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...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.展开更多
Tiller number and culm length are important components of plant architecture and determinate grain production in rice.A line SIL046, derived from an introgression lines population developed by an accession of common w...Tiller number and culm length are important components of plant architecture and determinate grain production in rice.A line SIL046, derived from an introgression lines population developed by an accession of common wild rice（Oryza rufipogon Griff.） and a high-yielding indica cultivar Guichao 2（Oryza sativa L.）,exhibits a higher tiller number and shorter culm length phenotype than the recipient parent Guichao 2（GC2）.Genetic analysis showed that the high-tillering dwarf phenotype was controlled by a novel single recessive gene,referred to as the high-tillering dwarf 3（htd3）,which located within the genetic distance of 13.4 cM between SSR makers RM7003 and RM277 on chromosome 12.By means of fine-mapping strategy,we mapped HTD3 gene within the genetic distance of 2.5 cM and the physical distance of 3100 kb in the centromere of chromosome 12.Further identification of HTD3 gene would provide a new opportunity to uncover the molecular mechanism of the development of culm and tiller,two important components of yields in rice.展开更多
基金supported by grants from the National Natural Science Foundation of China(GrantNo.31271311)the Ministry of Agriculture of China(Grant No.2011ZX08009-003)
文摘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.
基金supported by the Project of Conservation and Utilization of Agro-Wild Plants of the Ministry of Agriculture of China,and Special Fund for Agro-scientific Research in the Public Interest(No.201003021)
文摘Tiller number and culm length are important components of plant architecture and determinate grain production in rice.A line SIL046, derived from an introgression lines population developed by an accession of common wild rice（Oryza rufipogon Griff.） and a high-yielding indica cultivar Guichao 2（Oryza sativa L.）,exhibits a higher tiller number and shorter culm length phenotype than the recipient parent Guichao 2（GC2）.Genetic analysis showed that the high-tillering dwarf phenotype was controlled by a novel single recessive gene,referred to as the high-tillering dwarf 3（htd3）,which located within the genetic distance of 13.4 cM between SSR makers RM7003 and RM277 on chromosome 12.By means of fine-mapping strategy,we mapped HTD3 gene within the genetic distance of 2.5 cM and the physical distance of 3100 kb in the centromere of chromosome 12.Further identification of HTD3 gene would provide a new opportunity to uncover the molecular mechanism of the development of culm and tiller,two important components of yields in rice.
