New Findings On Gene Regulation Of Seed Shattering and Dormancy In Red Rice

The better understanding of seed shattering and dormancy regulation in red rice can be used to understand the rice evolution and to develop biotechnological procedures to mitigate the problems caused by this weed. The main objectives of this study were to evaluate the importance of the known genes and to identify new genes evolved in the seed shattering and dormancy in red rice. The seed shattering and dormancy rate of the evaluated genotypes ranged from 20 to 270 gf and 15 to 78 %, respectively. The genes Sh4 and qSH1 commonly related to seed shattering had no effect on the evaluated genotypes. The expression of the genes OsCPL1 and OsXTH8 was directly related, and of the gene OsCel9D was inversely associated with seed shattering. A SSH study identified 154 cloned genes differentially expressed that may be related to seed shattering. A SNP of the gene Os08g0512400 at the position 1271 was associated with seed shattering. In addition, the exon 5 of the gene Os01g0849100 presented two SNPs at positions 2981 and 3057 related to seed shattering. The genes OsCYP707A5 and SDR4 were not differentially expressed, and the expression of the gene OsMADS2 at 14 days after anthesis was associated with the absence of seed dormancy. The variability of seed shattering in red rice is related with several genes. In addition to the know genes qSH1, Sh4 and OsCPL1, the genes OsXTH8, OsCel9D, Os08g0512400 and Os01g0849100 are also related to seed shattering in rice.