近日，Plant and Cell Physiology期刊上發(fā)表了由John R. Evans（澳大利亞國立大學(xué)著名學(xué)者），Patrick B. Morgan（LI-COR科學(xué)家），Susanne von Caemmerer（澳大利亞國立大學(xué)著名學(xué)者）聯(lián)合撰文，題為“Light Quality Affects Chloroplast Electron Transport Rates Estimated from Chl Fluorescence Measurements”的研究論文。本論文在葉綠素?zé)晒鈪?shù)準(zhǔn)確獲取方面又取得了重要進(jìn)展。

通過葉綠素?zé)晒鉁y量，可計算電子傳遞速率ETR。LI-6800便攜式光合作用測量系統(tǒng)可同步采集氣體交換和葉綠素?zé)晒鈪?shù)。研究者們通過實測葉綠素?zé)晒鈪?shù)，計算了電子傳遞速率ETR，并且，在抑制光呼吸的條件下測量了葉片的氣體交換參數(shù)。結(jié)果發(fā)現(xiàn)，如果作用光是藍(lán)光，會高估電子傳遞速率ETR近兩倍，而選用紅光則不存在這種情況。本項研究結(jié)果與“多層葉片模型”的預(yù)測結(jié)果一致。因此，在聯(lián)合氣體交換和熒光測量參數(shù)進(jìn)行數(shù)據(jù)分析時（例如，計算葉綠體內(nèi)CO2濃度），需要謹(jǐn)慎。

Light Quality Affects Chloroplast Electron Transport Rates Estimated from Chl Fluorescence Measurements

John R. Evans Patrick B. Morgan Susanne von Caemmerer

Plant and Cell Physiology, pcx103, https://doi.org/10.1093/pcp/pcx103

Abstract

Chl fluorescence has been used widely to calculate photosynthetic electron transport rates. Portable photosynthesis instruments allow for combined measurements of gas exchange and Chl fluorescence. We analyzed the influence of spectral quality of actinic light on Chl fluorescence and the calculated electron transport rate, and compared this with photosynthetic rates measured by gas exchange in the absence of photorespiration. In blue actinic light, the electron transport rate calculated from Chl fluorescence overestimated the true rate by nearly a factor of two, whereas there was closer agreement under red light. This was consistent with the prediction made with a multilayer leaf model using profiles of light absorption and photosynthetic capacity. Caution is needed when interpreting combined measurements of Chl fluorescence and gas exchange, such as the calculation of CO2partial pressure in leaf chloroplasts.