Salt stress and flowering time are major factors limiting geographic adaptation and yield productivity in soybean(Glycine max).Although improving crop salt tolerance and latitude adaptation are essential for efficient...Salt stress and flowering time are major factors limiting geographic adaptation and yield productivity in soybean(Glycine max).Although improving crop salt tolerance and latitude adaptation are essential for efficient agricultural production,whether and how these two traits are integrated remains largely unknown.Here,we used a genome-wide association study to identify a major salt-tolerance locus controlled by E2,an ortholog of Arabidopsis thaliana GIGANTEA(GI).Loss of E2 function not only shortened flowering time and maturity,but also enhanced salt-tolerance in soybean.E2 delayed soybean flowering by enhancing the transcription of the core flowering suppressor gene E1,thereby repressing Flowering Locus T(FT)expression.An E2 knockout mutant e2^(CR) displayed reduced accumulation of reactive oxygen species(ROS)during the response to salt stress by releasing peroxidase,which functions in ROS scavenging to avoid cytotoxicity.Evolutionary and population genetic analyses also suggested that loss-of-function e2 alleles have been artificially selected during breeding for soybean adaptation to high-latitude regions with greater salt stress.Our findings provide insights into the coupled selection for adaptation to both latitude and salt stress in soybean;and offer an ideal target for molecular breeding of early-maturing and salt-tolerant cultivars.展开更多
Soybean(Glycine max L.)is a typical photoperiodsensitive crop,such that photoperiod determines its flowering time,maturity,grain yield,and phenological adaptability.During evolution,the soybean genome has undergone tw...Soybean(Glycine max L.)is a typical photoperiodsensitive crop,such that photoperiod determines its flowering time,maturity,grain yield,and phenological adaptability.During evolution,the soybean genome has undergone two duplication events,resulting in about 75%of all genes being represented by multiple copies,which is associated with rampant gene redundancy.Among duplicated genes,the important soybean maturity gene E2 has two homologs,E2-Like a(E2La)and E2-Like b(E2Lb),which encode orthologs of Arabidopsis GIGANTEA(GI).Although E2 was cloned a decade ago,we still know very little about its contribution to flowering time and even less about the function of its homologs.Here,we generated single and double mutants in E2,E2La,and E2Lb by genome editing and determined that E2 plays major roles in the regulation of flowering time and yield,with the two E2 homologs depending on E2 function.At high latitude regions,e2 single mutants showed earlier flowering and high grain yield.Remarkably,in terms of genetic relationship,genes from the legume-specific transcription factor family E1 were epistatic to E2.We established that E2 and E2-like proteins form homodimers or heterodimers to regulate the transcription of E1 family genes,with the homodimer exerting a greater function than the heterodimers.In addition,we established that the H3 haplotype of E2 is the ancestral allele and is mainly restricted to low latitude regions,from which the loss-of-function alleles of the H1 and H2haplotypes were derived.Furthermore,we demonstrated that the function of the H3 allele is stronger than that of the H1 haplotype in the regulation of flowering time,which has not been shown before.Our findings provide excellent allelic combinations for classical breeding and targeted gene disruption or editing.展开更多
基金supported by the Major Program of Guangdong Basic and Applied Research (Grant no. 2019B030302006 to F.K. and B.L.)supported by the National Natural Science Foundation of China (Grant no. 32090064 to F.K., 31930083 to B.L.)supported by Science and Technology Planning Project of Guangzhou (Grant no. 202102010388 to L.D., 202102010389 to Q.C.)
文摘Salt stress and flowering time are major factors limiting geographic adaptation and yield productivity in soybean(Glycine max).Although improving crop salt tolerance and latitude adaptation are essential for efficient agricultural production,whether and how these two traits are integrated remains largely unknown.Here,we used a genome-wide association study to identify a major salt-tolerance locus controlled by E2,an ortholog of Arabidopsis thaliana GIGANTEA(GI).Loss of E2 function not only shortened flowering time and maturity,but also enhanced salt-tolerance in soybean.E2 delayed soybean flowering by enhancing the transcription of the core flowering suppressor gene E1,thereby repressing Flowering Locus T(FT)expression.An E2 knockout mutant e2^(CR) displayed reduced accumulation of reactive oxygen species(ROS)during the response to salt stress by releasing peroxidase,which functions in ROS scavenging to avoid cytotoxicity.Evolutionary and population genetic analyses also suggested that loss-of-function e2 alleles have been artificially selected during breeding for soybean adaptation to high-latitude regions with greater salt stress.Our findings provide insights into the coupled selection for adaptation to both latitude and salt stress in soybean;and offer an ideal target for molecular breeding of early-maturing and salt-tolerant cultivars.
基金funded by the National Natural Science Foundation of China (Grant No.32072013,31801383 to X.Z.)the National Key Research and Development Program (Grant no.2021YFF1001203 to X.Z.)。
文摘Soybean(Glycine max L.)is a typical photoperiodsensitive crop,such that photoperiod determines its flowering time,maturity,grain yield,and phenological adaptability.During evolution,the soybean genome has undergone two duplication events,resulting in about 75%of all genes being represented by multiple copies,which is associated with rampant gene redundancy.Among duplicated genes,the important soybean maturity gene E2 has two homologs,E2-Like a(E2La)and E2-Like b(E2Lb),which encode orthologs of Arabidopsis GIGANTEA(GI).Although E2 was cloned a decade ago,we still know very little about its contribution to flowering time and even less about the function of its homologs.Here,we generated single and double mutants in E2,E2La,and E2Lb by genome editing and determined that E2 plays major roles in the regulation of flowering time and yield,with the two E2 homologs depending on E2 function.At high latitude regions,e2 single mutants showed earlier flowering and high grain yield.Remarkably,in terms of genetic relationship,genes from the legume-specific transcription factor family E1 were epistatic to E2.We established that E2 and E2-like proteins form homodimers or heterodimers to regulate the transcription of E1 family genes,with the homodimer exerting a greater function than the heterodimers.In addition,we established that the H3 haplotype of E2 is the ancestral allele and is mainly restricted to low latitude regions,from which the loss-of-function alleles of the H1 and H2haplotypes were derived.Furthermore,we demonstrated that the function of the H3 allele is stronger than that of the H1 haplotype in the regulation of flowering time,which has not been shown before.Our findings provide excellent allelic combinations for classical breeding and targeted gene disruption or editing.
