Effects of environmental stress on nitric oxide emission from Hordeum vulgare seedlings

By using cherailuminescence technique, this paper studied the nitric oxide (NO) emission from Hordeum vulgare seedlings under high temperature, drought, salt, and heavy metals (cadmium and copper) stresses. Short-term high temperature stress induced the increase of H. vulgare seedlings NO emission, while long-term high temperature stress dropped the NO emission to the level of the control. Under short-term drought stress, the NO emission from the seedlings treated with high concentration polyethyleneglycol 6000 ( 25% and 30% ) increased significantly, but under long-term drought, the NO emission decreased. Similarly, the NO emission increased under short-term salt stress, but differed under long-term salt stress, depending on salt concentration, t. e., kept a lower level similar to the control at low salt concentration ( ≤400 mmol · L-1) but maintained at a higher level at high salt concentration (≥ 600 mmol · L-1 ). No significant change was observed in the NO emission under short-term heavy metals ( cadmium and copper) stress, but the emission increased significantly under long-term cadmium stress and low concentration copper stress. The results suggested that environmental stress induced the NO emission from H. vulgare seedlings, and the emission rate was correlated with the stress strength and stress duration.

Duke Scholars

Author Zhen-Ming Pei Biology