Drought: Sensing, signalling, effects and tolerance in higher plants

Drought can be considered as a cocktail of multiple stressful conditions that contribute to osmotic and ionic imbalance in plants. Considering that water is vital for plant life, the very survival of the plant becomes questionable during drought conditions. Water deficit affects a wide spectrum of morpho-physiological phenomena restricting overall plant growth, development and productivity. To evade such complications and ameliorate drought-induced effects, plants have a battery of various defence mechanisms. These mechanisms can vary from stomatal adjustments to osmotic adjustments and antioxidant metabolism to ion regulations. In this review, we critically evaluate how drought is perceived and signalled through the whole plant via abscisic acid mediated pathways. Additionally, the impact of drought on photosynthesis, gas exchange variables and reactive oxygen species pathway was also reviewed, along with the reversal of these induced effects through associated morpho-physiological counter mechanisms.

Automated summary

Drought is a combination of multiple stressful conditions that disrupt osmotic and ionic balance in plants, leading to impacts on overall plant growth, development, and productivity. Plants have various defense mechanisms to mitigate the effects of drought, including stomatal adjustments, osmotic adjustments, antioxidant metabolism, and ion regulations, which can help alleviate the damage caused by water deficit.