Map-based cloning of a recessive gene v1 for virescent leaf expression in cotton (Gossypium spp.)

Abstract

Background: Virescence, as a recognizable phenotype in the early development stage of cotton, is not only available for research on chloroplast development and photosynthesis but also for heterosis exploitation in cotton. Methods: In current study, for fine mapping of virescent-1 (v 1 ) in cotton, three populations with a total of 5 678 individuals were constructed using T582 which has the virescent trait. Tobacco rattle virus, TRV1 and TRV2 (pYL156), were used as vectors for the virus-induced gene silencing (VIGS) assay. Results:The v 1 gene was fine-mapped to a 20 kb interval on chromosome 20 of tetraploid cotton. We identified only one candidate gene with four single nucleotide polymorphisms between parents, among which the single nucleotide polymorphism at the position of 1 082 base pair caused the change of amino acid residue from Arg (3-79) to Lys (T582). The relative expression of the candidate gene in virescent plants was extensively lower than that in normal plants. Nullification of the gene by VIGS significantly turned the green leaf of normal cotton plants into yellow. We named this candidate gene as GhRVL. Conclusions: This study will facilitate the further research on virescent formation, and will be useful for breeding of hybrid cottons.

Genetic basis of maize kernel oil-related traits revealed by high-density SNP markers in a recombinant inbred line population

“…The ultimate goal of QTL mapping is to clone the causal genes for further application in trait improvement. It usually takes a long time to obtain genes underlying QTLs by constructing near-isogenic lines in maize [ 47 – 49 ], rice [ 50 – 52 ], wheat [ 53 , 54 ] and other plants [ 55 , 56 ]. Combining linkage analysis and GWAS can greatly shorten the journey [ 57 , 58 ], and gene-based association studies can help identify the favorable allele.…”

Role of SNPs in determining QTLs for major traits in cotton

“…Sequence analysis of wild and mutant alleles showed the differences in four SNPs at sequence positions 426, 450, 709 and 1 082. It was further revealed that the SNP at position 1 082 caused a point mutation that resulted in synthesis of arginine instead of lysine in mutant polypeptides (Zhang et al 2018b). In another study, genetic diversity for leaf transcriptomes was identified in G. barbadense.…”