Overview of Microbial Associations and Their Role Under Aquatic Ecosystems

Abstract

Water plays a vital role in regulating the lives of living beings on earth. Life cannot be imagined without water. Aquatic plants inhabit the littoral or shallow water zones of waterbodies like river, ponds, lakes, and oceans. These plants exhibit a mutual coexistence, pathogenic infestation, commensalism, or in symbiotic association with the microbes. These plants also serve as powerful tools for removal of contaminants in the form of heavy metals in water and soil sediments. The phyllosphere consists of various microbes such as bacteria, viruses, protists, ecto- and endoparasites, nematodes, protozoa, etc. Although the zone between the microbes and roots of aquatic plants is not well defined in terms of nutrients due to their diffusion in water, still there exists a zone of interaction between them. Microbes coevolved with the plants for the fulfillment of their nutrient deficiencies in their fundamental niches. Thus, the aquatic micro biome plays a vital role in influencing and promoting the aquatic ecosystem. The plant–microbe interaction is also affected by the environment: both biotic and abiotic factors have a concomitant effect on the marine ecosystem, thereby leading to change at molecular and gene expression levels causing production of compounds by these microbial–host–environmental interactions. This chapter focuses on how the aquatic microbiomes influence the structure, growth of plants, and their diversity. It also encompasses the the molecular strategy adopted for production of metabolites and biofilm, siderophores, system of quorum sensing, cell to cell signaling, signal transduction, etc.