential micronutrient boron(B) has key roles in cell wall integrity and B deficiency inhibits plant growth. The role of jasmonic acid(JA) in plant growth inhibition under B deficiency remains unclear. Here,we report that low B elevates JA biosynthesis in Arabidopsis thaliana by inducing the expression of JA biosynthesis genes. Treatment with JA inhibited plant growth and, a JA biosynthesis inhibitor enhanced plant growth, indicating that the JA induced by B deficiency affects plant growth. Furthermore,examination of the JA signaling mutants jasmonate resistant1, coronatine insensitive1-2, and myc2 showed that JA signaling negatively regulates plant growth under B deficiency. We identified a low-B responsive transcription factor, ERF018, and used yeast one-hybrid assays and transient activation assays in Nicotiana benthamiana leaf cells to demonstrate that ERF018 activates the expression of JA biosynthesis genes. ERF018 overexpression(OE)lines displayed stunted growth and up-regulation of JA biosynthesis genes under normal B conditions,compared to Col-0 and the difference between ERF018 OE lines and Col-0 diminished under low B.These results suggest that ERF018 enhances JA biosynthesis and thus negatively regulates plant growth. Taken together, our results highlight the importance of JA in the effect of low B on plant growth.
基金This work was supported by the grants from the National Key R&D Program of China(2022YFD1400100)the National Natural Science Foundation of China(32072505 and 31701747)+1 种基金the Chinese Universities Scientific Fund(2452020222)the National Innovation and Entrepreneurship Training Program for College Students China(202110712255)。
文摘Fusarium head blight(FHB),mainly caused by the fungal pathogen Fusarium graminearum,is one of the most destructive wheat diseases.Besides directly affecting the yield,the mycotoxin residing in the kernel greatly threatens the health of humans and livestock.Xinong 979(XN979)is a widely cultivated wheat elite with high yield and FHB resistance.However,its resistance mechanism remains unclear.In this study,we studied the expression of genes involved in plant defense in XN979 by comparative transcriptomics.We found that the FHB resistance in XN979 consists of two lines of defense.The first line of defense,which is constitutive,is knitted via the enhanced basal expression of lignin and jasmonic acid(JA)biosynthesis genes.The second line of defense,which is induced upon F.graminearum infection,is contributed by the limited suppression of photosynthesis and the struggle of biotic stress-responding genes.Meanwhile,the effective defense in XN979 leads to an inhibition of fungal gene expression,especially in the early infection stage.The formation of the FHB resistance in XN979 may coincide with the breeding strategies,such as selecting high grain yield and lodging resistance traits.This study will facilitate our understanding of wheat-F.graminearum interaction and is insightful for breeding FHB-resistant wheat.
基金supported by the Key-Area Research and Development Program of Guangdong Province(2022B0202060006)the Natural Science Foundation of Guangdong Province(2023A1515012052,2023A1515012092)+2 种基金the Science and Technology Project of Guangzhou(2023A04J0749,2023A04J1452)the Special Fund for Student Cultivation of Scientific and Technological Innovation of Guangdong Province(pdjh2021b0084)the Double First-Class Discipline Promotion Project of South China Agricultural University(2021B10564001).
文摘Poor seedling emergence is a challenge for direct seeding of rice under deep-sowing field conditions.Here we reveal that UDP-glucosyltransferase OsUGT75A promotes rice seedling emergence under deepsowing conditions by increasing shoot length.Expression of OsUGT75A was higher in the middle regions of the shoot and in shoots under deep-sowing conditions.Levels of free abscisic acid(ABA)and jasmonates(JA)were higher in shoots of OsUGT75A mutants than in those of wild-type plants,and OsUGT75A mutants were more sensitive to ABA and JA treatments.Reduced shoot length was attributed to higher ABA INSENSITIVE 3(OsABI3)expression and lower JASMONATE-ZIM domain protein(OsJAZ)expression in shoots.Shoot extension by OsUGT75A is achieved mainly by promotion of cell elongation.An elite haplotype of OsUGT75A associated with increased shoot length was identified among indica rice accessions.OsUGT75A acts to increase seedling emergence under deep-sowing conditions.
