State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou 510642, China.
College of Life Sciences, South China Agricultural University, Guangzhou 510642, China.
Int J Mol Sci. 2022 Aug 21;23(16):9452. doi: 10.3390/ijms23169452.
Tiller angle is an important trait that determines plant architecture and yield in cereal crops. Tiller angle is partially controlled during gravistimulation by the dynamic re-allocation of LAZY1 (LA1) protein between the nucleus and plasma membrane, but the underlying mechanism remains unclear. In this study, we identified and characterized a new allele of based on analysis of a rice ( L.) spreading-tiller mutant , which harbors a non-synonymous mutation in the predicted transmembrane (TM) domain-encoding region of this gene. The mutation causes complete loss of shoot gravitropism, leading to prostrate growth of plants. Our results showed that LA1 localizes not only to the nucleus and plasma membrane but also to the endoplasmic reticulum. Removal of the TM domain in LA1 showed spreading-tiller phenotype of plants similar to but did not affect the plasma membrane localization; thus, making it distinct from its ortholog ZmLA1 in . Therefore, we propose that the TM domain is indispensable for the biological function of LA1, but this domain does not determine the localization of the protein to the plasma membrane. Our study provides new insights into the -mediated regulation of shoot gravitropism.
蘖角度是决定谷类作物植物结构和产量的一个重要特征。在向地性刺激下，蘖角度部分通过 LAZY1（LA1）蛋白在核和质膜之间的动态重新分配来控制，但潜在机制尚不清楚。在这项研究中，我们根据对一种水稻（L.）展蘖突变体的分析，鉴定并表征了一个新的等位基因，该基因在该基因的预测跨膜（TM）结构域编码区存在非同义突变。该突变导致植株完全丧失茎向地性，导致植株匍匐生长。我们的结果表明，LA1不仅定位于核和质膜，也定位于内质网。在 LA1 中去除 TM 结构域会导致植株表现出与 类似的展蘖表型，但不影响质膜定位；因此，与玉米中的同源物 ZmLA1 不同。因此，我们提出 TM 结构域对于 LA1 的生物学功能是必不可少的，但该结构域并不决定该蛋白向质膜的定位。我们的研究为 LA1 介导的茎向地性调节提供了新的见解。
