氮限制与UV辐射对假微型海链藻光合特性的耦合效应  

Coupling effects of nitrogen limitation and ultraviolet radiation on photosynthetic performance of Thalassiosira pseudonana

作　　者：刘京华 王奕斐 臧纱纱 严芳 徐智广 王磊 吴红艳 LIU Jing-hua;WANG Yi-fei;ZANG Sha-sha;YAN Fang;XU Zhi-guang;WANG Lei;WU Hong-yan(School of life sciences,Ludong University,Key Laboratory of Marine Biotechnology in Universities of Shandong(Ludong University),Yantai 264025,China)

机构地区：[1]鲁东大学生命科学学院,山东省高校海洋生物技术重点实验室,山东烟台264025

出　　处：《生态学杂志》2022年第10期1984-1990,共7页Chinese Journal of Ecology

基　　金：山东省自然科学基金面上项目(ZR2019MC015和ZR2020MD092);山东省自然科学基金青年基金(ZR2020QC025)资助。

摘　　要：分析了不同氮水平下硅藻假微型海链藻(Thalassiosira pseudonana(Hustedt)Hasle et Heimdal CCMP 1335)对UV辐射的光合响应。结果表明:UV辐射显著抑制假微型海链藻PSII的最大光化学效率(F/F),且氮限制加剧该抑制效应;氮限制条件下藻细胞反应中心净关闭速率(M)升高,Q_(A)^(-)向Q的电子传递效率(ψ)下降,对光能的吸收效率(α)下降,从而使得藻细胞对UV辐射的耐受能力降低;UV辐射下,尤其是氮限制时,藻细胞PSII的修复速率与损伤速率(r/k)的比值显著降低,表明UV辐射通过对修复过程的抑制,使得两者耦合对假微型海链藻的光合抑制效应加剧;氮限制与UV辐射的耦合作用显著降低假微型海链藻的光合能力,从而影响其初级生产。In this study,we examined the photosynthetic response of diatom Thalassiosira pseudonana to UV radiation under different nitrogen concentrations.Results showed that the maximum photochemical yield(F/F)of PSII was significantly inhibited by UV radiation,which was aggravated by nitrogen limitation.Under nitrogen limitation,the net closing rate of the reaction center(M)increased,the electron transfer efficiency fromQ_(A)^(-)to Q(ψ)decreased,the absorption efficiency of light energy(α)was depressed,which together reduced the tolerance of T.pseudonana cells to UV radiation.UV radiation,especially when under nitrogen limitation,significantly decreased the ratio of PSII repair rate to damage rate(r/k),indicating that the photoinhibition of PSII was intensified by UV radiation through the damage of repair process.Our results suggest that the combination of nitrogen limitation and UV radiation could decrease photosynthetic capacity of T.pseudonana,with consequences on the primary production.

关 键 词：硅藻 光抑制 氮限制 UV辐射 

分 类 号：Q945[生物学—植物学]