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

Youping Zhang,Dongyun Zuo,Simin Li,Javaria Ashraf,Ke Liu,John Z Yu,Qiaolian Wang,Hailiang Cheng,Xiaoxu Feng,Guoli Song

doi:10.1186/s42397-018-0009-7

Abstract

BackgroundVirescence, 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.MethodsIn current study, for fine mapping of virescent-1 (v1) 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.ResultsThe v1 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.ConclusionsThis study will facilitate the further research on virescent formation, and will be useful for breeding of hybrid cottons.

Highlights

Virescence, as a recognizable phenotype in the early development stage of cotton, is available for research on chloroplast development and photosynthesis and for heterosis exploitation in cotton
The whole pathway of Chl biosynthesis is consisted of 27 genes that encode 15 enzymes from glutamyl-tRNA to Chl b in Arabidopsis (Zhu et al 2014; Wang et al 2016a, 2016b)
Same as ZHANG et al Journal of Cotton Research (2018) 1:10 in Arabidopsis, the mutant cs directly involved in Chl biosynthesis by motivating the ATP-dependent binding of Mg2+ into protoporphyrin IX (Rissler et al 2002; Ikegami et al 2007), exhibiting the yellowish leaf phenotype (Koncz et al 1990; Kobayashi et al 2008)

Summary

Introduction

Virescence, as a recognizable phenotype in the early development stage of cotton, is available for research on chloroplast development and photosynthesis and for heterosis exploitation in cotton. The phenotype of the virescent mutant is characterized by yellowish leaves at the early stage, which gradually become normal green leaves at maturity. Same as ZHANG et al Journal of Cotton Research (2018) 1:10 in Arabidopsis, the mutant cs directly involved in Chl biosynthesis by motivating the ATP-dependent binding of Mg2+ into protoporphyrin IX (Rissler et al 2002; Ikegami et al 2007), exhibiting the yellowish leaf phenotype (Koncz et al 1990; Kobayashi et al 2008). Elevated accumulation of the OsHO2 (Heme oxygenase) into Mg-protoporphyrin IX in rice caused the leaf color mutant (Li et al 2014b)

Methods

Results

Conclusion