Application of Endophytic Microorganisms for Alleviation of Abiotic Stresses in Crop Plants

Abstract

A majority of the plants studied in natural ecosystems are symbiotic with microorganisms that either reside entirely (endophytes) or partially within plants. These microorganisms express different associations ranging from mutualism to parasitism. These symbiotic relationships appear to impart tolerance to various types of abiotic stresses such as heat, drought, salinity, heavy metals, etc. and sometimes may be responsible for the survival of both plant hosts and microbial symbionts in high stress habitats. The amelioration of the abiotic stresses by the endophytes assumes increasing significance in the light of rapidly changing global climate, which is likely to face frequent incidences of extreme weather conditions like high temperature, droughts, etc. To compensate the loss in crop productivity due to vagaries of nature and depleting areas of cultivable land, the application of endophytic microorganisms in agriculture is seen as a potential and ecologically sound means of maintaining profitability and sustainability in crop production. Apart from providing tolerance to abiotic stresses, majority of the endophytes are also known to confer tolerance to biotic stresses such as diseases, pests, etc. The endophytic microorganisms have also found application in remediation of heavy metal contaminated sites or polluted soils through phytoremediation. Here, we describe the role of endophytic microorganisms in alleviation of abiotic stresses in plants and the different ways by which this symbiosis can potentially mitigate the impacts of climate change and anthropogenic activities on crop plants.