Phytohormonal modulation of the drought stress in soybean: outlook, research progress, and cross-talk

Abstract

Phytohormones play vital roles in stress modulation and enhancing the growth of plants. They interact with one another to produce programmed signaling responses by regulating gene expression. Environmental stress, including drought stress, hampers food and energy security. Drought is abiotic stress that negatively affects the productivity of the crops. Abscisic acid (ABA) acts as a prime controller during an acute transient response that leads to stomatal closure. Under long-term stress conditions, ABA interacts with other hormones, such as jasmonic acid (JA), gibberellins (GAs), salicylic acid (SA), and brassinosteroids (BRs), to promote stomatal closure by regulating genetic expression. Regarding antagonistic approaches, cytokinins (CK) and auxins (IAA) regulate stomatal opening. Exogenous application of phytohormone enhances drought stress tolerance in soybean. Thus, phytohormone-producing microbes have received considerable attention from researchers owing to their ability to enhance drought-stress tolerance and regulate biological processes in plants. The present study was conducted to summarize the role of phytohormones (exogenous and endogenous) and their corresponding microbes in drought stress tolerance in model plant soybean. A total of n=137 relevant studies were collected and reviewed using different research databases.

Functional Characterization of the Soybean Glycine max Actin Depolymerization Factor GmADF13 for Plant Resistance to Drought Stress

“…Due to its rich nutritional content, foods processed from soybeans have become one of the most favored sources of sustenance [ 64 ]. Despite the annual increase in soybean production, environmental stress remains a significant factor affecting soybean yield [ 6 ]. Among various environmental stresses, drought is one of the most impactful abiotic stressors on soybean quality [ 5 ].…”

“…Previous studies have shown that drought stress reduces soybean germination rates and net photosynthetic rates, leading to significant decreases in biomass accumulation, pod set rates, and per plant grain yield [ 65 , 66 ]. Given its importance as a staple food crop, research on soybean drought resistance has garnered extensive attention [ 6 ].…”

“…Drought stress, one of the major abiotic stress factors, exerts significant impacts on plant growth and development at physiological, biochemical, and molecular levels [ 5 ]. It poses a major threat to agriculture worldwide, hindering food security [ 6 , 7 ]. Therefore, the development of stress-tolerant crops with stable yields under adverse conditions is of great importance [ 8 , 9 ].…”