Exogenous ABA Enhances the Antioxidant Defense System of Maize by Regulating the AsA-GSH Cycle under Drought Stress

Abstract

When drought occurs during the maize-filling period, the probability of yield decline increases. Abscisic acid (ABA) plays a regulatory role in physiological and metabolic activities during plant development. However, its effect on the antioxidant system of maize leaves during the grain-filling stage is unclear. Maize plants (Zhengdan958) were used as an experimental material, and ABA was sprayed on the leaves during the grain-filling stage. The plants were placed under drought conditions to analyze the relationship between the ascorbate-glutathione (AsA-GSH) cycle and hydrogen peroxide (H2O2) removal. Exogenous ABA significantly reduced the malondialdehyde content, relative electrolyte leakage, and H2O2 under drought stress. This is similar to the exogenous ABA effect on the AsA-GSH cycle. Exogenous ABA upregulated the transcription of related genes and alleviated the inhibition of drought stress on the monodehydroascorbate reductase and dehydroascorbate reductase activities, thereby further increasing the ascorbate peroxidase and glutathione reductase activities. It contributed to an increase in the AsA and GSH levels and inhibited the decrease in the AsA/dehydroascorbic acid and GSH/oxidized glutathione ratios. Therefore, exogenous ABA plays an important role in improving the antioxidant capacity and drought resistance physiology of maize by enhancing antioxidant enzyme activity and stabilizing the AsA and GSH redox state.

Biochar-Mediated Control of Metabolites and Other Physiological Responses in Water-Stressed Leptocohloa fusca

“…Gly I, and Gly II are two-step MG-detoxification pathways that convert MG to D-lactate using glutathione as a co-factor. Our results are broadly in line with previous findings [11,18,19,28,29,85,86], whereas, BC application considerably improved the antioxidants in L. fusca roots and shoots.…”

“…In wheat seedlings, it has been observed that the presence of AsA and GSH enhances osmoregulation, cellular water and nutrient status, photosynthetic rate, and overall plant growth and productivity [25,26]. Previous research showed that the AsA-GSH cycle helps plants regulate a number of physiological and molecular pathways in addition to scavenging ROS [25,[27][28][29].…”

Plants’ Physio-Biochemical and Phyto-Hormonal Responses to Alleviate the Adverse Effects of Drought Stress: A Comprehensive Review

“…Exogenous ABA spraying has been shown in some studies to improve plant stress tolerance in various crop species. However, research evaluating the responses of different Zea mays L. and Glycine max L. to drought stress using exogenous ABA and fluoridone is severely limited (ABA synthesis inhibitor) [236,237]. ABA substantially enhanced the activities of SOD and POD during drought stress, with a considerable drop after re-watering [235].…”

Benzylaminopurine and Abscisic Acid Mitigates Cadmium and Copper Toxicity by Boosting Plant Growth, Antioxidant Capacity, Reducing Metal Accumulation and Translocation in Bamboo [Pleioblastus pygmaeus (Miq.)] Plants

“…Hence, our results demonstrated that 6-BAP and ABA, both alone and in combination, significantly reduce H 2 O 2 , O 2 •− , TBARS, EL, SP, and LOX in the plants exposed to 100 µM Cd and 100 µM Cu. Numerous researchers have demonstrated the impact of 6-BAP and ABA on lipoperoxidation and ROS [ 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 ]. One of the strategies employed by plants under heavy metal stress is to increase their cellular soluble protein, which can help to decrease the intracellular osmotic potential and provide the plants with normal water status as well as preserving the physiology process in the cell.…”