Table_1.XLS

Leaf color mutants in higher plants are ideal materials for investigating the structure and function of photosynthetic system. In this study, we identified a cucumber vyl (virescent-yellow leaf) mutant in the mutant library, which exhibited reduced pigment contents and delayed chloroplast development process. F2 and BC1 populations were constructed from the cross between vyl mutant and cucumber inbred line ‘Hazerd’ to identify that the vyl trait is controlled by a simply recessive gene designated as CsVYL. The CsVYL gene was mapped to a 3.8 cM interval on chromosome 4 using these 80 F2 individuals and BSA (bulked segregation analysis) approach. Fine genetic map was conducted with 1542 F2 plants and narrowed down the vyl locus to an 86.3 kb genomic region, which contains a total of 11 genes. Sequence alignment between the wild type (WT) and vyl only identified one single nucleotide mutation (C→T) in the first exon of gene Csa4G637110, which encodes a DnaJ-like zinc finger protein. Gene Expression analysis confirmed the differences in transcription level of Csa4G637110 between wild type and mutant plants. Map-based cloning of the CsVYL gene could accelerate the study of chloroplast development and chlorophyll synthesis of cucumber.

高等植物中的叶色突变体是研究光合系统结构与功能的理想材料。本研究中，我们从突变体库中鉴定出一种黄瓜的vyl（淡黄叶）突变体，该突变体表现出色素含量降低和叶绿体发育进程延缓。通过将vyl突变体与黄瓜自交系‘Hazerd’杂交，构建了F2和BC1群体，以确定vyl性状受一个被指定为CsVYL的简单隐性基因控制。利用这些80个F2个体和BSA（块状分离分析）方法，将CsVYL基因定位到染色体4上的3.8 cM区间。通过1542个F2植株进行的精细遗传图谱绘制，将vyl位点缩小至一个86.3 kb的基因组区域，该区域包含总计11个基因。野生型（WT）与vyl之间的序列比对仅发现了基因Csa4G637110的第一个外显子中的一个单核苷酸突变（C→T），该基因编码一种DnaJ样锌指蛋白。基因表达分析证实了野生型植物与突变型植物中Csa4G637110转录水平的差异。基于图谱的CsVYL基因克隆可加速黄瓜叶绿体发育和叶绿素合成的相关研究。