Effect of Nitric Oxide on Alleviating Cadmium Toxicity in Rice （Oryza sativa L.）

• Published in: 农业科学学报：英文版 no. 9; pp. 1540 - 1550
• Main Author: ZHAO Xiu-feng CHEN Lin Muhammad I A Rehmani WANG Qiang-sheng WANG Shao-hua HOU Peng-fu LI Gang-hua DING Yan-feng
• Format: Journal Article
• Language: English
• Published: 2013
• Subjects: 一氧化氮; 亚铁氰化钾; 单核苷酸多态性; 抗氧化酶活性; 水稻植株; 镉毒害; 镉（Cd）; 非生物胁迫
• ISSN: 2095-3119; 2352-3425

Nitric oxide （NO） is a gaseous signaling molecule in plants that plays a key role in mediating a wide range of physiological processes and responses to biotic and abiotic stresses. The present study was conducted to investigate the effects of the exogenous application of sodium nitroprusside （SNP）, an NO donor, on cadmium （Cd）-induced oxidative stress and Cd uptake in rice plants. Rice plants were exposed to Cd stress （0.2 mmol L^-1 CdC12） and different concentrations of SNP （0.05, 0.1, 0.2, and 0.4 mmol L^-1）. A SNP concentration of 0.1 mmol L^-1 （SNP 10） significantly reduced the Cd-induced decrease in shoot and root dry weights and leaf chlorophyll concentrations. The addition of NO also reduced the malondialdehyde （MDA）, hydrogen peroxide （H202） and ascorbic acid （ASA） concentrations. However, the reduction in glutathione （GSH） concentration was inhibited by NO treatment. Moreover, NO prevented the Cd-induced increase in antioxidative enzyme activity. The amount of Cd accumulation in rice plants was also influenced by the addition of NO. The NO supplied by the SNP enhanced the Cd tolerance of the rice by increasing the Cd uptake by the roots and decreasing the Cd accumulation by the shoots. However, the application of potassium ferrocyanide （Cd＋Fe） or sodium nitrate and nitrite （Cd＋N） （without NO release）, did not exhibit the effects of the SNP. Furthermore, the effects of the SNP were reversed by the addition of hemoglobin （an NO scavenger）. Our results suggested that exogenous NO was involved in the resistance of rice to Cd-toxicity.