Diversity of Plant Root Associated Microbes: Its Regulation by Introduced Biofilms

DOI: 10.1007/978-81-322-1287-4_13 In book: Plant Microbe Symbiosis- Fundamentals and Advances, Chapter: 13.Diversity of plant root associated microbes: its regulation by introduced biofilms, Publisher: Springer India, Editors: Naveen Kumar Arora, pp.351-372

ABSTRACT Microorganisms use dormancy as a tactic to evade from unfavourable
fluctuations of environment conditions, which results in a voluminous soil seed
bank of coexisting species. This has now been well proven with the advent of
molecular techniques. Sporadic resuscitation of the dormant microbes contributes
to maintain ecosystem functioning. The interchange of dormant and active stages
aids vast number of species to coexist whilst maintaining persistent populations
amidst constant evolutionary pressure. This interchange is a response to dynamic
biotic and abiotic factors in the soil environment. Amongst factors deciding this switch, host factor is well documented in the case of plant-associated microorganisms.
In addition to the responsive interchange in the fluctuating environments, a spontaneous
interchange takes place in stable environments, which is determined by quorum
sensing (QS) that leads to emergence of subpopulations. This is theoretically known
as “kin selection” or the promotion of species depending on the degree of genetic
relatedness amongst the individual organisms. All in all, those mechanisms
resulted in a lesser number of individuals in active stage, due to ever-increasing
adverse conditions imposed on the environment. This has caused to collapse
in many ecosystems. However, recent research shows that if developed
beneficial microbial communities in biofilm mode would be introduced to the
soil, they can increase the emergence of soil microbial diversity, favouring surfacing
of subpopulations of beneficial species. It is now evident that the biofilm actions
break dormancy of the microbial seed bank for the increased resuscitation of the
dormant cells.

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