Gamma-Aminobutyric Acid and Salicylic Acid Regulated Osmolyte Accumulation, Nutrient Acquisition, and ROS Metabolism to Decrease Arsenic Effects on Sunflower (Helianthus annuus L.) at Vegetative Stage

Gamma-aminobutyric acid Salicylic acid Arsenic Oxidative stress Antioxidant system Sunflower
["Nawaz, Muhammad","Hussain, Iqbal","Rasheed, Rizwan","Ashraf, Muhammad Arslan","Mahmood-ur-Rahman"] 2025-02-14 期刊论文
Arsenic (As) is a toxic metal that can harm plants by causing oxidative stress, stunting growth, and disrupting metabolism. This study investigates the potential effect of gamma-aminobutyric acid (GABA) and salicylic acid (SA) in mitigating the toxic effects of As on sunflower plants. The aim is to enhance growth, improve metabolite accumulation, strengthen antioxidant defenses, reduce oxidative stress, enhance nutrient status, and minimize As uptake in sunflower plants. To investigate the effect of GABA and SA on arsenic toxicity, two sunflower genotypes (FH-779 and FH-773) were exposed to arsenic at a concentration of 60 mg kg(-)(1) in the soil. The experimental design followed a completely randomized design with three replications of each treatment arranged in a factorial manner. The sunflower plants were treated with foliar sprays of GABA (200 mg L--(1)), SA (100 mg L--(1)), and a combination of both GABA + SA (200 + 100 mg L--(1)). Both FH-779 and FH-773 genotypes exhibited significant accumulation of As + 5 and As+ 3 in roots and leaves, resulting in reduced nutrient uptake. GABA, SA, and GABA + SA treatments alleviated As-induced oxidative stress by reducing hydrogen peroxide (H2O2) production and malondialdehyde (MDA) levels in both genotypes. These treatments also enhanced osmolyte accumulation, improving osmotic adjustment under As stress. Additionally, GABA and SA spray enhanced the activity of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD), aiding in scavenging reactive oxygen species (ROS) and preventing oxidative damage. The combination of GABA and SA had a more pronounced effect on the translocation and remediation of As compared to GABA and SA alone. Arsenic removal efficiency reached maximum in the GABA + SA treatment in both FH-779 and FH-773 genotypes, greater than control group, respectively. The findings of this study highlight the beneficial roles of gamma-aminobutyric acid and salicylic acid in mitigating the negative effects of arsenic on growth of sunflower plants. These compounds regulate photosynthetic pigments, osmotic pressure, and antioxidant defense systems, improve nutrient status, and reduce arsenic uptake. Salicylic acid and gamma-aminobutyric acid show potential for alleviating stress in other crops facing abiotic stress. This study highlights the impact of these compounds on plant defense mechanisms in stress conditions, providing a promising approach to reduce arsenic toxicity in crops, thereby improving agricultural productivity in contaminated environments.
来源平台:JOURNAL OF SOIL SCIENCE AND PLANT NUTRITION