Drought Stress: Responses and Mechanism in Plants

The function of water for plants is crucial, including playing the roles in metabolic reactions. The aims of this article are to give information on the effects of drought stress on plant morphology, physiology, and biochemistry, as well as mitigation methods in drought stress management for plant production. Plants manage drought stress using a mechanism, namely drought escape, drought avoidance and drought tolerance. Drought escape is the ability of plants to accelerate flowering or life cycle, drought avoidance is the ability of plants to reduce water loss and increase water absorption through morphological changes in the root system, drought tolerance is the plant adaptation to drought by changes in plant physiological and biochemical processes. Physiological changes that occur include closing the stomata and decreased photosynthesis. The biochemical responses include the synthesis of solute compounds as a form of osmotic adjustment in the cell called osmotic adjustment to reduce water loss from the cell. The biochemical indicators are the increased concentrations of abscisic acid (ABA), proline, and sugar (trehalose). ABA acts as a signal to stimulate stomatal closure to reduce the transpiration rate. Proline is an indicator of plants adapting to drought stress, playing a role in the osmotic adjustment of cells to retain in the cell. Trehalose is a compatible sugar acting as an osmoprotectant, it can maintain the integrity of cell membranes (water replacement) and form hydrogen bonds (water entrapment). Plants under drought stress conditions can adapt by making morphological, physiological, and biochemical responses by osmotic adjustment. These conditions need to be managed so that appropriate strategies and technologies are needed as mitigation measures.