A HELPING HAND: USING MICROBES TO AID PLANTS IN THE RECOVERY FROM FLOODING AND DROUGHT STRESS

Abstract

Increasing flooding and drought events negatively impact food security amid a growing population. Despite being on opposite sides of the water availability spectrum, flooding and drought are similar in response to one another and can be understood along a singular model. Knowledge of the recovery from these stresses is limited, but evidence suggests that post-flooding recovery shares commonalities with drought stress. Plants, in both scenarios, encounter analogous challenges such as reactive oxygen species (ROS) accumulation and water loss, and the microbiome can potentially aid in ameliorating these challenges. In exploring alterations in the microbiome under flooding and drought stress, it was found that flooding increases the abundance of anaerobic bacteria, notably Desulfobacteria and Firmicutes, and lowers the abundance of Actinobacteria and Proteobacteria, whereas drought increases monoderm bacterial families. During flooding and drought, plants also undergo significant morphological changes that change their ability to associate with the microbiome. Aerenchyma can cause a decrease in association ability by decreasing cortical cells available, whereas root hairs can increase this ability. Furthermore, the microbiome has the potential of being used as a tool to alleviate stress-induced shortcomings in plants functioning, by producing ABA, proline, and ACC-deaminase and stimulating root hair growth. By exploring these factors in the response to flooding and drought in the soil and plants, and investigating the role of the microbiome in ameliorating challenges encountered during these stresses, this review contributes to existing research on sustainable agricultural practices.