Catalase, superoxide dismutase and ascorbate-glutathione cycle enzymes confer drought tolerance of Amaranthus tricolor

Abstract The study was performed to explore physiological, non-enzymatic and enzymatic detoxification pathways of reactive oxygen species (ROS) in tolerance of Amaranthus tricolor under drought stress. The tolerant genotype VA13 exhibited lower reduction in growth, photosynthetic pigments, relative water content (RWC) and negligible increment in electrolyte leakage (EL), lower increment in proline, guaiacol peroxidase (GPOX) activity compared to sensitive genotype VA15. This genotype also had higher catalase (CAT), superoxide dismutase (SOD), remarkable and dramatic increment in ascorbate-glutathione content, ascorbate-glutathione redox and ascorbate-glutathione cycle enzymes activity compared to sensitive genotype VA15. The negligible increment of ascorbate-glutathione content, ascorbate-glutathione redox and ascorbate-glutathione cycle enzymes activities and dramatic increment in malondialdehyde (MDA), hydrogen peroxide (H 2 O 2 ) and EL were observed…