Jasmonic acid （JA） is a fatty acid-derived signaling molecule that regulates a broad range of plant defense responses against herbivores and some microbial pathogens. Molecular genetic studies have established that ...Jasmonic acid （JA） is a fatty acid-derived signaling molecule that regulates a broad range of plant defense responses against herbivores and some microbial pathogens. Molecular genetic studies have established that JA also performs a critical role in several aspects of plant development. Here, we describe the characterization of the Arabidopsis mutantjasmonic acid-hypersensitivel-1 （jah1-1）, which is defective in several aspects of JA responses. Although the mutant exhibits increased sensitivity to JA in root growth inhibition, it shows decreased expression of JA-inducible defense genes and reduced resistance to the necrotrophic fungus Botrytis cinerea. Gene cloning studies indicate that these defects are caused by a mutation in the cytochrome P450 protein CYP82C2. We provide evidence showing that the compromised resistance of thejah1-1 mutant to B. cinerea is accompanied by decreased expression of JA-induced defense genes and reduced accumulation of JA-induced indole glucosinolates （IGs）. Conversely, the enhanced resistance to B. cinerea in CYP82C2-overexpressing plants is accompanied by increased expression of JA-induced defense genes and elevated levels of JA-induced IGs. We demonstrate that CYP82C2 affects JA-induced accumulation of the IG biosynthetic precursor tryptophan （Trp）, but not the JA-induced IAA or pathogen-induced camalexin. Together, our results support a hypothesis that CYP82C2 may act in the metabolism of Trp-derived secondary metabolites under conditions in which JA levels are elevated. Thejah1-1 mutant should thus be important in future studies toward understanding the mechanisms underlying the complexity of JA-mediated differential responses, which are important for plants to adapt their growth to the ever-changing environments.展开更多
Messenger RNA （mRNA） turnover in eukaryotic cells begins with shortening of the poly （A） tail at the 3＇ end, a process called deadenylation. In yeast, the deadenylation reaction is predominantly mediated by CCR4 ...Messenger RNA （mRNA） turnover in eukaryotic cells begins with shortening of the poly （A） tail at the 3＇ end, a process called deadenylation. In yeast, the deadenylation reaction is predominantly mediated by CCR4 and CCR4- associated factor 1 （CAF1）, two components of the well-characterised protein complex named CCR4-NOT. We report here that AtCAF1a and AtCAF1b, putative Arabidopsis homologs of the yeast CAF1 gene, partially complement the growth defect of the yeast call mutant in the presence of caffeine or at high temperatures. The expression of At-CAF1a and AtCAFlb is induced by multiple stress-related hormones and stimuli. Both AtCAF1a and AtCAFlb show deadenylation activity in vitro and point mutations in the predicted active sites disrupt this activity. T-DNA insertion mutants disrupting the expression of AtCAF1a and/or AtCAF1b are defective in deadenylation of stress-related mRNAs, indicating that the two AtCAF1 proteins are involved in regulated mRNA deadenylation in vivo. Interestingly, the single and double mutants of AtCAF1a and AtCAFlb show reduced expression of pathogenesis-related （PR） genes PR1 and PR2 and are more susceptible to Pseudomonas syringae pv tomato DC3000 （Pst DC3000） infection, whereas transgenic plants over-expressing AtCAFla show elevated expression of PR1 and PR2 and increased resis-tance to the same pathogen. Our results suggest roles of the AtCAF1 proteins in regulated mRNA deadenylation and defence responses to pathogen infections.展开更多
Decades of physiological and molecular studies have demonstrated that plants rely on a diverse set of small molecule hormones to regulate every aspect of their biological processes including development,growth and ada...Decades of physiological and molecular studies have demonstrated that plants rely on a diverse set of small molecule hormones to regulate every aspect of their biological processes including development,growth and adaptation.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 is very harmful to grain yield due to its adverse effect on reproduction, especially on pollination process in rice. However, the molecular basis of such an effect still remains largely unknown. Here, we repor...Drought is very harmful to grain yield due to its adverse effect on reproduction, especially on pollination process in rice. However, the molecular basis of such an effect still remains largely unknown. Here, we report the role of a member of CBL （Calcineurin B-Like） Interacting Protein Kinase （CIPK） family, OsCIPK23, in pollination and stress responses in rice. Molecular analyses revealed that it is mainly expressed in pistil and anther but up-regulated by pollination, as well as by treatments of various abiotic stresses and phytohormones. RNA interference-mediated suppression of OsCIPK23 expression significantly reduced seed set and conferred a hypersensitive response to drought stress, indicating its possible roles in pollination and drought stress. In consistent, overexpression of OsCIPK23 induced the expression of several drought tolerance related genes. Taken together, these results indicate that OsCIPK23 is a multistress induced gene and likely mediates a signaling pathway commonly shared by both pollination and drought stress responses in rice.展开更多
Xiaoyan 60(XY60) is a new wheat variety bred in the laboratory of Zhensheng Li.After salt treatment, seedlings of XY60 maintain green leaves and produce longer roots than the high yielding cultivar Zhongmai 175(ZM175)...Xiaoyan 60(XY60) is a new wheat variety bred in the laboratory of Zhensheng Li.After salt treatment, seedlings of XY60 maintain green leaves and produce longer roots than the high yielding cultivar Zhongmai 175(ZM175).To explain these different phenotypes we carried out an RNA-Seq analysis using 12 samples from three tissues of both varieties subjected to salt and control treatments.By comparing data from the salt treated plants with the control, 703, 979, and 1197 differentially expressed genes(DEGs) were detected in new leaves, old leaves, and roots of XY60, respectively.The corresponding numbers for ZM175 were 613, 1401, and 1301.The most significantly enriched Gene Ontology(GO) terms and KEGG pathways were associated with polyunsaturated fatty acid(PUFA) metabolism in both new and old leaves from XY60.They were associated with photosynthesis and energy metabolism in ZM175.The most significantly enriched KEGG pathway in roots of both varieties was “glucosinolate biosynthesis”.In addition, jasmonic acid(JA) concentration in XY60 was higher than in ZM175, although it increased significantly in both varieties following salt treatment.Trends in relative expression levels of AOS, MYC2, and JAZ revealed by qRT-PCR were concordant with those from RNA-Seq.Our results suggest that PUFAs may contribute to salt tolerance in common wheat by enhancing the photosynthetic system and JA-related pathways.展开更多
