State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming, China.
Institute of Rice Research, Agriculture College, Yunnan Agricultural University, Kunming, China.
J Exp Bot. 2018 Sep 14;69(20):4703-4713. doi: 10.1093/jxb/ery243.
The widespread introduction of semi-dwarf1 (sd1), also known as the 'Green Revolution' gene, has dramatically increased rice yield. However, the extensive use of limited sources of dwarf genes may cause 'bottleneck' effects in breeding new rice varieties. Alternative dwarf germplasms are quite urgent for rice breeding. Here, we characterized a new allele of the rice Slr1-d mutant, Slr1-d6, which reduced plant height by 37%, a much milder allele for dwarfism. Slr-d6 was still responsive to gibberellin (GA) to a reduced extent. The mutation site in Slr1-d6 was less conserved in the TVHYNP domain, leading to the specific semi-dominant dwarf phenotype. Expression of SLR1 and five key GA biosynthetic genes was disturbed in Slr1-d6, and the interaction between Slr1-d6 and GID1 was decreased. In the genetic background of cultivar 9311 with sd1 eliminated, Slr1-d6 homozygous plants were ~70 cm tall. Moreover, Slr1-d6 heterozygous plants were equivalent in height to the standard sd1 semi-dwarf 9311, but with a 25% yield increase, showing its potential application in hybrid rice breeding.
半矮化基因（sd1），也被称为“绿色革命”基因的广泛引入极大地提高了水稻产量。然而，广泛使用有限的矮化基因来源可能会在培育新的水稻品种中导致“瓶颈”效应。替代矮化种质对于水稻育种来说是相当紧迫的。在这里，我们对水稻 Slr1-d 突变体的一个新等位基因 Slr1-d6 进行了表征，该等位基因使株高降低了 37%，是一种更为温和的矮化等位基因。Slr-d6 对赤霉素（GA）的反应仍然在一定程度上受到抑制。Slr1-d6 中的突变位点在 TVHYNP 结构域的保守性较低，导致其表现出特异性的半显性矮化表型。Slr1-d6 中 SLR1 和五个关键 GA 生物合成基因的表达受到干扰，Slr1-d6 与 GID1 的相互作用减弱。在 sd1 消除的品种 9311 的遗传背景下，Slr1-d6 纯合植株的高度约为 70cm。此外，Slr1-d6 杂合植株的高度与标准的 sd1 半矮化 9311 相当，但产量增加了 25%，显示了其在杂交水稻育种中的潜在应用。
