Protective Effect of Nitric Oxide (NO) against Oxidative Damage in Larix gmelinii Seedlings under Ultraviolet-B Irradiation

Abstract

Ultraviolet-B (UV-B) stress appears to be more striking than other research works because of the thin ozone layer. The protective influence of an exogenous nitric oxide donor and sodium nitroprusside (SNP) on the growth properties of Larix gmelinii seedlings was investigated under ultraviolet-B radiation conditions. The results indicated that 0.1 mM SNP could effectively alleviate the damage caused by ultraviolet-B radiation, and improved the seedling growth properties, the relative water content, and photosynthetic pigment content in leaves. Additionally, the photosynthetic capacity and antioxidant enzyme activity were increased during the exposure. On the contrary, the damage caused by active oxygen was decreased in SNP-treated seedling leaves. The damage caused by ultraviolet-B radiation was slightly reduced after treating with 0.01 mM SNP. Nevertheless, treatment with 0.5 mM SNP had a negative effect under ultraviolet-B radiation. Furthermore, supplementing NO (nitric oxide) improved the photosynthetic capacity and antioxidant enzyme activity and alleviated the damage of caused by active oxygen. The best effective concentration of SNP was 0.1 mM. Therefore, a suitable amount of exogenous NO can protect the Larix gmelinii seedlings and increase their tolerance to ultraviolet-B radiation.

The light and dark sides of nitric oxide: multifaceted roles of nitric oxide in plant responses to light

“…Exogenous NO, applied as sodium nitroprusside (SNP), also promotes antioxidant defenses and ameliorates oxidative stress caused by excessive light (Xu et al, 2010) or UV-B exposure (Santa-Cruz et al, 2014;Hu et al, 2016). The ameliorative action of NO on chloroplast function under UV-B stress was confirmed by SNP-induced reduction of thylakoid membrane protein oxidation, prevention of chlorophyll loss and limited accumulation of H 2 O 2 , as well as the restorative effect on PSII activity in UV-B treated common bean leaves (Shi et al, 2005).…”