Genetic control of seed shattering during African rice domestication

First author: Shuwei Lv; Affiliations: China Agricultural University (中国农业大学): Beijing, China

Corresponding author: Zuofeng Zhu

Domestication represents a unique opportunity to study the evolutionary process. The elimination of seed dispersal traits was a key step in the evolution of cereal crops under domestication. Here, we show that ObSH3, a YABBY transcription factor, is required for the development of the seed abscission layer (离层). Moreover, selecting a genomic segment deletion containing SH3 resulted in the loss of seed dispersal in populations of African cultivated rice (Oryza glaberrima Steud.). Functional characterization of SH3 and SH4 (another gene controlling seed shattering 落籽 on chromosome 4) revealed that multiple genes can lead to a spectrum of non-shattering phenotypes, affecting other traits such as ease of threshing (脱粒) that may be important to tune across different agroecologies (农业生态学) and postharvest practices (采后处理). The molecular evolution analyses of SH3 and SH4 in a panel of 93 landraces provided unprecedented (前所未有的) geographical detail of the domestication history of African rice, tracing multiple dispersals from a core heartland (中心地带) and introgression (基因渗入) from local wild rice. The cloning of ObSH3 not only provides new insights into a critical crop domestication process but also adds to the body of knowledge on the molecular mechanism of seed dispersal.

驯化是研究物种演化非常好的对象之一。种子散布性状的消除是谷类作物在驯化压力下演化的关键步骤。本文研究显示YABBY类转录因子ObSH3基因对于种子离层的发育至关重要。此外，对于带有SH3基因的一段基因组序列缺失的选择会导致非洲栽培稻群体种子散布性状的消失。对于SH3以及另外一个位于4号染色体上的控制种子落粒相关的基因SH4的功能鉴定显示多个基因与非落粒表型相关，同时影响着其它的一些性状，比如脱粒的难易，可能对于农业生态学和采后处理非常重要。对于93个地方品种SH3和SH4的进化分析显示出以前并未发现的非洲稻地理驯化历史，从中心地带往外存在多个散布轨迹，同时还有地方野生稻的基因渗入。ObSH3基因的克隆不仅对于重要作物驯化过程有揭示作用，同时也为种子散布的分子机制提供了新的认识。

通讯：朱作峰 (http://cab.cau.edu.cn/art/2017/6/9/art_27217_96.html)

个人简介：1994-1998年，莱阳农学院，园艺系，学士；1998-2001年，中国农业大学，植物遗传育种系，硕士；2001-2004年，中国农业大学，植物遗传育种系，博士。

研究方向： 栽培水稻起源与演化的分子机理；水稻功能基因组；水稻分子育种。

doi: 10.1038/s41477-018-0164-3

Journal: Nature Plants

First Published: 04 June, 2018

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