Alleviating drought stress of crops through PGPR: Mechanism and application

Abstract

Crop productivity is severely affected by drought, and its incidence is predicted to enhance under environmental fluctuations and climate change throughout the world. Scarcity of water induced loss in crop growth as well as yields due to major changes in metabolic pathways and gene regulation. Innovative approaches using biochemical and molecular mechanisms increased our understanding of drought alleviation and its management. Previous researches have been focused on the alleviation of drought using rhizobacteria for sustainable agriculture. In recent years, drought stresses in the agriculture system have gained attention due to their deleterious impact on the crop production, protection, and soil health environment. Rhizobacteria perform an important role in the surface colonization of soil colloids and roots of the plant and facilitate proliferation in desired niche, while also improving soil fertility. Despite this fact, numerous papers have reported on growth-stimulating rhizobacteria, but insufficient evidence is available on the rhizobacterial-mediated mitigation of drought stress in soil system. Implications of climate change, namely, drought, would cause disturbance in plant nutrition and soil quality, and plant protection can be better appreciated via an improved understanding of plant microbe as well as soil microbe interaction. Understanding the involvement of various key regulators such as biochemical adjustment, genetic modifications, and molecular strategies will assist effectively for drought stress amelioration in environment-friendly and sustainable agriculture. The present article addresses the biochemical and molecular modification during stress situation in the alleviation of stress under plant soil system. Special consideration is given to plant growth-promoting rhizobacteria with drought tolerance and alleviation capability by the modification of their regulatory mechanisms.