一个水稻类病变黄叶突变体的鉴定和精细定位

Identification and Fine Mapping of a Spotted and Yellow Leaf Mutant in Rice

从15 000多个水稻转基因株系中发现了一个类病变黄叶突变体。该突变体最显著的特征为叶片由下而上依次黄化,同时出现类似病原体感染的病斑。根据突变体表型,将该突变体命名为syl1(spotted and yellow leaves 1)。遗传学分析表明,该突变性状受1对隐性核基因控制。PCR检测和潮霉素抗性分析显示,该突变表型不是由T-DNA插入引起的。为了克隆该基因,将此突变体和籼稻品种龙特甫杂交获得F2和F3定位群体,利用网上公布的SSR标记首先将突变基因定位在第12染色体短臂端分子标记RM7619附近。随后利用日本晴和9311序列的差异,在该区域新设计了9对InDel分子标记,进一步将syl1基因定位在BAC克隆OSJNBa0002O20内分子标记WL32与WL35之间约102kb的区域。为进一步克隆syl1基因奠定了基础。

A spotted and yellow leaf mutant was isolated from more than 15 000 transgenic rice lines.The mutant was featured by lesion-mimic spots during the whole growth stage as well as leaf etiolation one by one from lower part to upper part.Genetic analysis revealed that the mutation was controlled by a single recessive gene,which was designated as syl1（spotted and yellow leaves 1）.PCR analysis and hygromycin resistance assay showed that the mutation was not caused by T-DNA insertion.To isolate the syl1 gene,a positional cloning strategy was employed.The approximate map position of the syl1 gene was determined by SSR markers from published data,and then nine new InDel markers were developed.A high-resolution physical map of the chromosomal region around the syl1 gene was made using F2 and F3 populations consisting of 1328 mutant individuals.Finally,the syl1 gene was located within 102 kb region between InDel markers WL32 and WL35 within the BAC clone OSJNBa0002O20 on chromosome 12.