Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, and Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
J Exp Bot. 2017 Oct 13;68(17):4885-4898. doi: 10.1093/jxb/erx309.
OVATE family proteins (OFPs) regulate multiple aspects of plant growth and development; however, their roles in responses to abiotic stresses have not yet been studied. Here, we report that rice OsOFP6 regulates growth and development, and alters responses to drought and cold stresses. OsOFP6 is expressed in various tissues and developmental stages. Knock-down of OsOFP6 by RNA interference (RNAi) resulted in semi-dwarf stature, altered grain shape, and shorter lateral roots. OsOFP6 was shown to interfere with auxin in regulating lateral root growth and initiation, as RNAi plants had increased density of lateral roots under IAA (indole-3-acetic acid) treatment. OsOFP6 also affects polar auxin transport, which was demonstrated by the different responses of RNAi and OsOFP6-overexpression (OE) plants to treatment with N-1-naphthylphalamic acid (NPA). Furthermore, under drought conditions OE lines showed slower water loss and less accumulation of H2O2 compared with RNAi plants, which displayed faster water loss and higher H2O2, implying that OsOFP6 may confer both drought avoidance and drought tolerance in rice plants. In addition, under cold treatment OE and RNAi plants exhibited lower and higher relative electrical conductivity (REC), respectively, suggesting an important role of OsOFP6 in response to cold stress. These results provide new insights into the multiple functions of OVATE family proteins.
卵形家族蛋白（OFPs）调节植物生长和发育的多个方面；然而，它们在应对非生物胁迫中的作用尚未得到研究。在这里，我们报告说，水稻 OsOFP6 调节生长和发育，并改变对干旱和寒冷胁迫的响应。OsOFP6 在各种组织和发育阶段表达。通过 RNA 干扰（RNAi）敲低 OsOFP6 导致半矮秆，改变粒形，侧根变短。结果表明，OsOFP6 干扰了生长素对侧根生长和起始的调节，因为在 IAA（吲哚-3-乙酸）处理下，RNAi 植物的侧根密度增加。OsOFP6 还影响极性生长素运输，这可以通过 RNAi 和 OsOFP6 过表达（OE）植物对 N-1-萘基苯甲酰胺（NPA）处理的不同反应来证明。此外，在干旱条件下，OE 系表现出比 RNAi 系较慢的水分损失和较少的 H2O2 积累，而 RNAi 系表现出较快的水分损失和较高的 H2O2，这意味着 OsOFP6 可能在水稻中赋予了抗旱性和耐旱性。此外，在冷处理下，OE 和 RNAi 系表现出较低和较高的相对电导率（REC），这表明 OsOFP6 在应对冷胁迫方面的重要作用。这些结果为卵形家族蛋白的多种功能提供了新的见解。
