SGER: The Response of Marine Phytoplankton to Climate Change: Characterization of Rubisco Activase

无机碳在调节海洋生产力和浮游植物群落的物种组成中起着至关重要的作用。因此，了解不同浮游植物组合对无机碳的固定机制，对于理解浮游植物光合作用对全球气候变化的响应，以及建立真实的海洋化学碳通量模型至关重要。Rubisco是驱动卡尔文循环功能的关键酶。然而，它现在是有据可查的，陆生植物Rubisco是催化非？在没有CO的情况下运行？Rubisco活化酶的相互作用。到目前为止，在文献中还没有关于Rubisco活化酶对绿色植物色素的功能的信息。事实上，除了赤潮异弯藻和两种刺囊藻外，没有任何关于这一组合中任何其他代表的Rubisco催化功能的数据，这在全球碳加工中是如此关键。特别是，B）将Rubisco活化酶的研究扩展到包括硅藻，因为它们是CO2管理的主要贡献者。在大肠杆菌中表达大肠杆菌; B）已经完成了对异弯藻Rubisco的广泛分析; c）已经记录了响应于光线索的Rubisco mRNA产生的模式; d）异弯藻和硅藻Rubisco抗体已经显示出交叉反应; e）抗体的流式细胞术测量？虽然研究浮游植物中Rubisco活化酶对Rubisco的调节可能存在风险，但本研究将建立一个初步的有色藻类数据库，其中通过Rubisco/Rubisco活化酶相互作用的无机碳处理的生物化学被破译。长的？长期效益当考虑到预测光合作用对气候变化的反应时，这项研究是非常重要的。

Inorganic carbon plays a crucial role in regulating marine productivity and species composition in phytoplankton communities. Therefore understanding the mechanisms underlying inorganic carbon fixation by different phytoplankton assemblages is critical if we are to understand the response of phytoplankt on photosynthesis to global climate change, and to develop realistic models of biogeochernical carbon flux in the ocean.Rubisco is a keystone enzyme that drives Calvin cycle function. However, it is now well documented that terrestrial plant Rubisco is catalytically non?functional without the co?operative interplay of Rubisco activase. To date, no information exists in the literature concerning the function of Rubisco activase for gLny chromophytic alga. In fact, except for Heterosigma akashiwo and two Cylindrotheca species, no data exists on Rubisco catalytic function for any other representative of this assemblage that is so critical in global carbon processing.The Goals of this project are to: a) Isolate and characterize Rubisco activase using Heterosigma as model chromophytic algal species; and, in particular, to b) Extend Rubisco activase studies to include diatoms since they rank as primary contributors in C02 management.The study is feasible because: a) The cloned, putative Heterosigma activase gene has now been over?expressed in E. coli; b) Extensive analysis of Heterosigma Rubisco has been accomplished; c) Patterns of Rubisco mRNA production in response to light cues have been documented; d) Heterosigma and diatom Rubisco antibodies have been shown to cross react; e) Flow cytometric measurements of antibody?tagged Rubisco have been made.While the effort in understanding the regulation of Rubisco by Rubisco activase in phytoplankton may be risky, this study will establish a primary database for chromophytic algae wherein the biochemistry of inorganic carbon processing via Rubisco/Rubisco activase interaction is deciphered. The long?term benefit this study is highly significant when considered in terms of predicting photosynthetic performance in response to climate change.