基金supported by the National Key Research and Development Program of China(Grant No.2018YFD1000307)the National Natural Science Foundation of China(Grant No.32172529)+2 种基金the Special Funds for Major Scientific and Technological Innovation from Shaanxi Province(Grant No.2020zdzx03-0101)the Earmarked Fund for China Agriculture Research System(Grant No.CARS-27)China Postdoctoral Science Foundation(Grant Nos.2017M610657,2018T111108)。
文摘Auxin is throughout the entire life process of plants and is involved in the crosstalk with other hormones,yet its role in apple disease resistance remains unclear.In this study,we investigated the function of auxin/indole-3-acetic acid(IAA)gene Md IAA24 overexpression in enhancing apple resistance to Glomerella leaf spot(GLS)caused by Colletotrichum fructicola(Cf).Analysis revealed that,upon Cf infection,35S::Md IAA24 plants exhibited enhanced superoxide dismutase(SOD)and peroxidase(POD)activity,as well as a greater amount of glutathione(reduced form)and ascorbic acid accumulation,resulting in less H_(2)O_(2)and superoxide anion(O_(2)^(-))in apple leaves.Furthermore,35S::Md IAA24 plants produced more protocatechuic acid,proanthocyanidins B1,proanthocyanidins B2 and chlorogenic acid when infected with Cf.Following Cf infection,35S::Md IAA24 plants presented lower levels of IAA and jasmonic acid(JA),but higher levels of salicylic acid(SA),along with the expression of related genes.The overexpression of Md IAA24 was observed to enhance the activity of chitinase andβ-1,3-glucanase in Cfinfected leaves.The results indicated the ability of Md IAA24 to regulate the crosstalk between IAA,JA and SA,and to improve reactive oxygen species(ROS)scavenging and defense-related enzymes activity.This jointly contributed to GLS resistance in apple.
基金supported by National Key R&D Program of China(2016YFD0100704)111 project(B14027)fundamental research fund for central Universities.
文摘Jasmonic acid(JA)is thought to be involved in plant responses to cadmium(Cd)stress,but the underlying molecular mechanisms are poorly understood.Here,we show that Cd treatment rapidly induces the expression of genes promoting endogenous JA synthesis,and subsequently increases the JA concentration in Arabidopsis roots.Furthermore,exogenous methyl jasmonate(MeJA)alleviates Cd-generated chlorosis of new leaves by decreasing the Cd concentration in root cell sap and shoot,and decreasing the expression of the AtIRT1,AtHMA2 and AtHMA4 genes promoting Cd uptake and long-distance translocation,respectively.In contrast,mutation of a key JA synthesis gene,At AOS,greatly enhances the expression of AtIRT1,AtHMA2 and AtHMA4,increases Cd concentration in both roots and shoots,and confers increased sensitivity to Cd.Exogenous Me JA recovers the enhanced Cd-sensitivity of the ataos mutant,but not of atcoi1,a JA receptor mutant.In addition,exogenous Me JA reduces NO levels in Cd-stressed Arabidopsis root tips.Taken together,our results suggest that Cd-induced JA acts via the JA signaling pathway and its effects on NO levels to positively restrict Cd accumulation and alleviates Cd toxicity in Arabidopsis via suppression of the expression of genes promoting Cd uptake and long-distance translocation.
基金supported by the National Natural Science Foundation of China(Grant No.30572331)the Natural Science Foundation of Zhejiang Province(Grant No.302785).
