Priming and cross-adaptation of plants to abiotic stresses: state of the problem and prospects

Abstract

The review is devoted to the current state and prospects of research on the problem of plants priming and cross-adaptation to abiotic stress factors — mainly drought and high temperature. These studies are becoming increasingly relevant due to global climate change, as they reveal new approaches to increasing the crops resistance to stressors. The key link in this case is the formation of the so-called stress memory (priming) under the influence of moderate stress, which allows the plant to activate protective mechanisms faster and more effectively under the effect of the next harder stress of the same or a different nature (cross-adaptation) and thereby mitigate its impact compared to non-primed plants. In this regard, information on signaling systems that participate in the perception of a stress factor by a plant and trigger protective mechanisms through multi-cascade networks is considered. The results of experiments on priming plants with high temperature or drought at the beginning of the growing season to the action of these stressors at later development stages, as well as examples of cross-adaptation, when priming with drought increased thermotolerance and vice versa, are given. Possible mechanisms of stress memory formation and retention within one generation and its transference to subsequent generations (transgenerational stress memory) are briefly considered. At the same time, one of the unsolved problems remains the correctness of extrapolation results obtained in laboratory or controlled conditions to the practice of growing plants in the field. Certain side effects of priming should also be considered, as priming may cause some negative effects on plant physiology and productivity. Therefore, it is necessary to test whether the primed plants will perform as well as the control if the stress will not happen.