Ascorbate as a Key Player in Plant Abiotic Stress Response and Tolerance

摘要: During their lifespan, plants are frequently exposed to adverse environmental conditions such as high solar irradiance, drought, heat, chilling, salinity, metal excess, and nutrient deficiency. The effects of these factors on often interrelated usually result in a decreased capacity carbon fixation photosynthesis, disturbed redox homeostasis, growth arrest. Under severe conditions, increased excitation pressure the chloroplasts exceeds antioxidative plant cells leading oxidative damage cellular constituents. Although ascorbate (Asc) level varies depending external factors, developmental stage, diurnal rhythm, light, its status is related homeostasis cell. In chloroplasts, peroxisomes, cytosol, Asc has key role hydrogen peroxide (H2O2) scavenging via peroxidase efficiently recycled ascorbate-glutathione (Asc–GSH) cycle directly by monodehydroascorbate reductase activity. apoplast vacuoles, main reductant phenolic radicals generated under stress. Besides role, an important complex well-orchestrated response network stress, performing multiple tasks signalling, regulation enzymatic activities, modulation gene expression, biosynthesis phytohormones, regulation. content state tightly compartments. Therefore, it emphasize distribution, which great impact reactive oxygen species signalling. Numerous studies transgenic with altered endogenous levels were done aim influence improve tolerance various abiotic stressors. this chapter, we discuss current understanding involvement metabolism stress response. Moreover, improved resilience stressors enzymes involved recycling will be discussed.