Department of Agricultural Microbiology, Directorate of Natural Resources Management, Tamil Nadu Agricultural University, Coimbatore, 641 003, India.
Department of Agricultural Microbiology, Directorate of Natural Resources Management, Tamil Nadu Agricultural University, Coimbatore, 641 003, India.
Microbiol Res. 2020 Jan;231:126355. doi: 10.1016/j.micres.2019.126355. Epub 2019 Oct 17.
In the changing scenario of agriculture, plants are exposed to various biotic and abiotic stresses. Induction of both constitutive and inducible defense systems was noticed in plants exposed to stress. As a major defense response, production of phenolics and superoxide radicals quenching enzymes is accelerated in plants under stress. These metabolites production intensified further when arbuscular mycorrhizal fungi (AMF) infected plants are subjected to stress. With this background, we conducted experiments to explore the impacts of Glomus intraradices and Rhizobium on the stimulation of defense in blackgram against Spodoptera litura. Uninoculated plants accumulated considerable quantity of defense metabolites like phenolics, lignin and superoxide radicals quenching enzymes such as superoxide dismutase, peroxidase, catalase, phenylalanine ammonium lyase, and polyphenol oxidase constitutively. While production of these defense metabolites primed strongly due to G. intraradices inoculation. These defense responses augmented further when G. intraradices colonized plants were exposed to S. litura. Though the combined inoculation with G. intraradices and Rhizobium improved the defense response, the effect was more pronounced due to single inoculation with G. intraradices. Results of in vitro leaf feeding bioassay showed that the feeding capacity of S. litura reduced (36.32%) significantly due to feeding G. intraradices infected plants. These outcomes revealed that tolerance against S. litura in blackgram could be primed by mycorrhizal inoculation. This is the first report to state that G. intraradices besides improving nutrient use efficiency, also accelerates defense response in blackgram against S. litura. Hence, AMF could be recommended as a bioprotectant against S. litura in blackgram.
在农业不断变化的背景下，植物面临着各种生物和非生物胁迫。研究发现，植物在受到胁迫时会诱导产生组成型和诱导型防御系统。作为主要的防御反应，植物在受到胁迫时会加速酚类物质和超氧自由基清除酶的产生。当被丛枝菌根真菌（AMF）感染的植物受到胁迫时，这些代谢物的产生会进一步加剧。在此背景下，我们进行了实验，以探索 Glomus intraradices 和 Rhizobium 对豇豆抵抗斜纹夜蛾防御的刺激作用。未接种的植物会持续积累大量防御代谢物，如酚类物质、木质素和超氧自由基清除酶，如超氧化物歧化酶、过氧化物酶、过氧化氢酶、苯丙氨酸解氨酶和多酚氧化酶。而当接种了 G. intraradices 后，这些防御代谢物的产生会被强烈地激发。当 G. intraradices 定殖的植物受到 S. litura 的侵害时，这些防御反应进一步增强。虽然同时接种 G. intraradices 和 Rhizobium 会提高防御反应，但单独接种 G. intraradices 的效果更为显著。体外叶片喂养生物测定的结果表明，由于喂食了感染了 G. intraradices 的植物，斜纹夜蛾的取食能力显著降低（36.32%）。这些结果表明，通过接种丛枝菌根真菌可以使豇豆对斜纹夜蛾产生耐受性。这是第一个报道表明，G. intraradices 除了提高养分利用效率外，还能加速豇豆对 S. litura 的防御反应。因此，AMF 可以作为防治豇豆斜纹夜蛾的生物保护剂。
