水稻卷叶矮化突变体rld的表型鉴定及基因精细定位

Phenotypic identification and gene-fine mapping of a rolling leaf and dwarf mutant rld in rice

为了研究引起水稻叶片卷曲的分子机理,鉴定出新的水稻卷叶基因.用60Co-γ射线辐射诱变籼稻品种镇恢084,获得一份卷叶矮化突变体材料,命名为rld(rolling leaf and dwarf).通过形态学分析水稻表型,石蜡切片观察叶片细胞组织形态,图位克隆和测序技术进行精细定位和确定目的基因,生物信息学分析蛋白序列结构.结果显示:rld突变体叶片极度内卷,株高降低,穗长变短,结实率降低;rld突变体叶片维管束间的下表皮叶肉细胞面积增大;rld基因精细定位在标记Indel2和Indel5间的32.3kb的物理区间,测序发现rld是调控卷叶基因RL9的一个新等位基因,由于外显子上精氨酸缺失引起rld基因编码的蛋白空间结构发生改变.推测精氨酸在RL9蛋白的正常功能行使过程中是必要的,对维持水稻叶片表型具有至关重要的作用.

In order to study the molecular mechanism of rice leaf curl,to identify new rice leaf rolling gene,mutant indica rice variety Zhenhui 084 was induced by 60 Co-γ-ray irradiation,a coiled leaf mutant material was obtained,named rld (rolling leaf and dwarf ).Morphological analysis of rice phenotype,paraffin section observation of leaf cell tissue,the map cloning method and high-throughput sequencing technology were used to finely locate and identify the target gene,the bioinformatics analysis of protein sequence structure.The results showed that the rld mutant leaves were extremely involunted,the plant height was reduced,the panicle length was shortened,and the seed setting rate was reduced.Observation of paraffin sections of leaves showed apparent increase of cell area in the dermis of the rld mutant leaves.The rld gene was finely mapped between the markers Indel2 and Indel5,and the physical distance was 32.3 kb,sequencing found that rld was a new allele that regulates the leaf rolling gene RL9.The spatial structure of the protein encoded by the rld gene changed due to arginine deletion on the exon.It was inferred that arginine was essential for the normal function of RL9 protein and played an important role in maintaining the leaf phenotype of rice.