Actinomycetes as mitigators of climate change and abiotic stress

Abstract

Agricultural productivity is affected worldwide due to anthropogenic and climate change-induced abiotic stresses, posing a threat to food security. Use of microorganisms for abiotic stress management in agriculture is emerging as economically viable and environmental-friendly option. Actinomycetes, the Gram-positive bacteria with filamentous structure that are common associates of plants (as rhizosphere inhabitants and as plant endophytes), are receiving attention for their potential application in stressed ecosystems. Many actinomycetes exhibit plant growth-promoting (PGP) properties including indole acetic acid (IAA) production, phosphate solubilization, siderophore production, biocontrol of phytopathogens, and 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity. Besides, they can grow under diverse stress conditions such as moisture stress, high temperature, salinity, alkalinity, and wide pH range. Recently, many reports have documented the role of actinomycetes in alleviating salinity and drought stress in crop plants. However, there is a need to further strengthen the research to explore their potential to improve plant productivity under diverse environmental stress conditions by conducting extensive pot and field trials and to understand the underlying mechanisms.