Iron Limitation and Phytoplankton Photosynthesis: Research Fellowship in Marine Biotechnology

最近的证据表明，铁的可获得性可能会限制许多海洋区域的浮游植物生物量和初级生产力。铁是光合作用电子传递链的关键组成部分；当浮游植物生长受到铁限制时，光合作用的速度和效率预计会降低。在该奖学金研究中，将利用生物物理、生化和免疫学技术来检测在铁限制的恒化器培养中，海洋浮游植物的光合作用装置在受控条件下对缺铁的表型响应。将对来自两个分类类群的生物进行种间比较，硅藻和球囊藻类。用分光光度法测定PS I反应中心叶绿素(P700)、细胞色素b复合体和可溶性电子载体铁氧还蛋白和黄还蛋白的浓度。氧闪光产率将被用来确定活性PS II反应中心的浓度，闪光荧光技术将被用来确定总PS II反应中心中活性的比例。来自海藻或高等植物的多克隆抗体将用于测定羧化酶核酮糖二磷酸羧基酶、类囊体类ATP合成酶、PS II反应中心复合体的几个组分和捕光复合体蛋白的相对丰度。

Recent evidence has indicated that the availability of iron may limit phytoplankton biomass and primary production in many oceanographic regions. Iron is a key component of the photosynthetic electron transport chain; reductions in the rate and efficiency of photosynthesis are expected when phytoplankton growth is iron-limited. In the fellowship research, biophysical, biochemical and immunological techniques will be used to examine the phenotypic response of the photosynthetic apparatus of marine phytoplankton to iron deficiency under controlled conditions in iron-limited chemostat cultures. Interspecific comparisons will be made between organisms from two taxonomic groups, a diatom and a coccolothophorid. The concentrations of the PS I reaction center chlorophyll (P700), the cytochrome b complex and the soluble electron carriers ferredoxin and flavodoxin will be measured spectrophotometrically. Oxygen flash yields will be used to determine the concentration of active PS II reaction centers, and flash fluorescence techniques will be used to determine the fraction of total PS II reaction centers which are active. Polyclonal antibodies from marine algae or higher plants will be used to determine the relative abundances of the carboxylating enzyme ribulose biphosphate carboxylase, the thylakoid ATP synthetase, several components of the PS II reaction center complex and light harvesting complex proteins.