Cloning and Expression of Gene Responsible for High-Tillering Dwarf Phenotype in Indica Rice Mutant gsor23

• Published in: Rice science Vol. 20; no. 5; pp. 320 - 328
• Main Authors: YUAN, Shou-jiang, WANG, Tao, YIN, Liang, ZHAO, Jin-feng, WAN, Jian-min, LI, Xue-yong
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.09.2013; National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China; National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agriculture Sciences, Beijing 100081, China; Shandong Rice Research Institute, Jinan 250100, China%National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agriculture Sciences, Beijing 100081, China%Shandong Rice Research Institute, Jinan 250100, China%National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agriculture Sciences, Beijing 100081, China
• Subjects: alleles; amino acids; biosynthesis; carotenoid-cleaving dioxygenase; chromosomes; cytosine; feedback regulation; frameshift mutation; gamma radiation; gene expression; gene expression regulation; high-tillering dwarf mutant; leaves; mutants; phenotype; plant hormones; positional cloning; recessive genes; reverse transcriptase polymerase chain reaction; rice; roots; RT-PCR分析; sequence analysis; signal transduction; strigolactone; 克隆与表达; 分蘖; 水稻; 生物合成基因; 矮化; 矮秆突变体; 隐性基因; carotenoid-cleaving dioxygenase; positional cloning; feedback regulation; rice; strigolactone; high-tillering dwarf mutant
• DOI: 10.1016/S1672-6308(13)60134-1
• ISSN: 1672-6308

High-tillering dwarf mutant gsor23 was generated from an indica rice variety Indica9 radiatied by y-ray. Genetic analysis showed that this phenotype was controlled by one single recessive gene, which was mapped within a physical distance of 386 kb between two insertion-deletion （InDel） markers CI-WT2 and C1-WT4 on the long arm of chromosome 1. There is a known gene DIO within this region, the mutation of which causes high-tillering in rice. Sequence analysis of the DIO allele in gsor23 revealed that the base cytosine （C） at the 404th position in the coding region was deleted, which would cause frameshift mutation after the 134th amino acids. The mutation site and indica background of gsor23 were different from the previously reported japonica mutants d10-1 and d10-2. Therefore, gsor23 is a novel allelic mutant of D10 which encodes the carotenoid-cleaving dioxygenase 8 （CCD8）, a key enzyme involved in the biosynthesis of the new plant hormone strigolactones （SLs）. After treatment with GR24, a synthetic analogue of SLs, the high-tillering phenotype of gsor23 was restored to normal. Real-time RT-PCR analysis showed that D10 expression was high in roots, but low in leaves. Compared with the wild type Indica9, the expression of the SL biosynthesis gene DIO was upregulated, while genes likely involved in the SL signal transduction pathway such as D3 and D14 were down-regulated in the gsor23 mutant.