Physiological responses and regulatory pathways of transcription factors in plants under drought, high-salt, and low temperature stresses

Drought, high-salinity and low-temperature, three major environmental stresses, are important adverse factors limiting plant growth and development. These environment stressful factors usually trigger the physiological changes and the differential expressions of the transcription factors, which are involved in the biological regulations in the plants under abiotic stresses. While the functional gene expression are closely associated with these transcription factors, and are essential for an enhanced tolerance ability of plants to the environmental stresses. In recent years, most studies were mainly focused on discovering functional genes and the regulatory mechanisms of the transcription factors in plants in response to the environmental stresses. Therefore, uncovering on the physiological responses and the regulatory mechanisms of the transcription factors in plants under these environmental stresses has an important scientific significance in establishing molecular acclimation pathways of plants. This paper systemically characterized the physiological-biochemical changes in plants under environmental stresses including drought, high salinity, and low temperature, and profiled the structural and functional characteristics of MYB, bZIP, AP2/EREBP, WRKY and NAC, which commonly were related to plant stress resistance. Meanwhile, we separately characterized the responsive models and molecular regulatory mechanism of these transcription factors in response to these three environmental stresses. Under these environmental stresses, the growth rate, leaf area, leaf number, transpiration rate, and photosynthesis of plants were usually reduced, and the accumulation of reactive oxygen in plants led to the enhancement of membrane lipid peroxidation, thus resulting in severe damages of the plant cells. When the plants were exposed to these adverse environmental stresses, the antioxidant enzymatic activity and the contents of osmolytes in plants were naturally increased to establish adaptive acclimation mechanisms, which were usually exhibited at the physiological and molecular levels. The enhancement magnitude of the plant adaptability to the abiotic stresses are mainly regulated through the pathways of the interactions between the transcription factors and the specific recognition elements in the promoters of the stress-resistant genes or in the target proteins. This review provides a complete insight into the physiological-biochemical responses and molecular regulatory mechanisms of the transcription factors in plants under drought, high salinity, and low temperature stresses.