Redox homeostasis of cereals during acclimation to drought

Abiotic stresses are responsible for nearly 90% of all yield losses, around 40% of which are due to drought. Most cereal crops, the mainstay of agricultural production in many countries, are sensitive to drought. Plant resistance to drought is the result of numerous stress-protective systems, among which the antioxidant system occupies a special place. This review considers the causes of increased reactive oxygen species (ROS) generation in plants under water deficit, as well as their involvement in drought signal transduction. Examples of the involvement of antioxidant system components in cell signaling processes are considered. It is noted that antioxidants, in particular, are involved in signaling through changes in sulfhydryl homeostasis (RSH, RS-SR, and RSOH) and glutathionylation mode of specific proteins. Particular attention is paid to the contribution of specific enzymatic and low-molecular-mass antioxidants in the protection of various types of cereals from oxidative stress caused by drought. The role of compounds that are not classical antioxidants, such as proline, polyamines, sugars in protection against oxidative damage is considered. The review critically analyzes data on the relationship between the status of antioxidant system and drought resistance of cereals. It also briefly discusses the improvement of antioxidant system of plants through the transformation of genes of appropriate enzymes or transcription factors.