文摘Nitric oxide (NO) has emerged as a key signaling molecule in plant secondary metabolite biosynthesis recently. In order to investigate the molecular basis of NO signaling in elicitor-induced secondary metabolite biosynthesis of plant cells, we determined the contents of NO, salicylic acid (SA), jasmonic acid (JA), and puerarin in Pueraria thomsonii Benth. suspension cells treated with the elicitors prepared from cell walls of Penicillium citrinum. The results showed that the fungal elicitor induced NO burst, SA accumulation and puerarin production of P. thomsonii Benth. cells. The elicitor-induced SA accumulation and puerarin production was suppressed by nitric oxide specific scavenger cPITO, indicating that NO was essential for elicitor-induced SA and puerarin biosynthesis in P. thomsonii Benth. cells. In transgenic NahG P. thomsonii Benth. cells, the fungal elicitor also induced puerarin biosynthesis, NO burst, and JA accumulation, though the SA biosynthe-sis was impaired. The elicitor-induced JA accumulation in transgenic cells was blocked by cPITO, which suggested that JA acted downstream of NO and its biosynthesis was controlled by NO. External application of NO via its donor sodium nitroprusside (SNP) enhanced puerarin biosynthesis in trans-genic NahG P. thomsonii Benth. cells, and the NO-triggered puerarin biosynthesis was suppressed by JA inhibitors IBU and NDGA, which indicated that NO induced puerarin production through a JA-dependent signal pathway in the transgenic cells. Exogenous application of SA suppressed the elicitor-induced JA biosynthesis and reversed the inhibition of IBU and NDGA on elicitor-induced pu-erarin accumulation in transgenic cells, which indicated that SA inhibited JA biosynthesis in the cells and that SA might be used as a substitute for JA to mediate the elicitor- and NO-induced puerarin biosynthesis. It was, therefore, concluded that NO might mediate the elicitor-induced puerarin bio-synthesis through SA- and JA-dependent signal pathways in wildtype P. thomsonii Benth. cells and transgenic NahG cells respectively.
基金This work was supported by the National Natural Science Foundation of China(Grant No.30270918)the National High Technology Research and Development Program of China(863 ProgramGrant No.2003AA241170).
文摘Pea seedlings (Pisum sativum L.) were used as materials to test the timings and compartments of hydrogen peroxide (H2O2) triggered by wounding and exogenous jasmonic acid (JA). The results showed that H2O2 could be systemically induced by wounding and exogenous JA. H2O2 increased within 1 h and reached the peak 3―5 h after wounding in either the wounded leaves or the unwounded leaves adjacent to the wounded ones and the inferior leaves far from the wounded ones. After this, H2O2 decreased and recovered to the control level 12 h after wounding. The activities of antioxidant enzymes, however, were rapidly increased by wounding. Diphenylene iodonium (DPI), an inhibitor of NADPH oxidase, could significantly inhibit H2O2 burst that was mediated by wounding and exogenous JA. Assay of H2O2 subcellular location showed that H2O2 in response to wounding and exogenous JA was predominantly accumulated in plasma membrane, cell wall and apoplasmic space. Numerous JA (gold particles) was found via immu- nogold electron microscopy to be located in cell wall and phloem zones of mesophyll cell after wounding.
基金Supported by the National Basic Research Program of China (Grant No. 2006CB101700)the National Natural Science Foundation of China (Grant Nos. 30671135, 30525034 and 30730060)
文摘In rice, the characterization of OsEBP-89 is inducible by various stress- or hormone-stimuli, including ethylene, abscisic acid (ABA), jasmonate acid (JA), drought and cold. Here, we report the investigation of essential DNA region within OsEBP-89 promoter for methyl jasmonic acid (MeJA) induction. PLACE analysis indicates that this promoter sequence contains multiple potential elements in response to various stimuli. First, we fused this promoter with GUS gene and analyzed its expression under MeJA treatment through Agrobacterium infiltration mediating transient expression in tobacco leaves. Our results revealed that this chimeric gene could be inducible by MeJA in tobacco leaves. To further de- termine the crucial sequences responsible for MeJA induction, we generated a series of deletion pro- moters which were fused with GUS reporter gene respectively. The results of transient expression of GUS gene driven by these mutant promoters show that the essential region for MeJA induction is po- sitioned in the region between -1200 and -800 in OsEBP-89 promoter containing a G-box (?1127), which is distinct from the essential region containing ERE (?562) for ACC induction. In all, our finding is helpful in understanding the molecular mechanism of OsEBP-89 expression under different stimuli.
