Plant aquaporins: A frontward to make crop plants drought resistant

Abstract

Drought stress alters gene expression and causes cellular damage in crop plants. Drought inhibits photosynthesis by reducing the content and the activity of the photosynthetic carbon reduction cycle, ultimately decreasing the crop yield. The role of aquaporins (AQP) in improving the growth and adaptation of crop plants under drought stress is of importance. AQP form channels and control water transport in and out of the cells and are associated with drought tolerance mechanisms. The current review addresses: (1) the evolution of AQPs in plants, (2) the classification of plant AQPs, (3) the role of AQPs in drought alleviation in crop plants, and (4) the phytohormone crosstalk with AQPs in crops exposed to drought stress.

Drought Stress Responses: Coping Strategy and Resistance

“…It was reported that ABA increases the activity of aquaporins and improves root hydraulic conductivity [ 44 ]. The activity of aquaporins is also regulated by gibberellins (GAs), CKs, methyl jasmonate (MeJA), and AUXs at transcriptional and post-transcriptional levels ([ 45 ] and references therein). The anisohydric strategy is beneficial under mild to moderate drought conditions but may be a risk under severe and long-term stress, which may cause hydraulic failure and severe dehydration [ 20 ].…”

“…Thanks to the efficient antioxidative system, plants can keep ROS at non-toxic levels, and these molecules are thought to act as signals for activation of stress defense responses [ 45 , 54 ]. It was also evidenced that NADPH oxidase localized in apoplastic fluid is involved in ROS production for integrating signaling networks involved in stress response processes.…”

Melatonin in Plant Defense against Abiotic Stress

“…Drought is the major stress that alters physiological, biochemical, and molecular processes in plants [11,12,98,99]. The plants grown in arid and semi-arid regions will face more intense and longer periods of drought [100].…”

“…The plants grown in arid and semi-arid regions will face more intense and longer periods of drought [100]. The urgent need of the hour in these changing environmental conditions is to promote adaptive agricultural strategies because numerous levels of sensitivity to water stress are shown by different organs [12,101]. Cucumis sativus exposed to melatonin has a higher rate of germination of seeds and root growth when grown in PEG-stressed conditions [36] and reduced drought-promoted leaf senescence in Agrostis [68].…”

“…Often correlated with a decrease in the soil water level, any significant reduction in the cultivable capacity of the soil often occurs with a change in the land use pattern from that typical of a fertile to marginal one [7,8]. It affects growth and development of crop plants via a reduction in germination, a decrease in the photosynthetic activity and carbon assimilation to a large extent, decreased flowering, and pollen sterility, and as such, acts as a major limiting factor for crop yield [9][10][11][12]. Abiotic stresses affecting different stages of plant growth constitute about 70% of the losses in yield among major crop plants like rice, wheat, corn, etc.…”