Joint International Research Laboratory of Metabolic & Developmental Sciences, State Key Laboratory of Hybrid Rice, SJTU-University of Adelaide Joint Centre for Agriculture and Health, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.
Centre for Plant Integrative Biology, School of Biosciences, University of Nottingham, Loughborough Leicstershire, LE12 5RD, Nottingham, UK.
Nat Commun. 2018 Jun 11;9(1):2346. doi: 10.1038/s41467-018-04710-x.
Root angle has a major impact on acquisition of nutrients like phosphate that accumulate in topsoil and in many species; low phosphate induces shallower root growth as an adaptive response. Identifying genes and mechanisms controlling root angle is therefore of paramount importance to plant breeding. Here we show that the actin-binding protein Rice Morphology Determinant (RMD) controls root growth angle by linking actin filaments and gravity-sensing organelles termed statoliths. RMD is upregulated in response to low external phosphate and mutants lacking of RMD have steeper crown root growth angles that are unresponsive to phosphate levels. RMD protein localizes to the surface of statoliths, and rmd mutants exhibit faster gravitropic response owing to more rapid statoliths movement. We conclude that adaptive changes to root angle in response to external phosphate availability are RMD dependent, providing a potential target for breeders.
根角对养分的获取有重大影响，如在表土和许多物种中积累的磷酸盐；低磷酸盐会诱导较浅的根生长，作为一种适应反应。因此，鉴定控制根角的基因和机制对植物育种至关重要。在这里，我们表明肌动蛋白结合蛋白 Rice Morphology Determinant（RMD）通过连接肌动蛋白丝和重力感应细胞器称为平衡石来控制根生长角度。RMD 在低外部磷酸盐的刺激下上调，缺乏 RMD 的突变体具有更陡峭的冠根生长角度，对磷酸盐水平没有反应。RMD 蛋白定位于平衡石的表面，rmd 突变体表现出更快的向重力性反应，因为平衡石的运动更快。我们得出结论，根角对外界磷酸盐供应的适应性变化依赖于 RMD，为育种者提供了一个潜在的目标。
