Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Moscow Region 142290, Russia.
J Photochem Photobiol B. 2013 May 5;122:1-6. doi: 10.1016/j.jphotobiol.2013.02.016. Epub 2013 Mar 5.
Seedlings of 10-day-old lettuce (Lactuca sativa L., cultivar Berlin) were preilluminated by low intensity red light (λmax=660 nm, 10 min, 5 μmol quanta m(-2) s(-1)) and far-red light (λmax=730 nm, 10 min, 5 μmol quanta m(-2) s(-1)) to study the effect of pre-treatment on photosynthesis, photochemical activity of photosystem II (PSII), the contents of photosynthetic and UV-A-absorbing pigments (UAPs) and H2O2, as well as total and ascorbate peroxidase activities in cotyledonary leaves of seedlings exposed to UV-A. UV radiation reduced the photosynthetic rate (Pn), the activity of PSII, and the contents of Chl a and b, carotenoids and UAPs in the leaves, but increased the content of H2O2 and the total peroxidase activity. Preillumination with red light removed these effects of UV. In turn, the illumination with red light, then far-red light removed the effect of the red light. Illumination with red light alone increased the content of UAPs, as well as peroxidase activity. It is suggested that higher resistance of the lettuce photosynthetic apparatus to UV-A radiation is associated with involvement of the active form of phytochrome B, thereby increasing peroxidase activities as well as UAPs and saving preservation of photosynthetic pigment contents due to pre-illumination with red light.
将 10 天大的生菜（Lactuca sativa L.，品种柏林）幼苗预照以低强度的红光（λmax=660nm，10min，5μmol 量子 m(-2) s(-1)) 和远红光（λmax=730nm，10min，5μmol 量子 m(-2) s(-1))，以研究预处理对光合作用、光系统 II（PSII）的光化学活性、光合和 UV-A 吸收色素（UAPs）以及 H2O2 的含量以及暴露于 UV-A 的子叶叶片中总过氧化物酶和抗坏血酸过氧化物酶活性的影响。UV 辐射降低了光合速率（Pn）、PSII 活性以及叶片中 Chl a 和 b、类胡萝卜素和 UAPs 的含量，但增加了 H2O2 和总过氧化物酶活性的含量。红光预处理消除了这些 UV 影响。反过来，红光再远红光的光照消除了红光的影响。单独的红光照射增加了 UAPs 的含量以及过氧化物酶活性。这表明生菜光合器官对 UV-A 辐射的更高抗性与活性形式的光敏素 B 的参与有关，从而增加了过氧化物酶活性以及 UAPs，并由于红光预处理而保存了光合色素含量。
