Effects of exogenous nitric oxide on active oxygen metabolism and photosynthetic characteristics of tomato seedlings under cadmium stress

• Published in: Ying yong sheng tai xue bao Vol. 21; no. 6; p. 1432
• Main Authors: Zhang, Yi-Kai, Cui, Xiu-Min, Yang, Shou-Xiang, Chen, Xiu-Ling
• Format: Journal Article
• Language: Chinese
• Published: China 01-06-2010
• Subjects: Cadmium - toxicity; Lycopersicon esculentum - drug effects; Lycopersicon esculentum - metabolism; Lycopersicon esculentum - physiology; Nitric Oxide - pharmacology; Photosynthesis - physiology; Reactive Oxygen Species - metabolism; Seedlings - metabolism; Seedlings - physiology; Stress, Physiological
• ISSN: 1001-9332

A hydroponic experiment was conducted to study the effects of exogenous sodium nitroprusside (SNP), a NO donor, on the active oxygen metabolism and photosynthetic characteristics of tomato (Lycopersicon esculentum Mill.) seedlings under Cd stress. The results showed that under the stress, applying 100 micromol x L(-1) SNP promoted the activities of plant superoxide dismutase (SOD) and catalase (CAT) significantly, increased the leaf- and root calcium (Ca) and iron (Fe) contents and the leaf chlorophyll content, net photosynthetic rate (P(n)), transpiration rate (T(r)), and stomatal conductance (G(s)), and decreased the contents of H2O2 and MDA and the concentration of intercellular CO2 (C(i)). The addition of hemoglobin, a NO scavenger, eliminated the effects of SNP, while applying 100 micromol x L(-1) sodium nitrate or nitrite (the decomposition products of NO or its donor SNP) or 100 micromol x L(-1) sodium ferrocyanide (an analog of SNP) had no significant alleviation effects on Cd stress. This study sugge