Lenka Sangram K, Muthusamy Senthilkumar K, Chinnusamy Viswanathan, Bansal Kailash C
ICAR-National Research Centre on Plant Biotechnology, Indian Agricultural Research Institute, New Delhi, 110012, India.
TERI-Deakin NanoBiotechnology Centre, The Energy and Resources Institute, New Delhi, 110003, India.
Mol Biotechnol. 2018 May;60(5):350-361. doi: 10.1007/s12033-018-0076-5.
Abscisic acid (ABA) plays an important role in plant development and adaptation to abiotic stresses. The pyrabactin resistance-like (PYL) gene family has been characterized as intracellular ABA receptors in Arabidopsis. We describe here the functional characterization of PYL3 ABA receptor from a drought-tolerant rice landrace Nagina 22 (N22). The induced expression level of the PYL3 transcript was observed in the N22 under different stress treatments, including cold, drought, high temperature, salt and ABA. In contrast, the expression of PYL3 was down-regulated in drought-susceptible rice cv. IR64 in response to above stresses. C-terminal GFP translational fusion of OsPYL3 was localized to both cytosol and nucleus explaining in part functional conservation of PYL protein as ABA receptor. Arabidopsis transgenic lines overexpressing OsPYL3 were hypersensitive to ABA suggesting ABA signaling pathway-dependent molecular response of the OsPYL3. Further, constitutive overexpression of OsPYL3 in Arabidopsis led to improved cold and drought stress tolerance. Thus, OsPYL3 identified in this study could be a good candidate for genetic improvement of cold and drought stress tolerance of rice and other crop plants.
脱落酸（ABA）在植物发育及适应非生物胁迫过程中发挥着重要作用。拟南芥中的类吡唑啉酮抗性（PYL）基因家族已被鉴定为细胞内ABA受体。在此，我们描述了来自耐旱水稻地方品种Nagina 22（N22）的PYL3 ABA受体的功能特性。在不同胁迫处理下，包括冷、干旱、高温、盐和ABA处理，N22中PYL3转录本的诱导表达水平被观察到。相比之下，在干旱敏感水稻品种IR64中，PYL3的表达在上述胁迫下被下调。OsPYL3的C末端GFP翻译融合定位于细胞质和细胞核，这部分解释了PYL蛋白作为ABA受体的功能保守性。过表达OsPYL3的拟南芥转基因株系对ABA高度敏感，表明OsPYL3存在依赖ABA信号通路的分子应答。此外，在拟南芥中组成型过表达OsPYL3导致其对冷和干旱胁迫的耐受性提高。因此，本研究中鉴定出的OsPYL3可能是水稻和其他作物遗传改良提高冷和干旱胁迫耐受性的良好候选基因。
