Root Phenolics Profile Modulates Microbial Ecology of Rhizosphere

Abstract

Rhizosphere is a narrow zone of soil surrounding plant roots. Plants release an array of organic and inorganic compounds in rhizosphere to influence microbial community, manage soil herbivores, attract beneficial symbionts, alter chemical and physical properties of the soil, and hinder growth of competitor plants. Phenolic compounds are important plant secondary metabolites released in the rhizosphere. Chemically, plant phenolics are organic compounds of plant origin having one or more functional hydroxyl group bonded directly to aromatic hydrocarbon. In last few decades our understanding of phenolic compounds and their role in aboveground plant parts have increased tremendously. Relatively, our knowledge about phenolic compounds and their role in biology and ecology of rhizosphere is not very clear. Plants can alter amount as well as composition of phenolic compounds in rhizodeposits to bring about desirable changes in the micro-environment of rhizosphere. Profiles of phenolic compounds in plant are not only regulated by inherited genetic information but also influenced by environmental cues. The rhizosphere has significant influence on vigor and ecological fitness of their host plant. Understanding the role of phenolic compounds in rhizosphere will allow us to design and develop sustainable agriculture practices. The current chapter describes the role of root exudates component, particularly the phenolic compounds, on plant–microbe interaction and functioning of rhizosphere.