Low-temperature(LT)stress threatens cucumber production globally;however,the molecular mechanisms underlying LT tolerance in cucumber remain largely unknown.Here,using a genome-wide association study(GWAS),we found a ...Low-temperature(LT)stress threatens cucumber production globally;however,the molecular mechanisms underlying LT tolerance in cucumber remain largely unknown.Here,using a genome-wide association study(GWAS),we found a naturally occurring single nucleotide polymorphism(SNP)in the STAYGREEN(CsSGR)coding region at the gLTT5.1 locus associated with LT tolerance.Knockout mutants of CsSGR generated by clustered regularly interspaced palindromic repeats(CRISPR)/CRISPR-associated nuclease 9 exhibit enhanced LT tolerance,in particularly,increased chlorophyll(Chl)content and reduced reactive oxygen species(ROS)accumulation in response to LT.Moreover,the C-repeat Binding Factor 1(CsCBF1)transcription factor can directly activate the expression of CsSGR.We demonstrate that the LT-sensitive haplotype CsSGRHapA,but not the LT-tolerant haplotype CsSGR^(HapG)could interact with NON-YELLOW COLORING 1(CsNYC1)to mediate Chl degradation.Geographic distribution of the CsSGR haplotypes indicated that the CsSGR^(HapG)was selected in cucumber accessions from high latitudes,potentially contributing to LT tolerance during cucumber cold-adaptation in these regions.CsSGR mutants also showed enhanced tolerance to salinity,water deficit,and Pseudoperonospora cubensis,thus CsSGR is an elite target gene for breeding cucumber varieties with broad-spectrum stress tolerance.Collectively,our findings provide new insights into LT tolerance and will ultimately facilitate cucumber molecular breeding.展开更多
基金supported by the National Natural Science Foundation of China (No. 32372704)Key-Area Research and Development Program of Guangdong Province (2020B020220001)+2 种基金Beijing Joint Research Program for Germplasm Innovation and New Variety Breeding (G20220628003-03)the Earmarked Fund for Modern Agroindustry Technology Research System (CARS-23)Science and Technology Innovation Program of the Chinese Academy of Agricultural Science (CAAS-ASTIP-IVFCAAS)
文摘Low-temperature(LT)stress threatens cucumber production globally;however,the molecular mechanisms underlying LT tolerance in cucumber remain largely unknown.Here,using a genome-wide association study(GWAS),we found a naturally occurring single nucleotide polymorphism(SNP)in the STAYGREEN(CsSGR)coding region at the gLTT5.1 locus associated with LT tolerance.Knockout mutants of CsSGR generated by clustered regularly interspaced palindromic repeats(CRISPR)/CRISPR-associated nuclease 9 exhibit enhanced LT tolerance,in particularly,increased chlorophyll(Chl)content and reduced reactive oxygen species(ROS)accumulation in response to LT.Moreover,the C-repeat Binding Factor 1(CsCBF1)transcription factor can directly activate the expression of CsSGR.We demonstrate that the LT-sensitive haplotype CsSGRHapA,but not the LT-tolerant haplotype CsSGR^(HapG)could interact with NON-YELLOW COLORING 1(CsNYC1)to mediate Chl degradation.Geographic distribution of the CsSGR haplotypes indicated that the CsSGR^(HapG)was selected in cucumber accessions from high latitudes,potentially contributing to LT tolerance during cucumber cold-adaptation in these regions.CsSGR mutants also showed enhanced tolerance to salinity,water deficit,and Pseudoperonospora cubensis,thus CsSGR is an elite target gene for breeding cucumber varieties with broad-spectrum stress tolerance.Collectively,our findings provide new insights into LT tolerance and will ultimately facilitate cucumber molecular breeding.