RNA helicases are adenosine tri-phosphatases that unwind the secondary structures of RNAs and are required in almost any aspect of RNA metabolism. They are highly conserved from prokaryotic to eukaryotic organisms. Ho...RNA helicases are adenosine tri-phosphatases that unwind the secondary structures of RNAs and are required in almost any aspect of RNA metabolism. They are highly conserved from prokaryotic to eukaryotic organisms. However, their precise roles in plant physiology and development remain to be clarified. Here we report that the mutation in the gene SLOW WALKER3 （SWA3） results in the slow and retarded progression of mitosis during megagametogenesis in Arabidopsis. SWA3 is a putative RNA helicase of the DEAD-box subfamily. Mutant megagametophyte development is arrested at fouror eight-nucleate stages, furthermore, one of the synergids in about half of the mutant embryo sacs displays abnormal polarity, with its nucleus locating at the chalazal end, instead of the micropylar end in the wild-type. Transmission of the mutation through female gametophytes is severely reduced in swa3. However, a small portion of mutant embryo sacs are able to develop into mature and functional female gametophytes when pollination was postponed. The SWA3 in Arabidopsis is a homolog of Dbp8 in yeast. Dbp8 interacts with Efs2 and is essential for biogenesis of 18S rRNA in yeast. Our data suggest that SWA3 may form a complex with AtEfs2 and take roles in ribosomal biogenesis as RNA helicase during megagametogenesis in Arabidopsis.展开更多
Dear Editor,Tomato systemin(TomSys),the first discovered plant peptide hormone,can initiate systemic mobile signals to stimulate an immune response in both wounded and intact leaves(Pearce et al.,1991).For decades,bio...Dear Editor,Tomato systemin(TomSys),the first discovered plant peptide hormone,can initiate systemic mobile signals to stimulate an immune response in both wounded and intact leaves(Pearce et al.,1991).For decades,biologists have been striving to uncover the mechanisms of TomSys function,but detailed information on the TomSys-regulated systemic defense process remains limited to date.The specific roles of three potential transmissible signaling components,ProSys mRNA,TomSys,and jasmonic acid(JA),in activation of systemic defense responses still need to be clarified(Zhang et al.,2020).展开更多
Dear Editor,The world faces unprecedented challenges for crop yield improvement to feed an expanding human population under limited agricultural resources and an increasingly erratic climate(Wheeler and von Braun,2013...Dear Editor,The world faces unprecedented challenges for crop yield improvement to feed an expanding human population under limited agricultural resources and an increasingly erratic climate(Wheeler and von Braun,2013).Bread wheat is one of the most widely cultivated cereal crops,with both grain and flag leaf morphologies determining final yield potential(Xie et al.,2015;Zanella et al.,2023).Candidate genes affecting these traits are therefore highly desirable targets for breeding programs.展开更多
Plant hormones are small molecular natural products that regulate all plant developmental processes at low concentrations. Quantitative analysis of plant hormones is increasingly important for in-depth study of their ...Plant hormones are small molecular natural products that regulate all plant developmental processes at low concentrations. Quantitative analysis of plant hormones is increasingly important for in-depth study of their biosynthesis,transport,metabolism and molecular regulatory mechanisms. Although plant hormone analysis remains a bottleneck in plant scientific research owing to the trace concentrations and complex components in plant crude extracts,much progress has been achieved in the development of extraction,purification and detection techniques in recent years. Solid phase extraction and chromatography/mass spectrometry have been applied widely for purification and quantitative analysis of plant hormones owing to their high selectivity and sensitivity. Purification methods such as liquid partition and immunoaffinity chromatography,and detection methods including immunoassay and electrochemical analysis,are employed. The advantages and disadvantages of these methods are discussed. In situ,real-time and multi-plant hormone profiling will comprise mainstream techniques for quantitative analyses in future studies on the regulatory mechanisms and crosstalk of plant hormones.展开更多
Pollen fertility is a crucial factor for successful pollination and essential for seed formation. Recent studies have suggested that a diverse range of internal and external factors, signaling components and their rel...Pollen fertility is a crucial factor for successful pollination and essential for seed formation. Recent studies have suggested that a diverse range of internal and external factors, signaling components and their related pathways are likely involved in pollen fertility. Here, we report a single C2-domain containing protein, OsPBP1, initially identified through cDNA microarray analysis. OsPBP1 is a single copy gene and preferentially expressed in pistil and pollen but downregulated by pollination. OsPBP1 had a calcium concentration-dependent phospholipid-binding activity and was localized mainly in cytoplasm and nucleus, but translocated onto the plasma membrane in response to an intracellular Ca^2＋ increase. Pollen grains of antisense OsPBP1 transgenic lines were largely nonviable, germinated poorly in vitro and of low fertility. OsPBP1 protein was localized in a region peripheral to pollen wall and vesicles of elongating pollen tube, and its repressed expression reduced substantially this association and led to alteration of microfilament polymerization during pollen germination. Taken together, these results indicate that OsPBP1 is a novel functional C2-domain phospholipids-binding protein that is required for pollen fertility likely by regulating Ca^2＋ and phospholipid signaling pathways.展开更多
