Aquaporins and their role in plant-microbial systems.

Global losses of agricultural products from water scarcity could be greater than from all other causes combined. Water deficiency in plants can result from insufficient precipitation, elevated air temperatures, and other factors that reduce the water available in the soil. Most terrestrial plants are able to form symbiosis with arbuscular mycorrhizal fungi. Arbuscular mycorrhiza plays a key role in the mineral nutrition of many terrestrial plant species. Water transport in plants is regulated primarily by aquaporins, transmembrane proteins. Aquaporins help plants save water, which is an important component of the plant's adaptation strategy to water scarcity. Some studies suggest that arbuscular mycorrhizal fungi can decrease the expression of aquaporin genes in plants under drought conditions, which reduces water transport within host plant tissues and conserves available water. On the other hand, there is little scientific evidence of the interaction mechanisms between plants and arbuscular mycorrhizal fungi during aquaporin regulation. In addition, the information in different sources on the aquaporin functions in different plant species may be contradictory. Plant aquaporins are represented by several subfamilies; their number varies for different species. A more comprehensive study of these transporters can enhance our understanding of water transport in plants and assess how arbuscular mycorrhizal fungi can influence it. This review contains data on the history of studies of the structure, localization, phylogeny, and functions of aquaporins. Advancing the study of the symbiotic system functioning may contribute to the development of biofertilizers based on soil microorganisms for agricultural uses in the Russian Federation.