Diversity of plant root associated microbes: Its regulation by introduced biofilms

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 have 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 sustainability 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.