National Institute of Plant Genome Research, Aruna Asaf Ali Marg, JNU campus, New Delhi, 110067, India.
Institute of Plant Science and Resources, Okayama University, Kurashiki, 710-0046, Japan.
Sci Rep. 2017 Jun 21;7(1):4017. doi: 10.1038/s41598-017-03907-2.
Global transcriptome studies demonstrated the existence of unique plant responses under combined stress which are otherwise not seen during individual stresses. In order to combat combined stress plants use signaling pathways and 'cross talk' mediated by hormones involved in stress and growth related processes. However, interactions among hormones' pathways in combined stressed plants are not yet known. Here we studied dynamics of different hormones under individual and combined drought and pathogen infection in Arabidopsis thaliana by liquid chromatography-mass spectrometry (LC-MS) based profiling. Our results revealed abscisic acid (ABA) and salicylic acid (SA) as key regulators under individual drought and pathogen stress respectively. Under combined drought and host pathogen stress (DH) we observed non-induced levels of ABA with an upsurge in SA and jasmonic acid (JA) concentrations, underscoring their role in basal tolerance against host pathogen. Under a non-host pathogen interaction with drought (DNH) stressed plants, ABA, SA and JA profiles were similar to those under DH or non-host pathogen alone. We propose that plants use SA/JA dependent signaling during DH stress which antagonize ABA biosynthesis and signaling pathways during early stage of stress. The study provides insights into hormone modulation at different time points during combined stress.
全球转录组研究表明，在联合胁迫下存在独特的植物反应，而在单一胁迫下则不会出现这些反应。为了应对联合胁迫，植物利用信号通路和激素介导的“串扰”，这些激素涉及胁迫和生长相关过程。然而，在联合胁迫下，激素途径之间的相互作用尚不清楚。在这里，我们通过基于液相色谱-质谱（LC-MS）的分析方法研究了拟南芥在单一和联合干旱和病原菌感染下不同激素的动态变化。我们的研究结果表明，在单一干旱和病原菌胁迫下，脱落酸（ABA）和水杨酸（SA）分别是关键调节因子。在联合干旱和病原菌胁迫（DH）下，我们观察到 ABA 水平没有诱导，SA 和茉莉酸（JA）浓度上升，这强调了它们在基础耐寄主病原菌方面的作用。在与干旱的非寄主病原菌相互作用（DNH）下，ABA、SA 和 JA 的图谱与 DH 或非寄主病原菌单独作用下的图谱相似。我们提出，植物在 DH 胁迫下利用 SA/JA 依赖的信号通路，拮抗胁迫早期 ABA 的生物合成和信号通路。该研究为联合胁迫下不同时间点激素调节提供了新的见解。