Tomato （Solanum lycopersicum） is the leading vegetable crop worldwide and an essential component of a healthy diet （Lin et al., 2014; Du et al., 2017）. Fruit color is regarded as one of the most important commerci...Tomato （Solanum lycopersicum） is the leading vegetable crop worldwide and an essential component of a healthy diet （Lin et al., 2014; Du et al., 2017）. Fruit color is regarded as one of the most important commercial traits in tomato （The Tomato Genome Consortium, 2012）. Consumers in different regions have different color preferences. For example, European and American consumers prefer red tomatoes, while pink tomatoes are more pop- ular in Asia countries, particularly in China and Japan （Ballester et al., 2010; Lin et al., 2014）. However, most of tomato breeding ma- terials are red-fruited, thus the generation of pink-fruited materials is very important for Asian tomato production. Metabolomics and genetics studies demonstrate that the pink trait results from the absence of yellow-colored flavonoid naringenin chalcone （NarCh） in the peels,展开更多
One of the hottest topics in plant hormone biology is the crosstalk mechanisms,whereby multiple classes of phytohormones interplay with each other through signaling networks.To better understand the roles of hormonal ...One of the hottest topics in plant hormone biology is the crosstalk mechanisms,whereby multiple classes of phytohormones interplay with each other through signaling networks.To better understand the roles of hormonal crosstalks in their complex regulatory networks,it is of high significance to investigate the spatial and temporal distributions of multiple-phytohormones simultaneously from one plant tissue sample.In this study,we develop a high-sensitivity and high-throughput method for the simultaneous quantitative analysis of 44 phytohormone compounds,covering currently known 10 major classes of phytohormones(strigolactones,brassinosteroids,gibberellins,auxin,abscisic acid,jasmonic acid,salicylic acid,cytokinins,ethylene,and polypeptide hormones[e.g.,phytosulfokine])from only 100 mg of plant sample.These compounds were grouped and purified separately with a tailored solid-phase extraction procedure based on their physicochemical properties and then analyzed by LC–MS/MS.The recoveries of our method ranged from 49.6%to 99.9%and the matrix effects from 61.8%to 102.5%,indicating that the overall sample pretreatment design resulted in good purification.The limits of quantitation(LOQs)of our method ranged from 0.06 to 1.29 pg/100 mg fresh weight and its precision was less than 13.4%,indicating high sensitivity and good reproducibility of the method.Tests of our method in different plant matrices demonstrated its wide applicability.Collectively,these advantages will make our method helpful in clarifying the crosstalk networks of phytohormones.展开更多
Detection of protein-protein interaction can provide valuable information for investigating the biological function of proteins.The current methods that applied in protein-protein interaction,such as co-immunoprecipit...Detection of protein-protein interaction can provide valuable information for investigating the biological function of proteins.The current methods that applied in protein-protein interaction,such as co-immunoprecipitation and pull down etc.,often cause plenty of working time due to the burdensome cloning and puri-fication procedures.Here we established a system that characterization of protein-protein interaction was accomplished by co-expression and simply purification of target proteins from one expression cassette within E.coli system.We modified pET vector into co-expression vector pInvivo which encoded PPV NIa protease,two cleavage site F and two multiple cloning sites that flanking cleavage sites.The target proteins(for example:protein A and protein B)were inserted at multiple cloning sites and translated into polyprotein in the order of MBP tag-protein A-site F-PPV NIa protease-site F-protein B-His6 tag.PPV NIa protease carried out intracellular cleavage along expression,then led to the separation of polyprotein components,therefore,the interaction between protein A-protein B can be detected through one-step purification and analysis.Negative control for protein B was brought into this system for monitoring interaction specificity.We successfully employed this system to prove two cases of reported protien-protein interaction:RHA2a/ANAC and FTA/FTB.In conclusion,a convenient and efficient system has been successfully developed for detecting protein-protein interaction.展开更多
Plants rely on a diverse set of small-molecule hormones to regu- late every aspect of their biological processes including develop- ment, growth, and adaptation. Since the discovery of the first plant hormone, auxin, ...Plants rely on a diverse set of small-molecule hormones to regu- late every aspect of their biological processes including develop- ment, growth, and adaptation. Since the discovery of the first plant hormone, auxin, hormones have always been at the frontier of plant biology.展开更多
Dietary anthocyanins are important health-promoting antioxidants that make a major contribution to the quality of fruits. It is intriguing that most tomato cultivars do not produce anthocyanins in fruit. However, the ...Dietary anthocyanins are important health-promoting antioxidants that make a major contribution to the quality of fruits. It is intriguing that most tomato cultivars do not produce anthocyanins in fruit. However, the purple tomato variety Indigo Rose, which has the dominant Aft locus combined with the recessive atv locus from wild tomato species, exhibits light-dependent anthocyanin accumulation in the fruit skin. Here, we report that Aft encodes a functional anthocyanin activator named SlAN2-like, while atv encodes a nonfunctional version of the anthocyanin repressor SlMYBATV. The expression of SlAN2-like is responsive to light, and the functional SlAN2-like can activate the expression of both anthocyanin biosynthetic genes and their regulatory genes, suggesting that SlAN2-like acts as a master regulator in the activation of anthocyanin biosynthesis. We further showed that cultivated tomatoes contain nonfunctional alleles of SlAN2-like and therefore fail to produce anthocyanins. Consistently, expression of a functional SlAN2-like gene driven by the fruit-specific promoter in a tomato cultivar led to the activation of the entire anthocyanin biosynthesis pathway and high-level accumulation of anthocyanins in both the peel and flesh. Taken together, our study exemplifies that efficient engineering of complex metabolic pathways could be achieved through tissue-specific expression of master transcriptional regulators.展开更多
