Early warning signals of drought induced oxidative stress and genotype tolerance. A review

Drought was shown to cause harm to plants - reducing growth, physiological activity, reproduction, and productivity. In an agricultural aspect, "drought" means not having sufficient soil moisture required by plants to maintain their normal growth and development throughout the life cycle. Drought is known as the most common environmental stress affecting plants through induced oxidative stress. Being sessile organisms, plants have developed various strategies to cope with water scarcity - escape, avoidance, and tolerance. In this review, we discuss the drought as an environmental factor, oxidative stress induced by drought, and some commonly used endpoints such as MDA and H2O2 for the evaluation of the magnitude of drought stress as well as the contribution of both Proline and HSP70/chaperone involved in the formation of plants tolerance to drought-induced stress. Based on the available data in the literature and our own results, it was shown that both biochemical endpoints MDA and H2O2 could play a dual role - as indicators of the magnitude of drought-induced stress, as well as markers of tolerance to drought. The great contribution of Pro and HSP70 for the formation of increased drought tolerance in plants was analyzed. The dynamics of cytoplasmic HSP70 chaperone levels in bean lines with different resistance to water deficiency revealed that HSP70 family proteins are one of the main components of plant stress tolerance. It could be said that these simple and not expensive endpoints could be successfully applied as early warning signals for revealing drought-induced stress and plants tolerance.