CORONATINE: A POTENTIAL PHYTOTOXIN FOR INCREASING THE TOLERANCE OF PLANTS TO DROUGHT STRESS

Abstract

Drought and water deficiency are the leading factors that negatively threaten plant growth and development, resulting in significant yield losses in agricultural production. Severe drought events expected because of global warming reveal that serious steps should be taken to enhance the drought tolerance of agricultural crops. Coronatine (COR), a chlorosis-inducing and non-host-specific phytotoxin secreted by the pathogen Pseudomonas syringae, is structurally and functionally similar to jasmonates, but it is far more active as a plant growth regulator. Therefore, many studies have been conducted to understand the positive effect of COR application on drought stress tolerance in plants. This review assesses the potential of COR for improving plant drought tolerance by examining previous studies that investigated the effect of exogenously applied COR on antioxidant enzyme activities of plants exposed to osmotic stress simulated by polyethylene glycol PEG application or by not providing water. In addition, it was evaluated whether COR could have a dose-dependent effect on the antioxidant enzyme activities of plants under drought stress. According to the findings of the reviewed studies, COR treatment enhanced the plant drought tolerance by increasing the activity of antioxidant enzymes.