Endophytic Microbiome-Assisted Drought Tolerance in Plants

Agricultural productivity is constantly influenced by several factors such as urbanization, less availability of cultivable land, lack of sufficient automation, and abiotic and biotic stresses. Global climatic conditions significantly influenced the annual precipitation. Thus, decreased rainfalls, increased dry spells, soil salinity, and high temperature considerably affect agriculture productivity. On the other hand, the ever-burgeoning human population demands more food from the limited resources, putting much pressure on agricultural productivity. Drought stress causes several morphological, structural, biochemical, and molecular changes in plants. Plants to endure drought stress synthesize several secondary metabolites, reactive oxygen species, and module hormone production and induce several drought resistance genes. However, not all plants respond to the drought stress in the same magnitude. Most of the cultivable crops are drought-sensitive. Thus, the scientific community adopted several methods to improve drought tolerance in crop plants. Due to the constraints of agronomical practices, genetic engineering (GE), and marker-assisted breeding approaches, scientists recently developed a spark of interest in improving the crop plant’s performance under extreme environmental conditions with the natural plant-associated microbiome. The plant-associated microbiome may improve drought stress tolerance through multiple pathways, such as improving the mineral nutrition absorption, phytohormone production, ACC deaminase activity, and root system, producing exopolysaccharides, and triggering the systemic induced resistance. The chapter discussed the detailed mechanism of the endophytic microbiome colonization process, functional traits of the microbiome, and drought tolerance mechanism of the endophytic microbiome with some examples.