如何进一步提高水稻的单产，这是关乎国计民生的重要课题。中国科学家４日在《细胞研究》上发表报告说，他们发现一个关键基因能调控水稻“理想株型”并有潜力增加其产量，这将有助未来培育出更高产量的水稻品种。

上世纪７０年代，日本科学家提出水稻理想株型的理论，９０年代国际水稻研究所的科学家在实践中得以应用和发展，并培育了一些株型与产量方面具有突破性提升的水稻新品系。近年来，随着水稻功能基因组学发展，一些影响水稻产量的关键基因相继被克隆，但对水稻理想株型育种的分子调控机制仍不是很清楚。

为此，中国科学院遗传与发育生物学研究所傅向东与中国农业科学院水稻研究所钱前领衔的团队，利用国际水稻研究所培育的理想株型新品系与中国水稻品种春江０６杂交后，根据其后代的遗传信息，成功分离并克隆了一个关键基因ＮＰＴ１。

据团队介绍，ＮＰＴ１能够调控水稻理想株型并有潜力增加其产量，将这一个基因和其他等位基因ＤＥＰ１聚合导入中国现有高产水稻品种后，在现有产量基础上还能进一步提高水稻的产量。

傅向东告诉新华社记者：“原来不知道具体是哪个基因控制，限制了理想株型育种的推广。现在，我们知道了ＮＰＴ１基因的作用，这会给育种工作带来很大便利，从而更容易培育出高产水稻品种。”

据傅向东介绍，团队已开始与负责育种的专业人士合作，估计２至３年后就能培育出新的高产水稻品种，并且未来还有可能开展国际合作，把相关技术推广到更多地区。（来源：新华社 张家伟）

Non-canonical regulation of SPL transcription factors by a human OTUB1-like deubiquitinase defines a new plant type rice associated with higher grain yield

Abstract  Achieving increased grain productivity has long been the overriding focus of cereal breeding programs. The ideotype approach has been used to improve rice yield potential at the International Rice Research Institute and in China. However, the genetic basis of yield-related traits in rice remains unclear. Here, we show that a major quantitative trait locus, qNPT1, acts through the determination of a 'new plant type' (NPT) architecture characterized by fewer tillers, sturdier culms and larger panicles, and it encodes a deubiquitinating enzyme with homology to human OTUB1. Downregulation of OsOTUB1 enhances meristematic activity, resulting in reduced tiller number, increased grain number, enhanced grain weight and a consequent increase in grain yield in rice. Unlike human OTUB1, OsOTUB1 can cleave both K48- and K63-linked polyubiquitin. OsOTUB1 interacts with the E2 ubiquitin-conjugating protein OsUBC13 and the squamosa promoter-binding protein-like transcription factor OsSPL14. OsOTUB1 and OsSPL14 share common target genes, and their physical interaction limits K63-linked ubiquitination (K63Ub) of OsSPL14, which in turn promotes K48Ub-dependent proteasomal degradation of OsSPL14. Conversely, loss-of-function of OsOTUB1 is correlated with the accumulation of high levels of OsSPL14, resulting in the NPT architecture. We also demonstrated that pyramiding of high-yielding npt1 and dep1-1 alleles provides a new strategy for increasing rice yield potential above what is currently achievable.

原文链接：http://www.nature.com/cr/journal/vaop/ncurrent/full/cr201798a.html?foxtrotcallback=true