Rhizospheric soil is enriched with diverse microbial communities, which
give rise to sophisticated plant-microbes interactions via chemical communication. The
bacteria attain communication through quorum sensing and lead to biofilm formation,
developing connections between the cell density, and altering gene expression. Such
processes include diffusion and accumulation of signal molecules such as autoinducer
i.e. acyl-homoserine lactones, Autoinducer-2 (AI-2), QS pheromone, etc. in the
environment and trigger the expression of the gene. Due to increment in cell density,
bacteria produce the substances that inhibit the growth of pathogens, fix nitrogen and
optimize nodule formation. Moreover, the adaptability of microbial communities under
stress conditions directly/indirectly was correlated with host plant growth. The plants
and soil microorganisms equally face the abiotic stresses and may cause environmental
tolerance and adaptability via complex physiological and cellular mechanisms. The
recent knowledge of the plant-microbe relationship and their communication
mechanisms can be helpful in the development and commercialization of agricultural
practices to improve desired crop health and productivity under various abiotic and
biotic stresses. This chapter explores such habiting microbial communications in
rhizosphere attributing to soil environment in various means.
Keywords: Abiotic Stress, Acyl-Homoserine Lactones, Autoinducers, Microbial Communication, Nitrogen Fixation, Nutrient Cycle, PGPR, Pheromones, Plant - Microbes Interaction, Quorum Sensing, Rhizobia, Rhizosphere, Secondary Metabolites, Signalling Molecules, Symbiosis.
