Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, 464-8601, Japan.
RIKEN Center for Sustainable Resource Science, Kanagawa, 230-0045, Japan.
Commun Biol. 2020 Jun 11;3(1):302. doi: 10.1038/s42003-020-1036-8.
Panicle architecture directly affects crop productivity and is a key target of high-yield rice breeding. Panicle length strongly affects panicle architecture, but the underlying regulatory mechanisms are largely unknown. Here, we show that two quantitative trait loci (QTLs), PANICLE RACHIS LENGTH5 (Prl5) and PRIMARY BRANCH LENGTH6 (Pbl6), independently regulate panicle length in rice. Prl5 encodes a gibberellin biosynthesis enzyme, OsGA20ox4. The expression of Prl5 was higher in young panicles resulting in panicle rachis elongation. Pbl6 is identical to ABERRANT PANICLE ORGANIZATION 1 (APO1), encoding an F-box-containing protein. We found a novel function that higher expression of Pbl6 is responsible for primary branch elongation. RNA-seq analysis revealed that these two genes independently regulate panicle length at the level of gene expression. QTL pyramiding of both genes increased panicle length and productivity. By combining these two genes in various combinations, we designed numerous panicle architecture without trade-off relationship.
穗型结构直接影响作物产量，是水稻高产育种的关键目标。穗长强烈影响穗型结构，但潜在的调控机制在很大程度上尚不清楚。在这里，我们展示了两个数量性状位点（QTL），即稻穗长 5 号（Prl5）和主枝长 6 号（Pbl6），它们独立调控水稻的穗长。Prl5 编码赤霉素生物合成酶 OsGA20ox4。Prl5 在幼穗中的表达较高，导致穗轴伸长。Pbl6 与异常穗组织 1（APO1）相同，编码一个含有 F-box 的蛋白质。我们发现了一个新的功能，即 Pbl6 的高表达负责主枝伸长。RNA-seq 分析表明，这两个基因独立地在基因表达水平上调控穗长。这两个基因的 QTL 聚合增加了穗长和产量。通过将这两个基因以各种组合结合起来，我们设计了许多没有权衡关系的穗型结构。
