Drought Stress is a Global Problem in Sustainable Agriculture: Response of Plant, Role of Fungal Endophytes

Food will always be needed because of the expanding world population. By 2050, there may be more than 9.7 billion people in the world, which might result in a surge of up to 70% in the global food output (Castaneda et al., 2016; Abdelrahman et al., 2017). However the population is more than 65% relying completely on agriculture for their subsistence, this number can reach up to 90% in underdeveloped nations (Castaneda et al., 2016). Food security in all nations, but particularly in emerging nations, is seriously threatened by crop losses (Ghini et al., 2008; Chakraborty & Newton, 2011). Crop losses are primarily caused by pathogens and abiotic factors (Singla et al., 2016). Small land ownership and improper mechanization are both ongoing factors that affect agricultural productivity (Ahluwalia et al., 2021). Abiotic stress is one of the most significant constraints in agricultural production, principally in dry and semi-dry districts. It contains drought, temperature swings, excessive soil salinity, metal toxicity, and oxidative stresses (Fahad et al., 2017). These affect the sustainability of plants in natural and agricultural communities (McCartney & Lefsrud, 2018; Bhat et al., 2020). In recent decades never-before-seen climate change has made the consequences of these abiotic stresses worse (Fedoroff et al., 2010). The anthropogenic effects are deforestation, industrialization, agriculture, urbanization, and changes in the use of land caused the climate change (Suryanarayanan et al., 2018; Chandra et al., 2021). The rise of temperature and atmospheric carbon dioxide (CO₂) amount with variations in the timing of rain is the result of climate change (Chandra et al., 2021). In addition, the Intergovernmental Panel on Climate Change (IPCC) has explained that if anthropogenic activity keeps at its current rate, global temperatures might climb by up to 1.5ºC by the year 2052 (IPCC, 2018). This will create often and severe drought occurrences in several regions (Okunlola et al., 2017). Drought is the most important abiotic stress that inhibits crop productivity worldwide (Zolin & Rodrigues, 2015) and causes a 50–70% drop in the productivity of agriculture (Verma & Deepti, 2016). Also, about 700 million people will face the risk of relocation in 2030 due to drought stress (Jamieson et al., 2021). Water minorities through a reduction in rainfall and a rising density of arid terms produce drought circumstances (Mirajkar et al., 2019; Ahluwalia et al., 2021). Numerous negative impacts of drought stress on plants include decreasing plant biomass and photosynthesis and changes in hormone metabolism and enzyme function. Moreover, severe drought can reduce the yield of plants and increase plant mortality (Challinor et al., 2004; Stovall et al., 2019). Drought stress decreased output in a variety of crops by almost 70% (Kaur et al., 2008; Akram et al., 2013). Recent studies have emphasized the significance of plant-associated microbial communities in supporting the resistance and recovery of their host plants from abiotic stresses (Lata et al., 2018; Sadeghi et al., 2020).

This study focused on the impacts of fungal endophytes and drought stress in plants.