Wang Pingyu, Li Chunmei, Wang Yang, Huang Rui, Sun Changhui, Xu Zhengjun, Zhu Jianqing, Gao Xiaoling, Deng Xiaojian, Wang Pingrong
Rice Research Institute, Sichuan Agricultural University, Chengdu, 611130 Sichuan, China.
Springerplus. 2014 Apr 24;3:201. doi: 10.1186/2193-1801-3-201. eCollection 2014.
Geranylgeranyl reductase (CHL P) catalyzes the reduction of geranylgeranyl diphosphate to phytyl diphosphate, and provides phytol for both Chlorophyll (Chl) and tocopherol synthesis. In this study, we isolated a yellow-green leaf mutant, 502ys, in rice (Oryza sativa). The mutant exhibited reduced level of Chls, arrested development of chloroplasts, and retarded growth rate. The phenotype of the 502ys mutant was controlled by by a recessive mutation in a nuclear gene on the long arm of rice chromosome 2. Map-based cloning of the mutant resulted in the identification of an OsChl P gene (LOC_Os02g51080). In the 502ys mutant, a single base pair mutation was detected at residue 1279 in DNA sequence of the gene, resulting in an amino acid change (Gly-206 to Ser) in the encoded protein. HPLC analysis of Chls indicated that the majority of Chl molecules are conjugated with an unsaturated geranylgeraniol side chain, in addition to small amount of normal Chls in the mutant. Furthermore, the mutant phenotype was complemented by transformation with the wild-type gene. Therefore, this study has confirmed the 502ys mutant resulted from a single base pair mutation in OsChl P gene.
香叶基香叶基还原酶（CHL P）催化香叶基香叶基二磷酸还原为植基二磷酸，并为叶绿素（Chl）和生育酚的合成提供植醇。在本研究中，我们在水稻（Oryza sativa）中分离出一个黄绿叶片突变体502ys。该突变体叶绿素水平降低，叶绿体发育停滞，生长速率减缓。502ys突变体的表型由水稻第2号染色体长臂上一个核基因的隐性突变控制。通过图位克隆该突变体，鉴定出一个OsChl P基因（LOC_Os02g51080）。在502ys突变体中，该基因DNA序列第1279位残基处检测到一个单碱基对突变，导致编码蛋白中的一个氨基酸变化（甘氨酸-206突变为丝氨酸）。叶绿素的高效液相色谱分析表明，除了突变体中有少量正常叶绿素外，大多数叶绿素分子与不饱和香叶基香叶醇侧链结合。此外，野生型基因转化可互补突变体表型。因此，本研究证实502ys突变体是由OsChl P基因的单碱基对突变导致的。
