Department of Botany, Savitribai Phule Pune University, Pune-411007, India.
Department of Microbiology, Savitribai Phule Pune University, Pune-411007, India.
Funct Plant Biol. 2020 Sep;47(10):880-890. doi: 10.1071/FP20035.
Plants get phosphorus, water and other soil nutrients at the cost of sugar through mycorrhizal symbiotic association. A common mycorrhizal network (CMN) - a dense network of mycorrhizal hyphae - provides a passage for exchange of chemicals and signals between the plants sharing CMN. Mycorrhisation impact plants at hormonal, physiological and metabolic level and successful symbiosis also regulates ecology of the plant rhizosphere. Apart from nutritional benefits, mycorrhisation provides an induced resistance to the plants known as mycorrhiza induced resistance (MIR). MIR is effective against soil as well as foliar pathogens and pest insects. In this review, molecular mechanisms underlying MIR such as role of phytohormones, their cross talk and priming effect are discussed. Evidence of MIR against economically important pathogens and pest insects in different plants is summarised. Mycorrhiza induces many plant secondary metabolites, many of which have a role in plant defence. Involvement of these secondary metabolites in mycorrhisation and their putative role in MIR are further reviewed. Controversies about MIR are also briefly discussed in order to provide insights on the scope for research about MIR. We have further extended our review with an open ended discussion about the possibilities for transgenerational MIR.
植物通过与菌根共生体的共生关系，以糖为代价获取磷、水和其他土壤养分。一个常见的菌根网络（CMN）——菌根菌丝的密集网络——为共享 CMN 的植物之间的化学物质和信号交换提供了通道。菌根化会影响植物的激素、生理和代谢水平，成功的共生还会调节植物根际的生态。除了营养益处外，菌根化还为植物提供了一种称为菌根诱导抗性（MIR）的诱导抗性。MIR 对土壤和叶部病原体以及害虫昆虫都有效。在这篇综述中，讨论了 MIR 的分子机制，如植物激素的作用、它们的串扰和引发效应。总结了 MIR 对不同植物中重要经济病原体和害虫昆虫的证据。菌根诱导许多植物次生代谢物，其中许多在植物防御中起作用。还进一步综述了这些次生代谢物在菌根化和 MIR 中的潜在作用。还简要讨论了关于 MIR 的争议，以便深入了解关于 MIR 的研究范围。我们还通过对跨代 MIR 的可能性进行开放式讨论，进一步扩展了我们的综述。
