Department of Agricultural Sciences, Biotechnology and Food Science, Cyprus University of Technology, Arch. Kyprianos 30, 3036, Limassol, Cyprus.
Department of Agricultural Sciences, Biotechnology and Food Science, Cyprus University of Technology, Arch. Kyprianos 30, 3036, Limassol, Cyprus.
Plant Physiol Biochem. 2018 Sep;130:658-662. doi: 10.1016/j.plaphy.2018.08.018. Epub 2018 Aug 13.
Plant response to imposition of biotic and abiotic stresses by inducing their defense mechanisms, with the production of reactive oxygen species (ROS) representing a major defense response. The present work examined the simultaneous impact of two key stress factors, drought and spider mite attack (Tetranychus urticae) in Medicago truncatula plants. Hydrogen peroxide (HO), lipid peroxidation (MDA content) and proline content in well-watered and drought-stressed leaves infested by spider mites along with neighboring leaves were examined in order to investigate the local and systemic effect of the two stresses on the antioxidant and osmoprotective response. High levels of lipid peroxidation were recorded in plants under drought stress and plants under combined drought stress and spider mite feeding compared with control plants. Hydrogen peroxide biosynthesis was significantly induced in plants under drought and spider mite attack, with highest levels detected in the feeding leaf (local response). Proline was accumulated in drought stressed-plants, with the highest levels observed in plants exposed to a combination of drought stress and mite feeding. RT-qPCR expression analysis of key genes implicated in ROS metabolism (PAO, DAO, AOX, CuZnSOD, FeSOD, MnSOD) and proline biosynthesis (P5CR, P5CS) pointed to different patterns of regulation between abiotic and biotic stress, as well as their combination. Exposure of plants to both drought stress and attack by spider mites mainly affected the local antioxidant and osmoprotective response of Medicago truncatula, highlighting the relative significance of drought-induced phenomena in combined drought/mite infestation stress responses.
植物通过诱导防御机制来应对生物和非生物胁迫，其中活性氧（ROS）的产生代表了主要的防御反应。本研究同时考察了两个关键胁迫因素——干旱和叶螨攻击（Tetranychus urticae）对蒺藜苜蓿植株的影响。检测了在有叶螨取食和相邻叶片的情况下，水分充足和干旱胁迫叶片中的过氧化氢（HO）、脂质过氧化（MDA 含量）和脯氨酸含量，以研究这两种胁迫对抗氧化和渗透调节反应的局部和系统影响。与对照植株相比，在干旱胁迫下和同时受到干旱胁迫和叶螨取食的植株中记录到高水平的脂质过氧化。在干旱和叶螨取食的植株中，过氧化氢的生物合成明显受到诱导，在取食叶片（局部反应）中检测到的水平最高。脯氨酸在干旱胁迫植株中积累，在同时受到干旱胁迫和叶螨取食的植株中观察到的水平最高。涉及 ROS 代谢（PAO、DAO、AOX、CuZnSOD、FeSOD、MnSOD）和脯氨酸生物合成（P5CR、P5CS）的关键基因的 RT-qPCR 表达分析表明，非生物和生物胁迫以及它们的组合之间存在不同的调节模式。植物同时受到干旱胁迫和叶螨攻击的影响主要影响了蒺藜苜蓿的局部抗氧化和渗透调节反应，突出了干旱诱导现象在干旱/叶螨复合胁迫反应中的相对重要性。
