水稻窄叶突变体zy103突变基因鉴定

为通过叶形相关基因定位与克隆解析水稻叶形变异的分子机制,本研究以籼稻品种9311与粳稻品种豫粳6号的杂交F₇株系中发现的窄叶突变体zy103为试验材料,应用(zy103/9311)F₂、F₃分离群体对窄叶基因进行精细定位及候选基因预测。表型分析表明,突变体zy103出现全生育期叶片变窄微卷、株高及结实率降低、成熟种子弯曲变形等变异表型。遗传分析和基因定位结果表明,突变体zy103受1对隐性核基因控制,该基因被定位于第12号染色体195.4 kb的区间内,此区间内共预测了28个编码基因。对区间内与水稻叶形态建成相关的OsCSLD4(LOC_Os12g36890.1)基因进行测序,结果表明,突变体中OsCSLD4基因的编码区第2外显子第3 472~第3 479处有8个核苷酸(TGTGCCAC)缺失,造成移码突变,导致原编码蛋白第Ⅶ和第Ⅷ跨膜区保守功能结构域丢失,推测OsCSLD4是引起突变体zy103窄叶突变的目的基因。本研究结果为解析水稻窄叶形成的分子机理和水稻理想株型育种奠定了一定的理论基础。

Gene Identification of Narrow Leaf Mutant zy103 in Rice

Mapping and cloning of genes related to leaf morphology is essential for understanding the molecular mechanism of leaf morphogenesis. We identified a narrow leaf mutant zy103, from the F₇ progeny of 9311 (Oryza sativa sup. indica)×Yujing 6 (O. sativa sup. japonica). With F₂ and F₃segregation populations derived from the cross between zy103 and 9311, the narrow leaf gene was finely mapped and the candidate genes were predicted. zy103 displayed narrow and semi-rolled leaves during the whole growing duration. Plant height and setting rate of zy103 were reduced, and the seeds were bended. Genetic analysis suggested that the phenotype of zy103 was controlled by one recessive nuclear gene, which was located within a 195.4 kb region on chromosome 12. There were 28 coding genes within this region. We further analyzed the candidate genes by sequencing. Eight nucleotides from 3 472 to 3 479 in the coding region of the OsCSLD4 (LOC_Os12g36890.1) gene were deleted, which caused a frameshift with concomitant loss of function the transmembrane domains of Ⅶ and Ⅷ. Therefore, OsCSLD4 is most likely to be the target gene of zy103. The results paved ways for further mechanism analysis and provided new variation for rice ideal-plant-type breeding.