Drought Stress Mitigation in Plants: Ion Homeostasis, ABA Signaling, and Proline Accumulation

Ion homeostasis is a vital mechanism for mitigating drought-induced damage in plants. Drought results in disturbances in the balance of anions and cations, which disrupts water transportation in the plasma membrane and tonoplast. This, in turn, causes fluctuations in turgor pressure in guard cells, culminating in stomatal closure. Abscisic acid (ABA), which is rapidly synthesized in response to drought, modulates stress responses and initiates signaling cascades. ABA facilitates potassium ion efflux from guard cells, leading to stomatal closure, and stimulates proline accumulation. According to Verslues and Bray (2006), proline is one of the most widely distributed compatible solutes that accumulates in plants during adverse environmental conditions and plays a pivotal role in enhancing plant stress tolerance. Proline has diverse functions in adaptation, recovery, and signaling in plants when combating stress.