Modeling the irradiance dependency of the quantum efficiency of photosynthesis

Abstract

Measures of the quantum efficiency of photosynthesis (f PSII ) across an irradiance (E) gradient are an increasingly common physiological assay and alternative to traditional photosynthetic-irradiance (PE) assays. Routinely, the analysis and interpretation of these data are analogous to PE measurements. Relative electron transport rates (rETR = E ¥ f PSII ) are computed and fit to a PE curve to retrieve physiologically meaningful PE parameters. This widespread approach is statistically flawed as the response variable (rETR) is explicitly dependent on the predictor variable (E). Alternatively the E-dependency of f PSII can be modeled directly while retaining the desired PE parameters by normalizing a given PE model to E. This manuscript presents a robust analysis in support of this alternative procedure. First, we demonstrate that scaling f PSII to rETR unnecessarily amplifies the measurement error of f PSII and using a Monte-Carlo analysis on synthetic data induces significantly higher uncertainty in computed PE parameters relative to modeling the E-dependency of f PSII directly. Next a large dataset is simultaneously fitted to four PE models implemented in their original and E-normalized forms. Four statistical criteria used to evaluate the efficacy of nonlinear models demonstrate improved model fits and more precise PE parameters when data are modeled as E-dependent changes in f PSII . The analysis presented in this manuscript clearly demonstrates that modeling the E-dependency of f PSII directly should be the norm for interpreting active fluorescence measures.

Comparison on light-response models of actual photochemical efficiency in photosystem II

“…, 其中F′ m 为光下的最大荧光, F s 为光下稳态荧光。 实验结果表明: Φ PSII 是一个依赖 光强的函数, 它随光强的增加而下降 (Genty et al, 1989;Krall & Edward, 1992;Ritchie, 2008;Ritchie & Bunthawin, 2010;Silsbe & Kromkamp, 2012;冯汉青 等, 2014;安东升等, 2015;林琭等, 2015;Ware et al, 2015)。 同时, Φ PSII 也可以由几个经验模型直接拟 合 (Laws et al, 2002;Smyth et al, 2004;Ritchie, 2008;Ritchie & Bunthawin, 2010;Silsbe & Kromkamp, 2012), 但这些经验模型主要应用于藻类和浮 游植物 (Laws et al, 2002;Smyth et al, 2004;Silsbe & Kromkamp, 2012)和少数几种陆生植物 (Ritchie, 2008;Ritchie & Bunthawin, 2010), 其他陆生植物应 用较少。已有的研究结果表明: 由指数模型分别拟…”

“…和植物经过暗适应的PSII最大光能利用效率F v /F m (F v 为可变荧光, F m 为最大荧光产量)差异较大, 且所 估算的饱和光强与实际测量值差异较大 (Laws et al, 2002;Smyth et al, 2004;Silsbe & Kromkamp, 2012); 负指数模型拟合ETR-I和Φ PSII -I的响应数据得到的…”

The Arctic picoeukaryote <i>Micromonas</i> pusilla benefits synergistically from warming and ocean acidification

“…Following the suggestion by Silsbe and Kromkamp (2012), the light-use efficiency was 185 estimated by fitting the data to the model by (Webb et al, 1974): 186…”

Efeito de ondas internas na produção fitoplanctônica da Plataforma Continental Sudeste do Brasil

“…Algumas espécies de microalgas possuem uma composição pigmentar voltada para absorção de luz em outras regiões do espectro de luz, como verificado em cianobactérias com a luz verde (RAATEOJA et al, 2004SCHREIBER et al, 2012SILSBE & KROMKAMP, 2012 Os resultados desse trabalho corroboram com os observados em diversos trabalhos feitos na para a região (BRANDINI, 1990;AIDAR et al, 1993;GAETA & BRANDINI, 2006;BRANDINI, 2003;CASTRO et al, 2006) em relação a regenerada em profundidades enriquecidas por essa massa de água. Na camada de mistura (50% de luz), os autores observaram predomínio da produção regenerada (>90% da produção total).…”