Plant aquaporins alleviate drought tolerance in plants by modulating cellular biochemistry, root‐architecture, and photosynthesis

Abstract

Water is a vital resource for plants to grow, thrive, and complete their life cycle. In recent years, drastic changes in the climate, especially drought frequency and severity, have increased, which reduces agricultural productivity worldwide. Aquaporins are membrane channels belonging to the major intrinsic protein superfamily, which play an essential role in cellular water and osmotic homeostasis of plants under both control and water deficit conditions. A genome-wide search reveals the vast availability of aquaporin isoforms, phylogenetic relationships, different families, conserved residues, chromosomal locations, and gene structure of aquaporins. Furthermore, aquaporins gating and subcellular trafficking are commonly controlled by phosphorylation, cytosolic pH, divalent cations, reactive oxygen species, and stoichiometry. Researchers have identified their involvement in regulating hydraulic conductance, root system architecture, modulation of abiotic stress-related genes, seed viability and germination, phloem loading, xylem water exit, photosynthetic parameters, and post-drought recovery. Remarkable effects following the change in aquaporin activity and/or gene expression have been observed on root water transport properties, nutrient acquisition, physiology, transpiration, stomatal aperture, gas exchange, and water use efficiency. The present review highlights the role of different aquaporin homologs under water-deficit stress condition in model and crop plants. Moreover, the opportunity and challenges encountered to explore aquaporins for engineering drought-tolerant crop plants are also discussed here. | INTRODUCTIONWater scarcity caused by prolonged dry condition in a natural climatic cycle and lack of precipitation is termed as drought. Nowadays, climate change and rising mean atmospheric temperature have increased drought frequency causing serious damage to agriculture, health, environment, energy, and economy. According to the United Nations and World Bank 2018 report, 40% of the world population is affected by water scarcity with a serious impact on their crops and livestock. Water scarcity may cost up to 6% of the total gross domestic product of some regions by 2050, which will be a huge liability for developing and underdeveloped countries (UNCCD, 2020).Water deficit severely affects plants' growth, physiology, reproduction, and yield by altering molecular, biochemical, and physiological processes. Plants have developed various mechanisms like increased water uptake, increased root/shoot ratio, stomatal closure, accumulation of osmolytes, and scavenging reactive oxygen species (ROS) to combat water deficit conditions (Jha et al., 2019). Developing engineered crops with enhanced drought tolerance ability through traditional breeding or modern transgenic approaches is a necessity to fulfill the demand for global food security. Recently, genome editing

Differential Physio-Biochemical and Metabolic Responses of Peanut (Arachis hypogaea L.) under Multiple Abiotic Stress Conditions

“…Plants under combined abiotic stresses also differ from those that are under individual stresses for photosynthesis, stomatal regulation, and water use efficiency (WUE) [ 7 , 8 ]. For example, the net photosynthesis rate of soybean decreased more under combined water deficit and heat stress than individual stresses due to reduced CO 2 availability, lower relative water content (RWC), and higher leaf temperature [ 9 , 10 ]. Similarly, WUE (directly linked to stomatal opening or closing) decreased in most studies under different stress combinations [ 11 , 12 ].…”

Trehalose increases tomato drought tolerance, induces defenses, and increases resistance to bacterial wilt disease

“…Accordingly, Arabidopsis PIP family aquaporin proteins were generally downregulated during drought stress (Alexandersson, Fraysse et al 2005). Tomato aquaporins are encoded by diverse families and channel other solutes in addition to water, so it would not be expected that all aquaporins play the same role during bacterial wilt (Reuscher, Akiyama et al 2013, Patel and Mishra 2021).…”

Molecular and Physiological Perspectives of Abscisic Acid Mediated Drought Adjustment Strategies

“…Accumulation of ABA also regulates the architecture of the root system and hydraulic conductivity unit length root conductance [143,144]. Predominantly, root water uptake in plants is influenced by ABA inducible water channel proteins named aquaporins that alter cell water permeability to maintain cellular water and osmotic homeostasis [145,146].…”