Morphological, physiological, and molecular components of the adaptive response to drought in the genus Quercus (Fagaceae)

The genus Quercus consisting of approximately 500 species is one of the dominant genera of woody plants in the Northern Hemisphere. The survival and distribution of Quercus species are profoundly influenced by extreme environmental conditions, including drought. To withstand drought stress, plants employ various adaptive strategies encompassing morphological, physiological, and molecular adaptive changes. This review aims to analyze and summarize the latest research on the adaptation of Quercus species to drought conditions, with a special focus on the species growing in Ukraine. The review explores the effects of drought on growth, productivity, physiological processes, biochemical responses, and molecular characteristics within the genus Quercus. Special attention is given to the impact of drought on photosynthetic activity, antioxidant system, synthesis of secondary metabolites, and accumulation of endogenous phytohormones. Furthermore, the review discusses recent findings from molecular genetic studies, specifically those concerning the genome, transcriptome, proteome, and metabolome. Emphasis is placed on the scientific and economic significance of understanding the fundamental processes underlying drought resistance, as it contributes to the selection and development of phenotypes capable of withstanding drought conditions.