Roles of Fungal Endophytes and Viruses in Mediating Drought Stress Tolerance in Plants

Abstract

Various biotic and abiotic stresses can hamper crop productivity and thus pose threats to global food security. Sustainable agricultural production demands for the use of safer and eco-friendly tools and inputs in farm production. In addition to plant growth-promoting bacteria and mycorrhizal fungi, endophytic fungi can also help plant mitigate or reduce the effect of stresses. Another less well-known is the use of viruses that provide benefit to plants facing growth challenges due to stress. Studies suggest that fungal endophyte and virus could be important candidate and economically and ecologically sustainable means for protecting plants from stress condition. To exploit their benefits, a thorough understanding of the interaction of host-beneficial microbes obtained by scientifically sound experiments with robust statistical analysis is crucial. Another important aspect is to gather available information in a consolidated form that may provide the framework for future investigation, which is currently lacking. In this review, at first, we presented the impacts of drought in crop production worldwide. Then, we attempted to present briefly the various physiological, biochemical and molecular strategies that plant uses to cope with drought stresses. Major part of this review has been reserved to discuss the recent literatures regarding the roles of fungal endophyte and beneficial viruses in mitigating the impact of drought on plants in order to gain more insight into the microbe mediated plant abiotic stress tolerance. In addition, we summarised the mechanism of fungus and virus mediated drought tolerance in plants. At the end, we discussed about the research gap and highlighted points which need prime emphasis in harnessing the beneficial effects of microbes in sustainable agriculture. This review would be helpful for the researcher who work on this field to develop future research plans to better understand the nature plant-microbe interactions and application of beneficial microorganisms in eco-friendly crop cultivation.