Grain size is one of the key agronomic traits that determine grain yield in crops. However, the mechanisms underlying grain size control in crops remain elusive. Here we demonstrate that the OsMKKK10-OsMKK4- OsMAPK6 s...Grain size is one of the key agronomic traits that determine grain yield in crops. However, the mechanisms underlying grain size control in crops remain elusive. Here we demonstrate that the OsMKKK10-OsMKK4- OsMAPK6 signaling pathway positively regulates grain size and weight in rice. In rice, loss of OsMKKKIO function results in small and light grains, short panicles, and semi-dwarf plants, while overexpression of constitutively active OsMKKK10 （CA-OsMKKK10） results in large and heavy grains, long panicles, and tall plants. OsMKKK10 interacts with and phosphorylates OsMKK4. We identified an OsMKK4 gain-of-func- tion mutant （large11-1D）that produces large and heavy grains. OsMKK4A227T encoded by the large11-1D allele has stronger kinase activity than OsMKK4. Plants overexpressing a constitutively active form of OsMKK4 （OsMKK4oDD） also produce large grains. Further biochemical and genetic analyses revealed that OsMKKK10, OsMKK4, and OsMAPK6 function in a common pathway to control grain size. Taken together, our study establishes an important genetic and molecular framework for OsMKKK10-OsMKK4- OsMAPK6 cascade-mediated control of grain size and weight in rice.展开更多
Wound-inducible proteinase inhibitors （PIs） in tomato plants provide a useful model system to elucidate the signal transduction pathways that regulate systemic defense response. Among the proposed intercellular sign...Wound-inducible proteinase inhibitors （PIs） in tomato plants provide a useful model system to elucidate the signal transduction pathways that regulate systemic defense response. Among the proposed intercellular signals for wound-induced PIs expression are the peptide systemin and the oxylipin-derived phytohormone jasmonic acid （JA）. An increasing body of evidence indicates that systemin and JA work in the same signaling pathway to activate the ex- pression of PIs and other defense-related genes. However, relatively less is known about how these signals interact to promote cell-to-cell communication over long distances. Genetic analysis of the systemin/JA signaling pathway in tomato plants provides a unique opportunity to study, in a single experimental system, the mechanism by which peptide and oxylipin signals interact to coordinate systemic expression of defense-related genes. Previously, it has been proposed that systemin is the long-distance mobile signal for defense gene expression. Recently, grafting experiments with tomato mutants defective in JA biosynthesis and signaling provide new evidence that JA, rather than systemin, functions as the systemic wound signal, and that the biosynthesis of JA is regulated by the peptide systemin. Further understanding of the systemin/JA signaling pathway promises to provide new insights into the basic mechanisms governing plant defense to biotic stress.展开更多
Tocopherols synthesized exclusively by photosynthetic organisms are major antioxidants in biomembranes.In plants,tocopherol cyclase(TC/VTE1) catalyzes the conversion of 2,3-dimethyl-5-phytyl-1,4-benzoquinone(DMPBQ) to...Tocopherols synthesized exclusively by photosynthetic organisms are major antioxidants in biomembranes.In plants,tocopherol cyclase(TC/VTE1) catalyzes the conversion of 2,3-dimethyl-5-phytyl-1,4-benzoquinone(DMPBQ) to γ-tocopherol.In the present study,OsVTE1,which encodes a rice tocopherol cyclase ortholog,was cloned and characterized.OsVTE1 was induced significantly by abiotic stresses such as high salt,H2O2,drought,cold and by the plant hormones ABA and salicylic acid.The tissue-specific expression pattern and OsVTE1-promoter GUS activity assay showed that OsVTE1 was mainly expressed in the leaf,and also could be detected in the root,stem and panicle.Compared with control plants,transgenic plants with OsVTE1 RNA interference(OsVTE1-RNAi) were more sensitive to salt stress whereas,in contrast,transgenic plants overexpressing OsVTE1(OsVTE1-OX) showed higher tolerance to salt stress.The DAB in vivo staining showed that OsVTE1-OX plants accumulated less H2O2 than did control plants.展开更多
As one of the most important vegetables,tomato (Solanum lycopersicum) is extensively produced and consumed worldwide and substantially contributes to human nutrition and health (The Tomato Genome Consortium,2012).Alth...As one of the most important vegetables,tomato (Solanum lycopersicum) is extensively produced and consumed worldwide and substantially contributes to human nutrition and health (The Tomato Genome Consortium,2012).Although red tomatoes are the most common,pink tomatoes are more popular in Asia,particularly in China and Japan,because of their better taste (Ballester et al.,2010;Zhu et al.,2018).Compared with red tomatoes,pink tomatoes fail to accumulate the yellow-colored flavonoid pigment,naringenin chalcone (NarCh),in their peels,resulting in a colorless peel phenotype (Adato et al,2009;Ballester et al.,2010).展开更多
基金We gratefully acknowledge Dr Jianru Zuo （Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, China） for providing T-DNA mutagenized population of Arabidopsis, Dr Salome Prat （Institut de Biologia Molecular de Barcelona, Spain） for providing homozygous atmyc2-2 mutant （T-DNA insertion line SALK_083483） seeds and Dr Jane Glazebrook for assisting with camalexin measurements. This work was supported by grants from the Chinese Academy of Sciences （KSCX2- YW-N-045, KSCX2-YW-N-015）, the Ministry of Agriculture of China （2008ZX08009-003-001） and the Ministry of Science and Technology of China （2007CB948201, 2006AA10A116）. Work in the laboratory of Jerry D Cohen was supported by grants from the US National Science Foundation （MCB-0725149 and DBI- PGRP-0606666） and the USDA, National Research Initiative （2005-35318-16197）.
