利用EMS诱变粳稻品种武运粳7号获得一个新窄叶突变体nal10,该突变体在苗期表现出极窄叶和弱小的特征,在生殖期表现出矮化、窄叶、畸颖和不育的表型。组织解剖学分析表明,nal10的叶片窄化可能是由于叶片大脉和小脉数量减少造成的。遗传分析表明,该窄叶表型受一对隐性核基因控制。利用nal10与台中本地一号(TN1)构建的F2群体,通过混合分离法,在第1染色体上找到3个紧密连锁的SSR标记(RM1287、RM562和RM5638)。进一步利用新发展的分子标记,最终将该基因定位在STS标记PK83和PK78之间的55.2kb范围内,该区间共有8个开放阅读框。RT-PCR分析表明,NAL10的突变能够造成生长素生物合成、信号转导和运输基因转录水平的下降,因此NAL10是一个与生长素相关的窄叶新基因。这些结果为进一步克隆该基因、丰富水稻叶发育的遗传调控网络打下了基础。
A novel rice mutant narrow leaf 10(nal10)was identified from an EMS(ethyl methane sulphonate)mutagenized population of Wuyunjing 7.The mutant was characterized by narrow leaves and smaller architecture phenotype at the seedling stage,and dwarf,narrow leaves,deformed flowers and male sterility at the reproduction stage.Cyto-anatomical analysis indicated that the mutant had fewer large and small veins compared with the wild-type,which may account for the narrow leaf phenotype.The genetic analysis indicated the narrow leaf trait was controlled by a recessive nuclear gene.Using F2 population derived from the cross of nal10 and Taizhongbendi 1,three closely linked SSR markers RM1287,RM562 and RM5638on chromosome 1were obtained by the bulked segregant analysis method.With the developed new markers,the gene was finally fine-mapped to an interval of 55.2kb between the STS markers PK83 and PK78,where a total of eight ORFs were found.RT-PCR analysis indicated the expression levels of auxin biosynthesis,signal transduction and transport related genes were all down-regulated,suggesting NAL10 is a new narrow leaf gene involving in the auxin metabolism.These results laid a foundation for further cloning of the gene and enrich the genetic regulation network of leaf development in rice.