Plants under pathogen attack produce high levels of the gaseous phytohormone ethylene to induce plant defense responses via the ethylene signaling pathway.The 1-aminocyclopropane-1-carboxylate synthase(ACS)is a critic...Plants under pathogen attack produce high levels of the gaseous phytohormone ethylene to induce plant defense responses via the ethylene signaling pathway.The 1-aminocyclopropane-1-carboxylate synthase(ACS)is a critical rate-limiting enzyme of ethylene biosynthesis.Transcriptional and post-translational upregulation of ACS2 and ACS6 by the mitogen-activated protein kinases MPK3 and MPK6 are previously shown to be crucial for pathogen-induced ethylene biosynthesis in Arabidopsis.Here,we report that the fungal pathogen Botrytis cinerea-induced ethylene biosynthesis in Arabidopsis is under the negative feedback regulation by ethylene signaling pathway.The ethylene response factor ERF1 A is further found to act downstream of ethylene signaling to negatively regulate the B.cinerea-induced ethylene biosynthesis via indirectly suppressing the expression of ACS2 and ACS6.Interestingly,ERF1 A is shown to also upregulate defensin genes directly and therefore promote Arabidopsis resistance to B.cinerea.Furthermore,ERF1 A is identified to be a substrate of MPK3 and MPK6,which phosphoactivate ERF1 A to enhance its functions in suppressing ethylene biosynthesis and inducing defensin gene expression.Taken together,our data reveal that ERF1 A and its phosphorylation by MPK3/MPK6 not only mediate the negativefeedback regulation of the B.cinerea-induced ethylene biosynthesis,but also upregulate defensin gene expression to increase Arabidopsis resistance to B.cinerea.展开更多
Dehydrin(DHN)enhances plant resistance to environmental stress by regulating the synthesis of osmotic adjustment substances and scavenging reactive oxygen species.However,the role of PbDHN3 under salt stress remains u...Dehydrin(DHN)enhances plant resistance to environmental stress by regulating the synthesis of osmotic adjustment substances and scavenging reactive oxygen species.However,the role of PbDHN3 under salt stress remains unclear.In this study,salt stress induced high expression of PbDHN3,and the overexpression of PbDHN3(OE-PbDHN3)enhanced plant growth under salt stress compared to wild-type(WT)plants.OE-PbDHN3 plants exhibited higher chlorophyll content and root growth capacity than WT plants under salt stress.Transcriptome analysis revealed that PbDHN3 expression is associated with ethylene signaling pathways.OE-PbDHN3 transgenic plants substantially influenced ethylene content and the expression of related genes.Following treatment with exogenous ethephon,the transgenic lines notably inhibited the processes of ethylene synthesis and signaling transduction.OE-PbDHN3 transgenic lines treated with exogenous ethylene and the ethylene inhibitor 1-MCP demonstrated significant inhibition of ethylene synthesis and signaling transduction,while promoting root development and chlorophyll content.Under salt stress,OE-PbDHN3 downregulated the expression of ethylene biosynthesis genes PbACO1-like and PbACO2,and signal transduction genes PbEIN3-like during the initial stress phase.This early regulation mitigated the adverse effects of salt stress on the plants.These findings demonstrate that PbDHN3 ameliorates the ethylene-mediated plant growth phenotype under salt stress through regulation of ethylene synthesis and signal transduction.展开更多
Increasing evidence has revealed that abscisic acid （ABA） negatively modulates ethylene biosynthesis, although the underlying mechanism remains unclear. To identify the factors involved, we conducted a screen for AB...Increasing evidence has revealed that abscisic acid （ABA） negatively modulates ethylene biosynthesis, although the underlying mechanism remains unclear. To identify the factors involved, we conducted a screen for ABA-insensitive mutants with altered ethylene production in Arabidopsis. A dominant allele of ABI4, abi4-152, which produces a putative protein with a 16-amino-acid truncation at the C-terminus of ABI4, reduces ethylene production. By contrast, two recessive knockout alleles of ABI4, abi4-102 and abi4-103, result in increased ethylene evolution, indicating that ABI4 negatively regulates ethylene produc- tion. Further analyses showed that expression of the ethylene biosynthesis genes ACS4, ACSS, and AC02 was significantly decreased in abi4-152 but increased in the knockout mutants, with partial dependence on ABA. Chromatin immunoprecipitation-quantitative PCR assays showed that ABI4 directly binds the pro- moters of these ethylene biosynthesis genes and that ABA enhances this interaction. A fusion protein containing the truncated ABI4-152 peptide accumulated to higher levels than its full-length counterpart in transgenic plants, suggesting that ABI4 is destabilized by its C terminus. Therefore, our results demon- strate that ABA negatively regulates ethylene production through ABI4-mediated transcriptional repression of the ethylene biosynthesis genes ACS4 and ACS8 in Arabidopsis.展开更多
