New Insight into Plant Saline-Alkali Tolerance Mechanisms and Application to Breeding

Abstract

Saline-alkali stress is a widespread adversity that severely affects plant growth and productivity. Saline-alkaline soils are characterized by high salt content and high pH values, which simultaneously cause combined damage from osmotic stress, ionic toxicity, high pH and HCO3−/CO32− stress. In recent years, many determinants of salt tolerance have been identified and their regulatory mechanisms are fairly well understood. However, the mechanism by which plants respond to comprehensive saline-alkali stress remains largely unknown. This review summarizes recent advances in the physiological, biochemical and molecular mechanisms of plants tolerance to salinity or salt- alkali stress. Focused on the progress made in elucidating the regulation mechanisms adopted by plants in response to saline-alkali stress and present some new views on the understanding of plants in the face of comprehensive stress. Plants generally promote saline-alkali tolerance by maintaining pH and Na+ homeostasis, while the plants responding to HCO3−/CO32− stress are not exactly the same as high pH stress. We proposed that pH-tolerant or sensitive plants have evolved distinct mechanisms to adapt to saline-alkaline stress. Finally, we highlight the areas that require further research to reveal the new components of saline-alkali tolerance in plants and present the current and potential application of key determinants in breed improvement and molecular breeding.

Redox regulation by the CDSP32 thioredoxin of ATP-synthase activity and enzymatic antioxidant network inSolanum tuberosum

“…4). Plant adaptation to saline-alkaline stress has been only recently investigated (Cao et al 2022; Rao et al 2023), and involves common responses with neutral salt stress like hormone signalling, accumulation of osmolytes and regulation of ion homeostasis, but also more specific responses to limit pH modification within plant cells (Cao et al 2022). Saline-alkaline conditions strongly impair ROS production levels and cell redox homeostasis (Rao et al 2023).…”

Physiological studies and transcriptomic analysis reveal the mechanism of saline–alkali stress resistance of Malus sieversii f. niedzwetzkyan

“…Saline-alkali stress is a complex stress that can disrupt the structure of plant cells, accelerate the generation of ROS, induce damage to plants, and disrupt metabolic pathways (Cao et al, 2022;Forni et al, 2017). Transcriptional regulation, morphophysiological responses, and biochemical metabolic processes play key roles in the responses of plants to environmental stimuli (Yu et al, 2020).…”

Carboxylic acid accumulation and secretion contribute to the alkali-stress tolerance of halophyte Leymus chinensis

“…Understanding the mechanisms of alkali-tolerant halophytes will be useful for addressing the existing issue in alkalized grasslands. Alkali stress affects plants through osmotic regulation, ion toxicity and high pH, as well as resulting in indirect oxidative stress ( Wang et al., 2012 ; Rao et al., 2013 ; Cao et al., 2022 ). High pH levels caused by alkali stress can significantly disrupt the pH stability of plant cells and compromise the integrity of cell membranes ( Fang et al., 2021 ).…”

“…Recently, increased attention has been given to alkali stress tolerance of plants ( Cao et al., 2022 ), especially that of glycophytes, such as Arabidopsis ( Yang et al., 2019 ), maize ( Cao et al., 2020 ), rice, sorghum and millet ( Zhang et al., 2023 ). In Arabidopsis and maize, H + -ATPases play important roles in alkali tolerance ( Yang et al., 2019 ).…”