National Key Laboratory of Plant Molecular Genetics and National Center of Plant Gene Research, Institute of Plant Physiology &Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
Shanghai Center for Plant Stress Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 201602, China.
Nat Commun. 2017 Mar 20;8:14789. doi: 10.1038/ncomms14789.
Super hybrid rice varieties with ideal plant architecture (IPA) have been critical in enhancing food security worldwide. However, the molecular mechanisms underlying their improved yield remain unclear. Here, we report the identification of a QTL, qWS8/ipa1-2D, in the super rice Yongyou12 (YY12) and related varieties. In-depth genetic molecular characterization of qWS8/ipa1-2D reveals that this newly identified QTL results from three distal naturally occurring tandem repeats upstream of IPA1, a key gene/locus previously shown to shape rice ideal plant architecture and greatly enhance grain yield. The qWS8/ipa1-2D locus is associated with reduced DNA methylation and a more open chromatin state at the IPA1 promoter, thus alleviating the epigenetic repression of IPA1 mediated by nearby heterochromatin. Our findings reveal that IPA traits can be fine-tuned by manipulating IPA1 expression and that an optimal IPA1 expression/dose may lead to an ideal yield, demonstrating a practical approach to efficiently design elite super rice varieties.
超级杂交稻品种具有理想的株型结构（IPA），对全球粮食安全至关重要。然而，其产量提高的分子机制尚不清楚。在这里，我们报道了在超级稻 Yongyou12（YY12）及其相关品种中鉴定到一个 QTL，qWS8/ipa1-2D。对 qWS8/ipa1-2D 的深入遗传分子特征分析表明，这个新鉴定的 QTL 是由 IPA1 上游三个自然发生的串联重复引起的，IPA1 是一个关键基因/基因座，先前的研究表明它可以塑造水稻理想的株型结构并极大地提高籽粒产量。qWS8/ipa1-2D 位点与 IPA1 启动子处的 DNA 甲基化减少和更开放的染色质状态相关，从而减轻了附近异染色质对 IPA1 的表观遗传抑制。我们的研究结果表明，可以通过操纵 IPA1 的表达来微调 IPA 特性，并且 IPA1 的最佳表达/剂量可能会导致理想的产量，这证明了一种有效设计优秀超级稻品种的实用方法。