Soybean[Glycine max(L.)Merr.]is one of the most important,but a drought-sensitive,crops.Identifying the genes controlling drought tolerance is important in soybean breeding.Here,through a genome-wide association study...Soybean[Glycine max(L.)Merr.]is one of the most important,but a drought-sensitive,crops.Identifying the genes controlling drought tolerance is important in soybean breeding.Here,through a genome-wide association study,we identified one significant association locus,located on chromosome 8,which conferred drought tolerance variations in a natural soybean population.Allelic analysis and genetic validation demonstrated that GmACO1,encoding for a 1-aminocyclopropane-1-carboxylate oxidase,was the causal gene in this association locus,and positively regulated drought tolerance in soybean.Meanwhile,we determined that GmACO1 expression was reduced after rhizobial infection,and that GmACO1 negatively regulated soybean nodule formation.Overall,our findings provide insights into soybean cultivars for future breeding.展开更多
Seed size critically affects grain yield of crops and hence represents a key breeding target.The develop-ment of embryo-nourishing endosperm is a key driver of seed expansion.We here report unexpected dual roles of th...Seed size critically affects grain yield of crops and hence represents a key breeding target.The develop-ment of embryo-nourishing endosperm is a key driver of seed expansion.We here report unexpected dual roles of the transcription factor EIN3 in regulating seed size.These EIN3 functions have remained largely undiscovered because they oppose each other.Capitalizing on the analysis of multiple ethylene biosynthesis mutants,we demonstrate that EIN3 represses endosperm and seed development in a pathway regulated by ethylene.We,in addition,provide evidence that EIN3-mediated synergid nucleus disintegration promotes endosperm expansion.Interestingly,synergid nucleus disintegration is not affected in various ethylene biosynthesis mutants,suggesting that this promoting function of EIN3 is inde-pendent of ethylene.Whereas the growth-inhibitory ethylene-dependent EIN3 action appears to be encoded by sporophytic tissue,the growth-promoting role of EIN3 is induced by fertilization,revealing a generation conflict that converges toward the key signaling component EIN3.展开更多
基金supported by the National Natural Science Foundation of China (Grants 31970282 and 32170286 to X.M.)
文摘Plants under pathogen attack produce high levels of the gaseous phytohormone ethylene to induce plant defense responses via the ethylene signaling pathway.The 1-aminocyclopropane-1-carboxylate synthase(ACS)is a critical rate-limiting enzyme of ethylene biosynthesis.Transcriptional and post-translational upregulation of ACS2 and ACS6 by the mitogen-activated protein kinases MPK3 and MPK6 are previously shown to be crucial for pathogen-induced ethylene biosynthesis in Arabidopsis.Here,we report that the fungal pathogen Botrytis cinerea-induced ethylene biosynthesis in Arabidopsis is under the negative feedback regulation by ethylene signaling pathway.The ethylene response factor ERF1 A is further found to act downstream of ethylene signaling to negatively regulate the B.cinerea-induced ethylene biosynthesis via indirectly suppressing the expression of ACS2 and ACS6.Interestingly,ERF1 A is shown to also upregulate defensin genes directly and therefore promote Arabidopsis resistance to B.cinerea.Furthermore,ERF1 A is identified to be a substrate of MPK3 and MPK6,which phosphoactivate ERF1 A to enhance its functions in suppressing ethylene biosynthesis and inducing defensin gene expression.Taken together,our data reveal that ERF1 A and its phosphorylation by MPK3/MPK6 not only mediate the negativefeedback regulation of the B.cinerea-induced ethylene biosynthesis,but also upregulate defensin gene expression to increase Arabidopsis resistance to B.cinerea.
基金funded by the Earmarked Fund for CARS(CARS-28-07)the Agricultural Variety Improvement Project of Shandong Province,China(2022LZGC011)the Qingdao Agricultural University Doctoral Start-Up Fund,China.