文摘Jasmonic acid （JA） is a fatty acid-derived signaling molecule that regulates a broad range of plant defense responses against herbivores and some microbial pathogens. Molecular genetic studies have established that JA also performs a critical role in several aspects of plant development. Here, we describe the characterization of the Arabidopsis mutantjasmonic acid-hypersensitivel-1 （jah1-1）, which is defective in several aspects of JA responses. Although the mutant exhibits increased sensitivity to JA in root growth inhibition, it shows decreased expression of JA-inducible defense genes and reduced resistance to the necrotrophic fungus Botrytis cinerea. Gene cloning studies indicate that these defects are caused by a mutation in the cytochrome P450 protein CYP82C2. We provide evidence showing that the compromised resistance of thejah1-1 mutant to B. cinerea is accompanied by decreased expression of JA-induced defense genes and reduced accumulation of JA-induced indole glucosinolates （IGs）. Conversely, the enhanced resistance to B. cinerea in CYP82C2-overexpressing plants is accompanied by increased expression of JA-induced defense genes and elevated levels of JA-induced IGs. We demonstrate that CYP82C2 affects JA-induced accumulation of the IG biosynthetic precursor tryptophan （Trp）, but not the JA-induced IAA or pathogen-induced camalexin. Together, our results support a hypothesis that CYP82C2 may act in the metabolism of Trp-derived secondary metabolites under conditions in which JA levels are elevated. Thejah1-1 mutant should thus be important in future studies toward understanding the mechanisms underlying the complexity of JA-mediated differential responses, which are important for plants to adapt their growth to the ever-changing environments.
文摘Messenger RNA （mRNA） turnover in eukaryotic cells begins with shortening of the poly （A） tail at the 3＇ end, a process called deadenylation. In yeast, the deadenylation reaction is predominantly mediated by CCR4 and CCR4- associated factor 1 （CAF1）, two components of the well-characterised protein complex named CCR4-NOT. We report here that AtCAF1a and AtCAF1b, putative Arabidopsis homologs of the yeast CAF1 gene, partially complement the growth defect of the yeast call mutant in the presence of caffeine or at high temperatures. The expression of At-CAF1a and AtCAFlb is induced by multiple stress-related hormones and stimuli. Both AtCAF1a and AtCAFlb show deadenylation activity in vitro and point mutations in the predicted active sites disrupt this activity. T-DNA insertion mutants disrupting the expression of AtCAF1a and/or AtCAF1b are defective in deadenylation of stress-related mRNAs, indicating that the two AtCAF1 proteins are involved in regulated mRNA deadenylation in vivo. Interestingly, the single and double mutants of AtCAF1a and AtCAFlb show reduced expression of pathogenesis-related （PR） genes PR1 and PR2 and are more susceptible to Pseudomonas syringae pv tomato DC3000 （Pst DC3000） infection, whereas transgenic plants over-expressing AtCAFla show elevated expression of PR1 and PR2 and increased resis-tance to the same pathogen. Our results suggest roles of the AtCAF1 proteins in regulated mRNA deadenylation and defence responses to pathogen infections.
文摘Decades of physiological and molecular studies have demonstrated that plants rely on a diverse set of small molecule hormones to regulate every aspect of their biological processes including development,growth and adaptation.
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the the National Basic Research Program (No. 2005CB120804) and Chinese Academy of Sciences.
文摘Drought is very harmful to grain yield due to its adverse effect on reproduction, especially on pollination process in rice. However, the molecular basis of such an effect still remains largely unknown. Here, we report the role of a member of CBL （Calcineurin B-Like） Interacting Protein Kinase （CIPK） family, OsCIPK23, in pollination and stress responses in rice. Molecular analyses revealed that it is mainly expressed in pistil and anther but up-regulated by pollination, as well as by treatments of various abiotic stresses and phytohormones. RNA interference-mediated suppression of OsCIPK23 expression significantly reduced seed set and conferred a hypersensitive response to drought stress, indicating its possible roles in pollination and drought stress. In consistent, overexpression of OsCIPK23 induced the expression of several drought tolerance related genes. Taken together, these results indicate that OsCIPK23 is a multistress induced gene and likely mediates a signaling pathway commonly shared by both pollination and drought stress responses in rice.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA08030105)Key Programs of the Chinese Academy of Sciences (KFZD-SW112)STS Project of Chinese Academy of Sciences (KFJ-STS-ZDTP-024)
文摘Xiaoyan 60(XY60) is a new wheat variety bred in the laboratory of Zhensheng Li.After salt treatment, seedlings of XY60 maintain green leaves and produce longer roots than the high yielding cultivar Zhongmai 175(ZM175).To explain these different phenotypes we carried out an RNA-Seq analysis using 12 samples from three tissues of both varieties subjected to salt and control treatments.By comparing data from the salt treated plants with the control, 703, 979, and 1197 differentially expressed genes(DEGs) were detected in new leaves, old leaves, and roots of XY60, respectively.The corresponding numbers for ZM175 were 613, 1401, and 1301.The most significantly enriched Gene Ontology(GO) terms and KEGG pathways were associated with polyunsaturated fatty acid(PUFA) metabolism in both new and old leaves from XY60.They were associated with photosynthesis and energy metabolism in ZM175.The most significantly enriched KEGG pathway in roots of both varieties was “glucosinolate biosynthesis”.In addition, jasmonic acid(JA) concentration in XY60 was higher than in ZM175, although it increased significantly in both varieties following salt treatment.Trends in relative expression levels of AOS, MYC2, and JAZ revealed by qRT-PCR were concordant with those from RNA-Seq.Our results suggest that PUFAs may contribute to salt tolerance in common wheat by enhancing the photosynthetic system and JA-related pathways.
