外源NO对干旱胁迫下茶树生理特性的影响

Effect of Exogenous Nitric Oxide on Physiological Characteristics of Tea Plants under Drought Stress

摘要: 研究外源NO对干旱胁迫生理生化反应。以15% 聚乙二醇（PEG 6000）模拟干旱胁迫，0.5 mmol·L^-1的外源NO供体（SNP）处理对茶树幼苗叶片游离脯氨酸、丙二醛（MDA）的含量及保护酶活性的影响。结果表明，一定浓度的SNP缓解干旱胁迫伤害的效果较好，显著提高了受干旱胁迫茶树幼苗叶片的保护酶（CAT）活性和游离脯氨酸含量，并降低了MDA的含量。表明外源NO通过提高干旱胁迫下渗透调节物质含量和保护酶活性，降低MDA的含量，缓解干旱胁迫对茶树幼苗的损伤，增强植株的抗旱性。

Abstract: Physiological and biochemical responses of tea plants to drought stress by addition of nitric oxide (NO) in soil were studied. Under a simulated drought stress by adding 15% PEG 6000 to the soil, the effects of 0.5 mmol·L^-1 SNP on the activities of protective enzymes as well as the contents of free proline and MDA in the leaves of the tea seedlings were determined. The results showed that, with the NO addition, the activity of CAT and content of free proline in leaves increased significantly, while MDA decreased. It suggested that the exogenous NO enhanced the tolerance of the tea seedlings to drought via an increase in enzymatic activity, the osmotic adjustment by added substances, and a reduction on MDA.