Flowering time is an important agronomic trait for soybean yield and adaptation. However, the genetic basis of soybean adaptation to diverse latitudes is still not clear. Four NIGHT LIGHT-INDUCIBLE AND CLOCK-REGULATED...Flowering time is an important agronomic trait for soybean yield and adaptation. However, the genetic basis of soybean adaptation to diverse latitudes is still not clear. Four NIGHT LIGHT-INDUCIBLE AND CLOCK-REGULATED 2(LNK2) homeologs of Arabidopsis thaliana LNK2 were identified in soybean. Three single-guide RNAs were designed for editing the four LNK2 genes. A transgene-free homozygous quadruple mutant of the LNK2 genes was developed using the CRISPR(clustered regularly interspaced short palindromic repeats)/Cas9(CRISPR-associated protein 9). Under long-day(LD) conditions, the quadruple mutant flowered significantly earlier than the wild-type(WT). Quantitative real-time PCR(q RT-PCR)revealed that transcript levels of LNK2 were significantly lower in the quadruple mutant than in the WT under LD conditions. LNK2 promoted the expression of the legume-specific E1 gene and repressed the expression of FT2 a. Genetic markers were developed to identify LNK2 mutants for soybean breeding.These results indicate that CRISPR/Cas9-mediated targeted mutagenesis of four LNK2 genes shortens flowering time in soybean. Our findings identify novel components in flowering-time control in soybean and may be beneficial for further soybean breeding in high-latitude environments.展开更多
Photoperiod responsiveness is a key factor limiting the geographic distribution of cultivated soybean and its wild ancestor.In particular,the genetic basis of the adaptation in wild soybean remains poorly understood.I...Photoperiod responsiveness is a key factor limiting the geographic distribution of cultivated soybean and its wild ancestor.In particular,the genetic basis of the adaptation in wild soybean remains poorly understood.In this study,by combining whole-genome resequencing and genome-wide association studies we identified a novel locus,Time of Flowering 5(Tof5),which promotes flowering and enhances adaptation to high latitudes in both wild and cultivated soybean.By genomic,genetic and transgenic analyses we showed that Tof5 en-codes a homolog of Arabidopsis thaliana FRUITFULL(FUL).Importantly,further analyses suggested that different alleles of Tof5 have undergone parallel selection.The Tof5H1 allele was strongly selected by humans after the early domestication of cultivated soybean,while Tof5H2 allele was naturally selected in wild soybean,and in each case facilitating adaptation to high latitudes.Moreover,we found that the key flowering repressor E1 suppresses the transcription of Tof5 by binding to its promoter.In turn,Tof5 physically associates with the promoters of two important FLOWERING LOCUS T(FT),FT2a and FT5a,to upregulate their transcription and promote flowering under long photoperiods.Collectively,ourfindings provide insights into how wild soybean adapted to high latitudes through natural selection and indicate that cultivated soybean underwent changes in the same gene but evolved a distinct allele that was artificially selected after domestication.展开更多
基金supported by National Key Research and Development Program of China(2017YFD0101305)the National Natural Science Foundation of China(31930083,31901568,31801384,31725021,and 31771815)。
文摘Flowering time is an important agronomic trait for soybean yield and adaptation. However, the genetic basis of soybean adaptation to diverse latitudes is still not clear. Four NIGHT LIGHT-INDUCIBLE AND CLOCK-REGULATED 2(LNK2) homeologs of Arabidopsis thaliana LNK2 were identified in soybean. Three single-guide RNAs were designed for editing the four LNK2 genes. A transgene-free homozygous quadruple mutant of the LNK2 genes was developed using the CRISPR(clustered regularly interspaced short palindromic repeats)/Cas9(CRISPR-associated protein 9). Under long-day(LD) conditions, the quadruple mutant flowered significantly earlier than the wild-type(WT). Quantitative real-time PCR(q RT-PCR)revealed that transcript levels of LNK2 were significantly lower in the quadruple mutant than in the WT under LD conditions. LNK2 promoted the expression of the legume-specific E1 gene and repressed the expression of FT2 a. Genetic markers were developed to identify LNK2 mutants for soybean breeding.These results indicate that CRISPR/Cas9-mediated targeted mutagenesis of four LNK2 genes shortens flowering time in soybean. Our findings identify novel components in flowering-time control in soybean and may be beneficial for further soybean breeding in high-latitude environments.
基金supported by the National Natural Science Foundation of China(grant nos.32090065 and 32001508 to L.D.,32090064 and 31725021 to F.K.,31930083 to B.L,31901568 to Q.C,32022062 to S.Lu.,32001502 to Y,Z)and also supported by the Major Program of Guangdong Basic and Applied FResearch(grant no.2019B030302006 to F.K.andB.L).
文摘Photoperiod responsiveness is a key factor limiting the geographic distribution of cultivated soybean and its wild ancestor.In particular,the genetic basis of the adaptation in wild soybean remains poorly understood.In this study,by combining whole-genome resequencing and genome-wide association studies we identified a novel locus,Time of Flowering 5(Tof5),which promotes flowering and enhances adaptation to high latitudes in both wild and cultivated soybean.By genomic,genetic and transgenic analyses we showed that Tof5 en-codes a homolog of Arabidopsis thaliana FRUITFULL(FUL).Importantly,further analyses suggested that different alleles of Tof5 have undergone parallel selection.The Tof5H1 allele was strongly selected by humans after the early domestication of cultivated soybean,while Tof5H2 allele was naturally selected in wild soybean,and in each case facilitating adaptation to high latitudes.Moreover,we found that the key flowering repressor E1 suppresses the transcription of Tof5 by binding to its promoter.In turn,Tof5 physically associates with the promoters of two important FLOWERING LOCUS T(FT),FT2a and FT5a,to upregulate their transcription and promote flowering under long photoperiods.Collectively,ourfindings provide insights into how wild soybean adapted to high latitudes through natural selection and indicate that cultivated soybean underwent changes in the same gene but evolved a distinct allele that was artificially selected after domestication.