Rice stripe1-2 and stripe1-3 Mutants Encoding the Small Subunit of Ribonucleotide Reductase Are Temperature Sensitive and Are Required for Chlorophyll Biosynthesis |
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Authors: | Xiaoqiong Chen Ling Zhu Long Xin Kangxi Du Xiuhua Ran Xiaoyun Cui Quanju Xiang Hongyu Zhang Peizhou Xu Xianjun Wu |
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Affiliation: | 1. Rice Research Institute of Sichuan Agricultural University, Key Laboratory of Southwest Crop Genetic Resources and Improvement Ministry of Education, 211 Huimin Road, 611130 Wenjiang, Sichuan, China.; 2. College of Resources, Sichuan Agricultural University, 211 Huimin Road, 611130 Wenjiang, Sichuan, China.; China National Rice Research Institute, CHINA, |
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Abstract: | We induced mutants, stripe1-2 (st1-2) and stripe1-3 (st1-3), from rice (Oryza sativa L.) Indica 9311 using Ethyl methanesulfonate (EMS). Both st1-2 and st1-3 mutants encoded the small subunit of ribonucleotide reductase 1 (RNRS1), differed in the location of the mutated base, and displayed white-stripe from the L2 stage through maturity. The mutants were sensitive to temperature, and their chlorophyll content increased with the increase in temperature; however, they did not revert to normal green leaf phenotype under field conditions. The mutant st1-2 showed loosely arranged thylakoid lamellar structure as compared with wild-type (WT) plants. Contrastingly, st1-3 displayed normal thylakoid lamellar structure, good agronomic traits, and higher yield than st1-2 but lower yield than WT. Three-dimensional structure prediction for RNRS1 indicated that the mutation in Val-171 residue in st1-2 influenced the connection of RNRS1 to iron, causing abnormal development of chloroplasts. Real-time PCR analysis showed that the expression levels associated with chlorophyll biosynthetic pathway and photosynthesis were affected in st1-2 and st1-3 at different temperatures and different developmental stages. |
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