基金supported with funds from the National Natural Science Foundation of China(30921003 and 30830063)the Chinese Academy of Sciences(KSCX2-YW-N-048)
文摘RNA helicases are adenosine tri-phosphatases that unwind the secondary structures of RNAs and are required in almost any aspect of RNA metabolism. They are highly conserved from prokaryotic to eukaryotic organisms. However, their precise roles in plant physiology and development remain to be clarified. Here we report that the mutation in the gene SLOW WALKER3 （SWA3） results in the slow and retarded progression of mitosis during megagametogenesis in Arabidopsis. SWA3 is a putative RNA helicase of the DEAD-box subfamily. Mutant megagametophyte development is arrested at fouror eight-nucleate stages, furthermore, one of the synergids in about half of the mutant embryo sacs displays abnormal polarity, with its nucleus locating at the chalazal end, instead of the micropylar end in the wild-type. Transmission of the mutation through female gametophytes is severely reduced in swa3. However, a small portion of mutant embryo sacs are able to develop into mature and functional female gametophytes when pollination was postponed. The SWA3 in Arabidopsis is a homolog of Dbp8 in yeast. Dbp8 interacts with Efs2 and is essential for biogenesis of 18S rRNA in yeast. Our data suggest that SWA3 may form a complex with AtEfs2 and take roles in ribosomal biogenesis as RNA helicase during megagametogenesis in Arabidopsis.
基金financially supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(grant no.XDA24040202)the CAS Key Technology Talent Program(2017,Y869041)the National Natural Science Foundation of China(grant nos.32270427 and 31800303).
文摘Dear Editor,Tomato systemin(TomSys),the first discovered plant peptide hormone,can initiate systemic mobile signals to stimulate an immune response in both wounded and intact leaves(Pearce et al.,1991).For decades,biologists have been striving to uncover the mechanisms of TomSys function,but detailed information on the TomSys-regulated systemic defense process remains limited to date.The specific roles of three potential transmissible signaling components,ProSys mRNA,TomSys,and jasmonic acid(JA),in activation of systemic defense responses still need to be clarified(Zhang et al.,2020).
基金financially supported by STI 2030-Major Projects(2023ZD0406802)the Crop Varietal Improvement and Insect Pests Control by Nuclear Radiation,the China Agriculture Research System of MOF and MARA(CARS-03)the Innovation Program of Chinese Academy of Agricultural Sciences。
文摘Dear Editor,The world faces unprecedented challenges for crop yield improvement to feed an expanding human population under limited agricultural resources and an increasingly erratic climate(Wheeler and von Braun,2013).Bread wheat is one of the most widely cultivated cereal crops,with both grain and flag leaf morphologies determining final yield potential(Xie et al.,2015;Zanella et al.,2023).Candidate genes affecting these traits are therefore highly desirable targets for breeding programs.
基金supported by the National Natural Science Foundation of China (90917017 and 90817008)
文摘Plant hormones are small molecular natural products that regulate all plant developmental processes at low concentrations. Quantitative analysis of plant hormones is increasingly important for in-depth study of their biosynthesis,transport,metabolism and molecular regulatory mechanisms. Although plant hormone analysis remains a bottleneck in plant scientific research owing to the trace concentrations and complex components in plant crude extracts,much progress has been achieved in the development of extraction,purification and detection techniques in recent years. Solid phase extraction and chromatography/mass spectrometry have been applied widely for purification and quantitative analysis of plant hormones owing to their high selectivity and sensitivity. Purification methods such as liquid partition and immunoaffinity chromatography,and detection methods including immunoassay and electrochemical analysis,are employed. The advantages and disadvantages of these methods are discussed. In situ,real-time and multi-plant hormone profiling will comprise mainstream techniques for quantitative analyses in future studies on the regulatory mechanisms and crosstalk of plant hormones.
文摘Pollen fertility is a crucial factor for successful pollination and essential for seed formation. Recent studies have suggested that a diverse range of internal and external factors, signaling components and their related pathways are likely involved in pollen fertility. Here, we report a single C2-domain containing protein, OsPBP1, initially identified through cDNA microarray analysis. OsPBP1 is a single copy gene and preferentially expressed in pistil and pollen but downregulated by pollination. OsPBP1 had a calcium concentration-dependent phospholipid-binding activity and was localized mainly in cytoplasm and nucleus, but translocated onto the plasma membrane in response to an intracellular Ca^2＋ increase. Pollen grains of antisense OsPBP1 transgenic lines were largely nonviable, germinated poorly in vitro and of low fertility. OsPBP1 protein was localized in a region peripheral to pollen wall and vesicles of elongating pollen tube, and its repressed expression reduced substantially this association and led to alteration of microfilament polymerization during pollen germination. Taken together, these results indicate that OsPBP1 is a novel functional C2-domain phospholipids-binding protein that is required for pollen fertility likely by regulating Ca^2＋ and phospholipid signaling pathways.
