ABSTRACT
Plants are affected by abiotic stresses in different ways, which result in altered growth, development and physiology of the plant. All plants respond to stress signals such as drought, pathogens, heavy metals, salinity and heat, and produce various metabolites to adjust their metabolism. However, it is very important to develop low-cost strategies in order to manage these stresses in plants. Soil microbes possess wide properties such as increasing plant growth and productivity by establishing beneficial relationships with them and surviving under extreme conditions. They promote plant growth through increasing hormones and metabolite production as well as enhancing nutrient uptake. Plant-growth promoting rhizobacteria (PGPRs) acquire mechanisms to ameliorate different abiotic stresses such as heavy metals, drought, salinity, temperature, etc. Some of the stress-tolerant species include Bacillus, Pseudomonas alacaligenes, P. fluorescens, P. aeruginosa, Methylobacterium, Burkholderia, and so on. Apart from bacterial species, many fungi (endophytic/mycorrhizal) contribute to the adaptation of plants to abiotic stresses. Many fungal isolates of Trichoderma alleviate drought and salinity stresses within plants. Other than this, arbuscular mycorrhizal fungi stimulate nutrient uptake (calcium, phosphorus, magnesium, nitrogen) and accumulation of a wide variety of metabolites such as antioxidants, phenols, polyamines, betaines, proline, etc. Plants positively interact with micro-organisms (both bacteria and fungi) in order to alleviate abiotic stresses and improve their overall development.
