外源一氧化氮对鹅毛竹离体叶片衰老的影响

以花后鹅毛竹为试验材料,10～50 mg·L-1硝普钠(SNP)为NO供体,研究外源NO对鹅毛竹离体叶片衰老的影响.结果显示:SNP预处理可不同程度地缓解鹅毛竹离体叶片衰老过程中蛋白质和叶绿素含量的下降,以30mg·L-1SNP处理效果最佳;与对照相比,离体处理5天后,叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)活性分别下降26.2%,35.6%,PSⅡ最大荧光(Fm)、最大光化学效率(Fv/Fm)、潜在活性(Fv,Fo)分别降低42.1%,38.2%,77.0%,而暗适应下最小荧光(Fo)则升高89.5%;经30 mg·L-1 SNP预处理后,上述生理指标的变化均受到显著抑制.适当浓度的NO预处理能够有效延缓花后鹅毛竹离体叶片的衰老进程.

Influence of Exogenous Nitric Oxide on Senescence in Detached Leaves of Shibataea chinensis

We examined effects of exogenous nitric oxide derived from a donor of 10 ~ 50 mg·L~(-1) sodium nitroprusside (SNP) on detached leaves of Shibataea chinensis after anthesis.The results showed that: decreases of leaf chlorophyll and protein content were alleviated to different degree when the isolated leaf was pretreated with different concentrations of SNP solution, among which the 30 mg·L~(-1) SNP had the best effect. Compared to control, the detached leaf SOD and POD activity were respectively decreased by 26.2% and 35.6% , maximum fluorescence of dark adaptation ( F_m) , PS II maximal photochemical efficiency (F_v/F_m), and PS II potential activity (F_v/F_o) were respectively decreased by 42.1 % ,38.2% ,77.0% , but the minimum fluorescence of dark adaptation( F_o) was increased 89.5% after 5 d treatment. However, after the pretreatment with 30 mg·L~(-1) SNP, the changes of all the above physiological parameters were inhibited significantly. The results demonstrated that proper concentration of exogenous nitric oxide was able to slow down efficiently the senescence process of detached leaves of S. Chinensis after anthesis.