基金supported by the National Key Research and Development Program of China (2016YFD0100500 and 2016YFD0101703)the National Natural Science Foundation of China (Nos. 31601759 and 31471881)+1 种基金the Ministry of Agriculture of China (2016ZX08009-003-001)the Tai-Shan Scholar Program from the Shandong Provincial Government
文摘Tomato （Solanum lycopersicum） is the leading vegetable crop worldwide and an essential component of a healthy diet （Lin et al., 2014; Du et al., 2017）. Fruit color is regarded as one of the most important commercial traits in tomato （The Tomato Genome Consortium, 2012）. Consumers in different regions have different color preferences. For example, European and American consumers prefer red tomatoes, while pink tomatoes are more pop- ular in Asia countries, particularly in China and Japan （Ballester et al., 2010; Lin et al., 2014）. However, most of tomato breeding ma- terials are red-fruited, thus the generation of pink-fruited materials is very important for Asian tomato production. Metabolomics and genetics studies demonstrate that the pink trait results from the absence of yellow-colored flavonoid naringenin chalcone （NarCh） in the peels,
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences(grant no.XDA24040202)the National Natural Science Foundation of China(grant no.31770398,31470433,31500299)+1 种基金the Key Research Program of the Chinese Academy of Sciences(grant no.KFZD-SW-112)the CAS Key Technology Talent Program(2017).
文摘One of the hottest topics in plant hormone biology is the crosstalk mechanisms,whereby multiple classes of phytohormones interplay with each other through signaling networks.To better understand the roles of hormonal crosstalks in their complex regulatory networks,it is of high significance to investigate the spatial and temporal distributions of multiple-phytohormones simultaneously from one plant tissue sample.In this study,we develop a high-sensitivity and high-throughput method for the simultaneous quantitative analysis of 44 phytohormone compounds,covering currently known 10 major classes of phytohormones(strigolactones,brassinosteroids,gibberellins,auxin,abscisic acid,jasmonic acid,salicylic acid,cytokinins,ethylene,and polypeptide hormones[e.g.,phytosulfokine])from only 100 mg of plant sample.These compounds were grouped and purified separately with a tailored solid-phase extraction procedure based on their physicochemical properties and then analyzed by LC–MS/MS.The recoveries of our method ranged from 49.6%to 99.9%and the matrix effects from 61.8%to 102.5%,indicating that the overall sample pretreatment design resulted in good purification.The limits of quantitation(LOQs)of our method ranged from 0.06 to 1.29 pg/100 mg fresh weight and its precision was less than 13.4%,indicating high sensitivity and good reproducibility of the method.Tests of our method in different plant matrices demonstrated its wide applicability.Collectively,these advantages will make our method helpful in clarifying the crosstalk networks of phytohormones.
基金supported by National Natural Science Foundation of China(Grant No.31030047)the National Basic Research Program(973 Program)(No.2011CB915402).
文摘Detection of protein-protein interaction can provide valuable information for investigating the biological function of proteins.The current methods that applied in protein-protein interaction,such as co-immunoprecipitation and pull down etc.,often cause plenty of working time due to the burdensome cloning and puri-fication procedures.Here we established a system that characterization of protein-protein interaction was accomplished by co-expression and simply purification of target proteins from one expression cassette within E.coli system.We modified pET vector into co-expression vector pInvivo which encoded PPV NIa protease,two cleavage site F and two multiple cloning sites that flanking cleavage sites.The target proteins(for example:protein A and protein B)were inserted at multiple cloning sites and translated into polyprotein in the order of MBP tag-protein A-site F-PPV NIa protease-site F-protein B-His6 tag.PPV NIa protease carried out intracellular cleavage along expression,then led to the separation of polyprotein components,therefore,the interaction between protein A-protein B can be detected through one-step purification and analysis.Negative control for protein B was brought into this system for monitoring interaction specificity.We successfully employed this system to prove two cases of reported protien-protein interaction:RHA2a/ANAC and FTA/FTB.In conclusion,a convenient and efficient system has been successfully developed for detecting protein-protein interaction.
文摘Plants rely on a diverse set of small-molecule hormones to regu- late every aspect of their biological processes including develop- ment, growth, and adaptation. Since the discovery of the first plant hormone, auxin, hormones have always been at the frontier of plant biology.
基金This work was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences,China(XDA24020308)the National Key Research and Development Program of China,China(2016YFD0100500)+1 种基金the Ministry of Agriculture of China,China(2016ZX08009-003-001)he Tai-Shan Scholar Program from Shandong Province(No.tsxk20150901).
