UV-A/B radiation rapidly activates photoprotective mechanisms in Chlamydomonas reinhardtii
UV-A/B radiation rapidly activates photoprotective mechanisms in Chlamydomonas reinhardtii
复制标题
UV-A/B 辐射快速激活莱茵衣藻的光保护机制
DOI：
10.1093/plphys/kiab004
复制
发表时间：
2021
期刊：
影响因子：
7.4
通讯作者：
Minagawa Jun
中科院分区：
文献类型：
--
作者：
Tokutsu Ryutaro;Fujimura-Kamada Konomi;Yamasaki Tomohito;Okajima Keisuke;Minagawa Jun
在光合生物的叶绿体中通过光合作用将光能转化为化学能对于光自养生长是必不可少的，并且过量光能的非光化学猝灭（NPQ）防止活性氧的产生并在强光下维持高效的光合作用。在单细胞的绿色藻类莱茵衣藻中，NPQ被激活作为光保护机制，通过波长特异性的光信号通路介导的光致蛋白（蓝光）和紫外线（UV）光受体，但光保护激活的生物学意义与不同的质量仍然知之甚少。在这里，我们证明了NPQ依赖的光保护被紫外线激活的速度比可见光快。我们发现，诱导的基因表达和蛋白质积累相关的光保护是显着更快，更大的幅度在紫外线处理下相比，在蓝光或红光处理。紫外诱导的光保护因子的作用光谱表明，C.莱因哈德氏植物（Reinhardtisenses）感测相对长波长的UV（包括UV-A/B），而模式双子叶植物拟南芥（Arabidopsis thaliana）优先感测相对短波长的UV（主要是UV-B/C）以诱导光保护反应。因此，我们假设C. reinhardtii开发了一种与陆地植物不同的紫外线响应。
Conversion of light energy into chemical energy through photosynthesis in the chloroplasts of photosynthetic organisms is essential for photoautotrophic growth, and non-photochemical quenching (NPQ) of excess light energy prevents the generation of reactive oxygen species and maintains efficient photosynthesis under high light. In the unicellular green algaChlamydomonas reinhardtii, NPQ is activated as a photoprotective mechanism through wavelength-specific light signaling pathways mediated by the phototropin (blue light) and ultra-violet (UV) light photoreceptors, but the biological significance of photoprotection activation by light with different qualities remains poorly understood. Here, we demonstrate that NPQ-dependent photoprotection is activated more rapidly by UV than by visible light. We found that induction of gene expression and protein accumulation related to photoprotection was significantly faster and greater in magnitude under UV treatment compared with that under blue- or red-light treatment. Furthermore, the action spectrum of UV-dependent induction of photoprotective factors implied thatC. reinhardtiisenses relatively long-wavelength UV (including UV-A/B), whereas the model dicot plant Arabidopsis (Arabidopsis thaliana) preferentially senses relatively short-wavelength UV (mainly UV-B/C) for induction of photoprotective responses. Therefore, we hypothesize thatC. reinhardtiideveloped a UV response distinct from that of land plants.