PHOTOSYNTHETIC EFFICIENCY IN UNICELLULAR DESERT GREEN ALGAE

单细胞沙漠绿藻的光合效率

• 批准号: 7953860
• 负责人: ZOE CARDON
• 金额: $ 0.56万
• 依托单位: MARINE BIOLOGICAL LABORATORY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-12-01 至 2009-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7953860
• 关键词: Attenuated; Chlorophyll; Chloroplasts; Computer Retrieval of Information on Scientific Projects Database; Confocal Microscopy; Fluorescence; Funding; Grana; Grant; Green Algae; Institution; Life; Light; Microbe; Phylogenetic Analysis; Plants; Protein Structure Initiative; Relative (related person); Research; Research Personnel; Resources; Scanning; Source; Taxon; Testing; Thylakoids; Time; United States National Institutes of Health; Vascular Plant; Water; attenuation; improved; interest; photosystem; reaction rate; segregation; trait

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. We are exploring aspects of photosynthetic efficiency in unicellular desert green algae and their closest known aquatic relatives. Desert green algae have evolved multiple independent times from aquatic ancestors, providing a statistically robust phylogenetic framework in which to test for suites of traits that correlate with evolutionary transitions of these eukaryotic microbes from water to land. Specifically, we are interested in photosynthetic efficiency. Light attenuation by terrestrial canopies tends to enrich the far-red wavelengths, which are preferentially absorbed by PSI, in lower canopy layers. In higher plants, the spatial segregation of PSII and PSI in granal-appressed and non-appressed thylakoid regions, respectively, minimizes the excitation transfer from PSII antennae to PSI (termed spillover), as well as the preferential use of excitation energy by PSI driven simply by its rapid reaction rates. Overall photosynthetic efficiency is enhanced by the separation of photosystems. More homogeneous distributions of PSI and PSII, and less-developed grana, in chloroplasts of many common aquatic green algae may improve photosynthetic function in water, where far-red wavelengths are the first wavelengths lost with depth. Attenuated light in deeper water is enriched with light preferentially absorbed by PSII, and the mixing of PSII and PSI in algal thylakoids may enhance excitation spillover from PSII to PSI, improving overall photosynthetic efficiency under water. The implicit idea is that grana stacking may correlate with green plant life on land, and a lack of stacking may correlate with green plant life in water. Closely related desert and aquatic green algae provide the opportunity to test this idea. We are using spinning disk confocal microscopy to scan multiple desert and aquatic taxa for grana stacks; the stacks show as punctate chlorophyll fluorescence because PSII (the main source of chlorophyll fluorescence we are detecting) is concentrated in grana stacks.

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 我们正在探索单细胞沙漠绿色藻类及其已知的最接近的水生亲属的光合效率方面。 沙漠绿色藻类已经从水生祖先进化了多个独立的时间，提供了一个统计学上稳健的系统发育框架，以测试与这些真核微生物从水到陆地的进化过渡相关的一系列特征。 具体来说，我们感兴趣的是光合效率。 光衰减的陆地冠层往往丰富的远红外波长，这是优先吸收PSI，在较低的冠层。在高等植物中，PSII和PSI的空间隔离在granal贴伏和非贴伏类囊体区域，分别减少了从PSII天线到PSI的激发转移（称为溢出），以及优先使用的激发能量由PSI驱动简单地由其快速的反应速率。总的光合效率通过光系统的分离而提高。PSI和PSII的更均匀的分布，和欠发达的基粒，在许多常见的水生绿色藻类的叶绿体可能会提高光合功能在水中，远红波长是第一个波长失去深度。衰减光在更深的水是丰富的光优先吸收PSII，和PSII和PSI在藻类类囊体的混合可能会增强激发溢出从PSII到PSI，提高整体光合效率在水中。隐含的想法是，基粒堆积可能与陆地上的绿色植物生命相关，缺乏堆积可能与水中的绿色植物生命相关。与此密切相关的沙漠和水生绿色藻类提供了检验这一观点的机会。 我们正在使用旋转圆盘共聚焦显微镜扫描多个沙漠和水生类群的基粒堆栈;堆栈显示为点状叶绿素荧光，因为PSII（我们检测的叶绿素荧光的主要来源）集中在基粒堆栈。