Nitric oxide reduces Cu toxicity and Cu-induced NH4+ accumulation in rice leaves.
Nitric oxide (NO) is a highly reactive, membrane-permeable free radical, which has recently emerged as an important antioxidant. Here we investigated the protective effect of NO against the toxicity and NH4+ accumulation in rice leaves caused by excess CuSO4 (10mmol L(-1)). It was found that free radical scavengers (sodium benzoate, thiourea, and reduced glutathione) reduced the toxicity and NH4+ accumulation in rice leaves caused by excess CuSO4. NO donor sodium nitroprusside (SNP) was also effective in reducing CuSO4-induced toxicity and NH4+ accumulation in rice leaves. The protective effect of SNP on the toxicity and NH4+ accumulation can be reversed by 2-(4-carboxy-2-phenyl)-4,4,5,5-tetramethyl- imidazoline-1-oxyl-3-oxide, a NO scavenger, suggesting that the protective effect of SNP is attributable to NO released. Results obtained in the present study suggest that reduction of CuSO4-induced toxicity and NH4+ accumulation by SNP is most likely mediated through its ability to scavenge active oxygen species.
Yu
Chia Chi
CC
Department of Agronomy, National Taiwan University, Taipei, Taiwan, China.
Hung
Kuo Tung
KT
Kao
Ching Huei
CH
D000975:Antioxidants / Q000378:metabolism; D003300:Copper / Q000633:toxicity*; D019327:Copper Sulfate / Q000633:toxicity*; D016166:Free Radical Scavengers / Q000494:pharmacology; D009569:Nitric Oxide / Q000502:physiology*; D009599:Nitroprusside / Q000494:pharmacology; D012275:Oryza / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D018515:Plant Leaves / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D010940:Plant Proteins / Q000378:metabolism; D000644:Quaternary Ammonium Compounds / Q000378:metabolism*
D000975:Antioxidants; D016166:Free Radical Scavengers; D010940:Plant Proteins; D000644:Quaternary Ammonium Compounds; D009599:Nitroprusside; D009569:Nitric Oxide; D003300:Copper; D019327:Copper Sulfate