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

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.