文摘Dietary anthocyanins are important health-promoting antioxidants that make a major contribution to the quality of fruits. It is intriguing that most tomato cultivars do not produce anthocyanins in fruit. However, the purple tomato variety Indigo Rose, which has the dominant Aft locus combined with the recessive atv locus from wild tomato species, exhibits light-dependent anthocyanin accumulation in the fruit skin. Here, we report that Aft encodes a functional anthocyanin activator named SlAN2-like, while atv encodes a nonfunctional version of the anthocyanin repressor SlMYBATV. The expression of SlAN2-like is responsive to light, and the functional SlAN2-like can activate the expression of both anthocyanin biosynthetic genes and their regulatory genes, suggesting that SlAN2-like acts as a master regulator in the activation of anthocyanin biosynthesis. We further showed that cultivated tomatoes contain nonfunctional alleles of SlAN2-like and therefore fail to produce anthocyanins. Consistently, expression of a functional SlAN2-like gene driven by the fruit-specific promoter in a tomato cultivar led to the activation of the entire anthocyanin biosynthesis pathway and high-level accumulation of anthocyanins in both the peel and flesh. Taken together, our study exemplifies that efficient engineering of complex metabolic pathways could be achieved through tissue-specific expression of master transcriptional regulators.
基金This work was supported by grants from the National Basic Research Program of China （2016YFD0100402 2016YFD0100501+6 种基金 2017YFD0101701 2013CBA01401）, the National Natural Science Foundation of China （91735302 31771340 31500976 91535203 31425004 31400249）, the Chinese Academy of Sciences （XDA08020108）, the Ministry of Agriculture of China （2014ZX08009-003）, and the strategic pdodty research program ＂Molecular Mechanism of Plant Growth and Development＂ （XDBP401）.
文摘Grain size is one of the key agronomic traits that determine grain yield in crops. However, the mechanisms underlying grain size control in crops remain elusive. Here we demonstrate that the OsMKKK10-OsMKK4- OsMAPK6 signaling pathway positively regulates grain size and weight in rice. In rice, loss of OsMKKKIO function results in small and light grains, short panicles, and semi-dwarf plants, while overexpression of constitutively active OsMKKK10 （CA-OsMKKK10） results in large and heavy grains, long panicles, and tall plants. OsMKKK10 interacts with and phosphorylates OsMKK4. We identified an OsMKK4 gain-of-func- tion mutant （large11-1D）that produces large and heavy grains. OsMKK4A227T encoded by the large11-1D allele has stronger kinase activity than OsMKK4. Plants overexpressing a constitutively active form of OsMKK4 （OsMKK4oDD） also produce large grains. Further biochemical and genetic analyses revealed that OsMKKK10, OsMKK4, and OsMAPK6 function in a common pathway to control grain size. Taken together, our study establishes an important genetic and molecular framework for OsMKKK10-OsMKK4- OsMAPK6 cascade-mediated control of grain size and weight in rice.
文摘Wound-inducible proteinase inhibitors （PIs） in tomato plants provide a useful model system to elucidate the signal transduction pathways that regulate systemic defense response. Among the proposed intercellular signals for wound-induced PIs expression are the peptide systemin and the oxylipin-derived phytohormone jasmonic acid （JA）. An increasing body of evidence indicates that systemin and JA work in the same signaling pathway to activate the ex- pression of PIs and other defense-related genes. However, relatively less is known about how these signals interact to promote cell-to-cell communication over long distances. Genetic analysis of the systemin/JA signaling pathway in tomato plants provides a unique opportunity to study, in a single experimental system, the mechanism by which peptide and oxylipin signals interact to coordinate systemic expression of defense-related genes. Previously, it has been proposed that systemin is the long-distance mobile signal for defense gene expression. Recently, grafting experiments with tomato mutants defective in JA biosynthesis and signaling provide new evidence that JA, rather than systemin, functions as the systemic wound signal, and that the biosynthesis of JA is regulated by the peptide systemin. Further understanding of the systemin/JA signaling pathway promises to provide new insights into the basic mechanisms governing plant defense to biotic stress.
基金supported by the National Basic Research Program of China (Grant No. 2006CB100102)National High-Tech Project (Grant No. 2006AA10Z18201)
文摘Tocopherols synthesized exclusively by photosynthetic organisms are major antioxidants in biomembranes.In plants,tocopherol cyclase(TC/VTE1) catalyzes the conversion of 2,3-dimethyl-5-phytyl-1,4-benzoquinone(DMPBQ) to γ-tocopherol.In the present study,OsVTE1,which encodes a rice tocopherol cyclase ortholog,was cloned and characterized.OsVTE1 was induced significantly by abiotic stresses such as high salt,H2O2,drought,cold and by the plant hormones ABA and salicylic acid.The tissue-specific expression pattern and OsVTE1-promoter GUS activity assay showed that OsVTE1 was mainly expressed in the leaf,and also could be detected in the root,stem and panicle.Compared with control plants,transgenic plants with OsVTE1 RNA interference(OsVTE1-RNAi) were more sensitive to salt stress whereas,in contrast,transgenic plants overexpressing OsVTE1(OsVTE1-OX) showed higher tolerance to salt stress.The DAB in vivo staining showed that OsVTE1-OX plants accumulated less H2O2 than did control plants.
基金supported by the National Key Research and Development Program of China (2017YFD0101900)the National Natural Science Foundation of China(31601759)+1 种基金the Key Research and Development Program of Guangdong Province (2018B020202006)the Ministry of Agriculture of China (2016ZX08009-003-001)
文摘As one of the most important vegetables,tomato (Solanum lycopersicum) is extensively produced and consumed worldwide and substantially contributes to human nutrition and health (The Tomato Genome Consortium,2012).Although red tomatoes are the most common,pink tomatoes are more popular in Asia,particularly in China and Japan,because of their better taste (Ballester et al.,2010;Zhu et al.,2018).Compared with red tomatoes,pink tomatoes fail to accumulate the yellow-colored flavonoid pigment,naringenin chalcone (NarCh),in their peels,resulting in a colorless peel phenotype (Adato et al,2009;Ballester et al.,2010).
