Nitric Oxide- and Sulfur-Mediated Reversal of Cadmium-Inhibited Photosynthetic Performance Involves Hydrogen Sulfide and Regulation of Nitrogen, Sulfur, and Antioxidant Metabolism in Mustard

This study aimed to test the role of hydrogen sulfide (H2S) in responses regarding nitric oxide- (NO) and sulfur (S)-mediated improvement photosynthesis growth under cadmium (Cd) stress mustard (Brassica juncea L. cv. Giriraj), integrate mechanisms S, nitrogen (N), antioxidant metabolism. The plants grown with Cd (200 mg kg−1 soil) exhibited reduced assimilation S N diminished photosynthetic performance, which was associated higher accumulation-induced excess reactive oxygen species (ROS) production. application 100 μM sodium nitroprusside (SNP, a NO donor) together more prominent concentration resulted increased S- N-use efficiency, production non-protein thiols phytochelatins, efficiency enzymatic (superoxide dismutase, ascorbate peroxidase, glutathione reductase), non-enzymatic antioxidants (ascorbate glutathione) limiting accumulation and, thus, oxidative radical, peroxide, thiobarbituric acid content). benefit manifested through modulation H2S use hypotaurine (HT; scavenger) or cPTIO (2-4-carboxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) treated plus reversed action reduction HT, suggesting that plays significant NO- S-mediated alleviation stress. interplay ES may be used augmenting Cd-grown plants.