Plant Genetic Engineering Laboratory, Department of Biotechnology, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India.
Department of Biotechnology, PSG College of Technology, Coimbatore, Tamil Nadu, India.
World J Microbiol Biotechnol. 2020 Jun 19;36(7):92. doi: 10.1007/s11274-020-02868-5.
All plants harbor many microbial species including bacteria and fungi in their tissues. The interactions between the plant and these microbes could be symbiotic, mutualistic, parasitic or commensalistic. Mutualistic microorganisms are endophytic in nature and are known to play a role in plant growth, development and fitness. Endophytes display complex diversity depending upon the agro-climatic conditions and this diversity could be exploited for crop improvement and sustainable agriculture. Plant-endophyte partnerships are highly specific, several genetic and molecular cascades play a key role in colonization of endophytes in host plants leading to rapid changes in host and endophyte metabolism. This results in the accumulation of secondary metabolites, which play an important role in plant defense against biotic and abiotic stress conditions. Alkaloids are one of the important class of metabolites produced by Epichloë genus and other related classes of endophytes and confer protection against insect and mammalian herbivory. In this context, this review discusses the evolutionary aspects of the Epichloë genus along with key molecular mechanisms determining the lifestyle of Epichloë endophytes in host system. Novel hypothesis is proposed to outline the initial cellular signaling events during colonization of Epichloë in cool season grasses. Complex clustering of alkaloid biosynthetic genes and molecular mechanisms involved in the production of alkaloids have been elaborated in detail. The natural defense and advantages of the endophyte derived metabolites have also been extensively discussed. Finally, this review highlights the importance of endophyte-arbitrated plant immunity to develop novel approaches for eco-friendly agriculture.
所有植物的组织中都栖息着许多微生物物种，包括细菌和真菌。植物与这些微生物之间的相互作用可能是共生的、互利的、寄生的或共生的。互利共生微生物本质上是内生的，已知它们在植物的生长、发育和适应能力方面发挥作用。内生菌表现出复杂的多样性，这取决于农业气候条件，这种多样性可以被利用来改善作物和可持续农业。植物-内生菌的伙伴关系是高度特异的，几个遗传和分子级联在内生菌在宿主植物中的定植中起着关键作用，导致宿主和内生菌代谢的快速变化。这导致次生代谢物的积累，次生代谢物在植物对生物和非生物胁迫条件的防御中起着重要作用。生物碱是麦角菌属和其他相关内生菌类产生的重要代谢物之一，能保护植物免受昆虫和哺乳动物的侵害。在这方面，本综述讨论了麦角菌属的进化方面，以及决定麦角菌内生菌在宿主系统中生活方式的关键分子机制。提出了一个新的假设，以概述麦角菌在冷季草中定植的初始细胞信号事件。详细阐述了生物碱生物合成基因的复杂聚类和参与生物碱产生的分子机制。还广泛讨论了内生菌衍生代谢物的天然防御和优势。最后，本文综述了内生菌介导的植物免疫的重要性，以开发环保农业的新方法。
