Teosinte ligule allele narrows plant architecture and enhances high-density maize yields

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

Corresponding author: Feng Tian

Increased planting densities have boosted maize yields. Upright plant architecture facilitates dense planting. Here, we cloned UPA1 (Upright Plant Architecture1) and UPA2, two quantitative trait loci conferring upright plant architecture. UPA2 is controlled by a two-base sequence polymorphism regulating the expression of a B3-domain transcription factor (ZmRAVL1) located 9.5 kilobases downstream. UPA2 exhibits differential binding by DRL1 (DROOPING LEAF1), and DRL1 physically interacts with LG1 (LIGULELESS1) and represses LG1 activation of ZmRAVL1. ZmRAVL1 regulates brd1 (brassinosteroid C-6 oxidase1), which underlies UPA1, altering endogenous brassinosteroid content and leaf angle. The UPA2 allele that reduces leaf angle originated from teosinte, the wild ancestor of maize, and has been lost during maize domestication. Introgressing the wild UPA2 allele into modern hybrids and editing ZmRAVL1 enhance high-density maize yields.

增加种植密度能够提高玉米的产量。而挺直的株型结构有利于种植密度的增加。本文中，作者克隆到了挺直株型结构基因UPA1和UPA2，这两个数量性状位点赋予了植物挺直的株型结构。UPA2由双碱基多态性所控制，调控下游9.5Kb处的一个含有B3结构域的转录因子ZmRAVL1的表达。UPA2上存在不同的叶下垂基因DRL1的结合位点，而DRL1能够与无叶舌基因LG1进行物理互作，抑制ZmRAVL1介导的LG1激活。ZmRAVL1调控油菜素内酯C6氧化酶基因brd1，改变植株内源的油菜素内酯含量和叶片角度，而该基因正是数量性状位点UPA1的功能基因。来自玉米野生祖先大刍草的UPA2等位基因能够减小叶片角度，但其在玉米驯化过程中丢失。通过将野生UPA2等位基因导入到现在玉米杂交种中和编辑ZmRAVL1基因都能增强高密度种植玉米的产量。

通讯：田丰  (http://cab.cau.edu.cn/art/2017/6/9/art_27218_78.html)

个人简介：1998-2002年，湖北农学院，学士；2002-2007年，中国农业大学，博士；2007-2011年，康奈尔大学，博士后 。

研究方向：玉米驯化、适应遗传基础的系统解析；玉米重要驯化、适应位点的基因克隆和分子进化机制；玉米野生祖先种大刍草优良等位基因的发掘和利用；玉米复杂数量性状全基因组关联分析。

doi: 10.1126/science.aax5482

Journal: Science

Published date: August 16, 2019