花色素苷在丁香新生叶光合机构中的作用

摘要

以叶片富含花色素苷的紫丁香Syringa oblata和花色素苷含量低的紫丁香变种白丁香Syringaoblata var.alba为试验材料,研究了丁香新生叶、半展开叶和展开叶中花色素苷对叶片光合机构的影响.结果表明:紫丁香新生叶片叶绿素含量较低,而花色素苷含量较高,其含量是白丁香叶片的17.3倍,单位反应中心吸收的光能(ABS/RC)低于白丁香20.17％,并且吸收的光能用于电子传递的比例((Φ)Eo)和单位反应中心用于电子传递比例(ETo/RC)也显著低于白丁香,紫丁香新生叶片的光化学效率和电子传递速率明显低于白丁香.紫丁香新生叶片中的花色素苷减少了PS Ⅱ对光能的吸收,降低了PS Ⅱ反应中心的光能转换效率和原初反应速度,因此,紫丁香新生叶片激发能产生的数量明显低子白丁香.白丁香新生叶片中叶绿素含量较高,叶片中花色素苷含量较低,比紫丁香叶片吸收光能的能力强,其新生叶片中有活性的反应中心的数量和反应中心的活性较高,对光能的利用能力明显高于紫丁香;白丁香新生叶片的非光化学淬灭(NPQ)、非光化学猝灭的最大量子产额((Φ)Do)和单位反应中心耗散掉的能量(DIo/RC)明显高于紫丁香.因此可以推断花色素苷改变了紫丁香和白丁香新生叶对光能吸收和利用的途径和过剩光能耗散的方式.%By taking Syringa oblata leaves (be rich in anthocyanin) and Syringa oblata var. alba leaves (with lower content of anthocyanin) as the tested materials, the effects of anthocyanin in new, semi-expansion and expanded leaves on photosynthetic apparatus have been investigated. The results show that the young leaves of S. oblata had a lower chlorophyll content, while had a higher anthocyanin content, S. oblata' s anthocyanin content was 17.3 times of S. oblata var. alba' s; S. oblata' s absorption flux per reaction center (ABS/RC) was lower than S. oblata var. alba' s by 20.17%; the proportion of absorbed light energy that was used to transfer electron and the proportion of ET0/RC were significantly lower than that of the latter; S. oblata' s photochemical efficiency and electron transport rate were obviously lower the latter, respectively. S. oblata' s Anthocyanin decreased PS Ⅱ' s absorption of light energy, and inhibited the conversion efficiency of PS Ⅱ' s light energy and the rate of primal process of photosynthesis, therefore, the excitation energy produced by S. oblata new leaves was lower that that of 5. oblata var. alba' s. Syringa oblata var. alba had a higher chlorophyll content, a lower anthocyanin content, so had a stronger ability in light energy absorption than S. oblate; S. oblata var. alba' s new leaves had more reaction centers with activity and the reaction centers had high activity, so its utilization ability of light energy was higher than S. oblata; S. oblata var. alba' s non-photochemical quenching (NPQ), NPQ' s maximal quantum yields and the energy that was dissipated by unit reaction center were obviously higher than that of S. oblata' s. Hence, it can be concluded that the anthocyanin changed the absorption and utilization way of light energy as well as the excitation energy dissipation in Syringa oblata and Syringa oblata var. alba young leaves.