UV-B和NO对胞壁蛋白的影响

通过对玉米幼苗叶片细胞壁中蛋白组分、质量分数和过氧化物酶活性的分析检测,证明UV-B光胁迫下,内、外源NO作为UV-B辐射光氧化胁迫的信使负责胁迫信号的转导,激活细胞壁过氧化物酶的活性,致使细胞壁共价键结合蛋白,积累,从而钝化许多功能蛋白质的活力.而没有UV-B光胁迫时,适量的内、外源NO是抑制细胞壁过氧化物酶活性的有效抗胁迫分子,保证细胞壁中足量离子结合和游离蛋白质量分数,维持细胞壁中活跃的代谢功能.因此,在细胞壁中,一氧化氮能够介导UV-B辐射对细胞壁中结构和功能蛋白质的影响,为转导增强UV-B光胁迫的信号分子.

The effect of UV-B and NO on the protein in cell wall

The protein components, contents and peroxidase activities were examined and analyzed in the cell wall of maize seedling leaves amd it was found that the endo- and exogenous NO functioned as a signaling molecule responsible for the signal transduction of photo-oxidative stress under UV-B irradiation. The results showed that peroxidase activity and covalently bonded protein content were increased by UV-B radiation, and then the vitality of functional protein in the cell wall was decreased. On the other hand, the moderated endo- and exogenous NO, without UV-B light, inhibited the peroxidase activity so as to accumulate enough ionically bonded and free protein for the active metabolism therein. Consequently, it is assumed that exo-and endogenous nitric oxide is responsible for the up-regulation of regular function of the cell wall without ultraviolet-B. Under ultraviolet-B radiation, however, it might function as a signaling molecule of ultraviolet-B to carry out stress-signaling transduction in the cell wall.