Effects of Exogenous Nitric Oxide on Wheat Exposed to Enhanced Ultraviolet-B Radiation

We explored the use of exogenous nitric oxide (NO) on alleviating effects of UV-B light on winter wheat development. Triticum aestivum L. cv. Linyou 7287 seeds were irradiated with UV-B (10.08 kJ·m·d) (enhanced UV-B) and watered with either water or 100 μmol·L SNP solution. Plants were also watered with the SNP alone. The results showed that enhanced UV-B produced negative effects on seedling development. Leaf length decreased and seedling biomass dropped significantly compared with the control. Photochemical efficiency (Fv/Fm) dropped, and chlorophyll and carotenoid content as well as the ATPase activity declined. Content of UV-absorbing compounds and activity of the POD increased compared to the control. Application of the SNP, a NO donor partially protected wheat seedlings exposed to elevated UV-B radiation in that their leaf lengths and biomass accumulation were enhanced compared to the UV-B treatment alone. SNP also improved the contents of chlorophyll, carotenoid and UV-absorbing compounds in leaves. ATPase activity was enhanced but no influence on POD activity. Furthermore, the application of SNP alone showed a favorable effect on seedling growth compared with the control.