PHYSIOLOGICAL LIMITATION OF PHYTOPLANKTON PHOTOSYNTHESIS IN THE EASTERN EQUATORIAL PACIFIC DETERMINED FROM VARIABILITY IN THE QUANTUM YIELD OF FLUORESCENCE
PHYSIOLOGICAL LIMITATION OF PHYTOPLANKTON PHOTOSYNTHESIS IN THE EASTERN EQUATORIAL PACIFIC DETERMINED FROM VARIABILITY IN THE QUANTUM YIELD OF FLUORESCENCE
复制标题
DOI：
10.4319/lo.1994.39.5.1061
复制
发表时间：
1994-07-01
影响因子：
4.5
通讯作者：
FALKOWSKI, PG
中科院分区：
文献类型：
--
作者：
GREENE, RM;KOLBER, ZS;FALKOWSKI, PG
在赤道东太平洋的一个样带研究中，从高营养、低叶绿素的热带沃茨到贫营养的亚热带沃茨，我们通过快速重复频率荧光计测定了叶绿素荧光量子产率（Δ phi（m））的最大变化的变异性。Δ phi（m）是光系统2中光化学能量转换效率的定量量度，其可变性由光合机构的功能组织决定。结果表明，DELTAphi（m）是相对较低的整个营养丰富的赤道沃茨，提供了明确的证据，在自然浮游植物种群的光化学能量转换效率的生理限制。船上富集研究表明，在加入纳摩尔浓度的无机铁以及以类似铁浓度加入的气溶胶粉尘后，DELTAphi（m）增加。这种反应反映了铁诱导修复的光系统2功能在封闭的瓶社区。赤道潜流顶部的低DELTAphi（m）表明，涌上表面的铁量不足以修复光系统2的功能。我们的研究结果强烈表明，铁的可用性限制了光化学能量转换效率，是控制营养丰富的赤道太平洋光合作用和生长速率的主要机制。
On a transect study in the eastern equatorial Pacific, from the high-nutrient, low-chlorophyll tropical waters to the oligotrophic subtropical waters, we determined the variability in the maximum change in the quantum yield of chlorophyll fluorescence (DELTAphi(m)) by means of a fast repetition rate fluorometer. DELTAphi(m) is a quantitative measure of photochemical energy conversion efficiency in photosystem 2, the variability of which is determined by the functional organization of the photosynthetic apparatus. The results revealed that DELTAphi(m) was relatively low throughout the nutrient-rich equatorial waters, providing unequivocal evidence for physiological limitation of photochemical energy conversion efficiency in the natural phytoplankton populations. Shipboard enrichment studies showed that DELTAphi(m) increased following addition of nanomolar concentrations of inorganic iron as well as aerosol dust added at similar iron concentrations. This response reflects an iron-induced repair of photosystem 2 function in the enclosed bottle community. Low DELTAphi(m) at the top of the Equatorial Undercurrent indicated that the amount of iron upwelled to the surface was insufficient to repair photosystem 2 function. Our results strongly suggest that iron availability limits photochemical energy conversion efficiency and is the principal mechanism controlling rates of photosynthesis and growth in the nutrient-rich equatorial Pacific.