文摘Dehydrin(DHN)enhances plant resistance to environmental stress by regulating the synthesis of osmotic adjustment substances and scavenging reactive oxygen species.However,the role of PbDHN3 under salt stress remains unclear.In this study,salt stress induced high expression of PbDHN3,and the overexpression of PbDHN3(OE-PbDHN3)enhanced plant growth under salt stress compared to wild-type(WT)plants.OE-PbDHN3 plants exhibited higher chlorophyll content and root growth capacity than WT plants under salt stress.Transcriptome analysis revealed that PbDHN3 expression is associated with ethylene signaling pathways.OE-PbDHN3 transgenic plants substantially influenced ethylene content and the expression of related genes.Following treatment with exogenous ethephon,the transgenic lines notably inhibited the processes of ethylene synthesis and signaling transduction.OE-PbDHN3 transgenic lines treated with exogenous ethylene and the ethylene inhibitor 1-MCP demonstrated significant inhibition of ethylene synthesis and signaling transduction,while promoting root development and chlorophyll content.Under salt stress,OE-PbDHN3 downregulated the expression of ethylene biosynthesis genes PbACO1-like and PbACO2,and signal transduction genes PbEIN3-like during the initial stress phase.This early regulation mitigated the adverse effects of salt stress on the plants.These findings demonstrate that PbDHN3 ameliorates the ethylene-mediated plant growth phenotype under salt stress through regulation of ethylene synthesis and signal transduction.
文摘Increasing evidence has revealed that abscisic acid （ABA） negatively modulates ethylene biosynthesis, although the underlying mechanism remains unclear. To identify the factors involved, we conducted a screen for ABA-insensitive mutants with altered ethylene production in Arabidopsis. A dominant allele of ABI4, abi4-152, which produces a putative protein with a 16-amino-acid truncation at the C-terminus of ABI4, reduces ethylene production. By contrast, two recessive knockout alleles of ABI4, abi4-102 and abi4-103, result in increased ethylene evolution, indicating that ABI4 negatively regulates ethylene produc- tion. Further analyses showed that expression of the ethylene biosynthesis genes ACS4, ACSS, and AC02 was significantly decreased in abi4-152 but increased in the knockout mutants, with partial dependence on ABA. Chromatin immunoprecipitation-quantitative PCR assays showed that ABI4 directly binds the pro- moters of these ethylene biosynthesis genes and that ABA enhances this interaction. A fusion protein containing the truncated ABI4-152 peptide accumulated to higher levels than its full-length counterpart in transgenic plants, suggesting that ABI4 is destabilized by its C terminus. Therefore, our results demon- strate that ABA negatively regulates ethylene production through ABI4-mediated transcriptional repression of the ethylene biosynthesis genes ACS4 and ACS8 in Arabidopsis.
基金supported by the National Key Research and Development Program of China(2022YFD1201503)the National Natural Science Foundation of China(32341033,U22A20467)+1 种基金the Taishan Scholars Program,Hainan Seed Industry Laboratory(B21HJ0002,B23YQ1502)The GG project of the Xinjiang Production and Construction Corps,Provincial Special Fund for Science and Technology Innovation and Development of Agricultural Hightech Industrial Demonstration Area of the Yellow River Delta of Shandong Province(2022SZX15).
文摘Soybean[Glycine max(L.)Merr.]is one of the most important,but a drought-sensitive,crops.Identifying the genes controlling drought tolerance is important in soybean breeding.Here,through a genome-wide association study,we identified one significant association locus,located on chromosome 8,which conferred drought tolerance variations in a natural soybean population.Allelic analysis and genetic validation demonstrated that GmACO1,encoding for a 1-aminocyclopropane-1-carboxylate oxidase,was the causal gene in this association locus,and positively regulated drought tolerance in soybean.Meanwhile,we determined that GmACO1 expression was reduced after rhizobial infection,and that GmACO1 negatively regulated soybean nodule formation.Overall,our findings provide insights into soybean cultivars for future breeding.
基金support from tho Europoan Rosearch Council to R.G.(ERC Consolidator Grant"bi-BL OCK"ID 646644,ERC Proof of Concept Grant"TnVolve"ID 957547).
文摘Seed size critically affects grain yield of crops and hence represents a key breeding target.The develop-ment of embryo-nourishing endosperm is a key driver of seed expansion.We here report unexpected dual roles of the transcription factor EIN3 in regulating seed size.These EIN3 functions have remained largely undiscovered because they oppose each other.Capitalizing on the analysis of multiple ethylene biosynthesis mutants,we demonstrate that EIN3 represses endosperm and seed development in a pathway regulated by ethylene.We,in addition,provide evidence that EIN3-mediated synergid nucleus disintegration promotes endosperm expansion.Interestingly,synergid nucleus disintegration is not affected in various ethylene biosynthesis mutants,suggesting that this promoting function of EIN3 is inde-pendent of ethylene.Whereas the growth-inhibitory ethylene-dependent EIN3 action appears to be encoded by sporophytic tissue,the growth-promoting role of EIN3 is induced by fertilization,revealing a generation conflict that converges toward the key signaling component EIN3.