基金supported by grants from the National Key Research and Development Program of China(grant no.2016YFD0300700)the National Natural Science Foundation of China(youth grant,no.32000859)+1 种基金the Project for Extramural Scientists of the State Key Laboratory of Agrobiotechnology(project ID:2020SKLAB6-26)The research of R.S.and G.V.d.A.was financed in part by grants from the Dutch Research Council(NWO).
文摘The jasmonic acid(JA)signaling pathway is used by plants to control wound responses.The persistent accumulation of JA inhibits plant growth,and the hydroxylation of JA to 12-hydroxy-JA by JASMONATE-INDUCED OXYGENASEs(JOXs,also named jasmonic acid oxidases)is therefore vital for plant growth,while structural details of JA recognition by JOXs are unknown.Here,we present the 2.65Åresolution X-ray crystal structure of Arabidopsis JOX2 in complex with its substrate JA and its co-substrates 2-oxoglutarate and Fe(Ⅱ).JOX2 contains a distorted double-stranded p helix(DSBH)core flanked by a helices and loops.JA is bound in the narrow substrate pocket by hydrogen bonds with the arginine triad R225,R350,and R354 and by hydrophobic interactions mainly with the phenylalanine triad F157,F317,and F346.The most critical residues for JA binding are F157 and R225,both from the DSBH core,which interact with the cyclopentane ring of JA.The spatial distribution of critical residues for JA binding and the shape of the substrate-binding pocket together define the substrate selectivity of the JOXs.Sequence alignment shows that these critical residues are conserved among JOXs from higher plants.Collectively,our study provides insights into the mechanism by which higher plants hydroxylate the hormone JA.
基金funded by the National Key R&D Program of China(2019YFC1711000)the National Science and Technology Major Project(2017ZX09101002-003-002)+3 种基金the Shanghai Rising-Star Program(18QB1402700,China)Shanghai local Science and Technology Development Fund Program guided by the Central Government(YDZX20203100002948)the Shanghai Natural Science Foundation in China(20ZR1453800)the National Natural Science Foundation of China(32070332,81673550,81874335)。
文摘Until recently,many studies on the role of phytohormones in plant secondary metabolism focused on jasmonic acid(JA),salicylic acid(SA),gibberellins(GA),and abscisic acid(ABA).It is now clear that phytohormone?induced regulation of signaling occurs via regulation of the biosynthetic pathway genes at the transcriptional level or through posttranslational regulation,or an increase in secondary metabolite deposition(e.g.,trichomes).Here,we summarize recent advances,updating the current reports on the molecular machinery of phytohormones JA,SA,GA,and ABA involved in plant secondary metabolites.This review emphasizes the differences and similarities among the four phytohormones in regulating various secondary metabolic biosynthetic pathways and also provides suggestions for further research.
基金supported by grants from Natural Science Foundation Key Program of Fujian Province(2023J02011)National Natural Science Foundation of China(31970281,31671668)+1 种基金a Sino-German Mobility Program funded jointly by National Natural Science Foundation of ChinaGerman Research Foundation(M-0275).
文摘Transcription factors(TFs)play essential roles in transcriptional reprogramming during activation of plant immune responses to pathogens.OsSPL10(SQUAMOSA promoter binding protein-like10)is an important TF regulating trichome development and salt tolerance in rice.Here we report that knockout of OsSPL10 reduces whereas its overexpression enhances rice resistance to blast disease.OsSPL10 positively regulates chitin-induced immune responses including reactive oxygen species(ROS)burst and callose deposition.We show that OsSPL10 physically associates with OsJAmyb,an important TF involved in jasmonic acid(JA)signaling,and positively regulates its protein stability.We then prove that OsJAmyb positively regulates resistance to blast.Our results reveal a molecular module consisting of OsSPL10 and OsJAmyb that positively regulates blast resistance.
