中科院華南植物園、華南師範大學和澤泉生態開放實驗室最新合作研究成果「六種亞熱帶景觀植物葉片發育過程中色素功能與反射光譜指數的變化」（Spectral reflectance parameters and pigment functions during leaf ontogenesis in six subtropical landscape plants）發表在國際著名科學雜誌Plant Growth Regulation上面。
不同發育階段葉片的葉綠素螢光成像
葉片發育過程中，其色素組成是受調節的。為了更好地了解色素的功能，本文研究了六種亞熱帶景觀植物葉片龍船花（Ixora chinensis Lam）、山茶花（Camellia japonica Linn）、紅楠木（Eugenia oleina Wight）、芒果（Mangifera indica L.）、桂花（Osmanthus fragrans Lowr）和無憂花（Saraca dives Pierre.）不同發育階段的葉綠素、類胡蘿蔔素及花色素苷含量的變化。研究發現，幼葉的花色素苷含量高，而葉綠素含量低。隨著葉片的發育，花色素苷含量逐漸降低，而六種植物的光合色素（葉綠素及胡蘿蔔素）含量均升高。φPSII和NPQ的葉綠素螢光成像及快速光響應曲線（RLC）的結果表明，葉片發育過程中，ETRmax、φPSII及RLC的飽和點升高；隨著葉片的衰老，它們又下降。與其他發育階段的葉片相比，幼葉的NPQ及Car/Chl比值較高。400-800 nm葉片反射光譜為活體無損傷檢測葉片發育過程中其色素含量的變化提供了一種方法。本文將四種與色素特徵相關的反射指數和生化定量分析結果做了比較。結果表明幼葉中花色素苷反射指數ARI與其含量呈線性相關，而標準化微分的植被參數CHL NDI與Chla濃度的正相關表現出物種依賴性。在葉片發育過程及不同的物種之間, 光合反射指數與Car/Chl沒有密切相關性，而具有結構獨立性的色素參數變化也不大。以上結果說明, 幼葉中較高的花色素苷含量, NPQ及Car/Chl比值，在光合機構沒有完全發育的情況下, 對於其應對高光輻射是非常重要的。而另外兩個葉片反射指數ARI及Chl NDI，對於在活體條件下，檢測葉片發育過程色素含量的變化是非常有價值的。（生物谷Bioon.com）
生物谷推薦原始出處：
Plant Growth Regulation DOI 10.1007/s10725-008-9353-9
Spectral reflectance indices and pigment functions during leaf ontogenesis in six subtropical landscape plants
Nan Liu1, 2, Zhi-Fang Lin1 , Anna Van Devender3, Gui-Zhu Lin1, Chang-Lian Peng1, 2, Xiao-Ping Pan1, Shao-Wei Chen1 and Qun Gu4
(1) Guangdong Key Laboratory of Digital Botanical Garden, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China
(2) College of Life Sciences, MOE Key Laboratory of Laser Life Science, South China Normal University, Guangzhou, 510631, China
(3) School of Natural Resources, College of Agriculture and Life Sciences, University of Arizona, Tucson, AZ 85721, USA
(4) Zeal Quest Scientific Technology Co. Ltd., Shanghai, 200333, China
Abstract Pigment combinations are regulated during leaf ontogenesis. To better understand pigment function, alterations in chlorophyll, carotenoid and anthocyanin concentrations were investigated during different leaf development stages in six subtropical landscape plants, namely Ixora chinensis Lam, Camellia japonica Linn, Eugenia oleina Wight, Mangifera indica L., Osmanthus fragrans Lowr and Saraca dives Pierre. High concentrations of anthocyanin were associated with reduced chlorophyll in juvenile leaves. As leaves developed, the photosynthetic pigments (chlorophyll and carotenoid) of all six species increased while anthocyanin concentration declined. Chlorophyll fluorescence imaging of ΦPSII (effective quantum yield of PSII) and of NPQ (non-photochemical fluorescence quenching) and determination of electron transport rate-rapid light curve (RLC) showed that maximum ETR (leaf electron transport rate), ΦPSII and the saturation point in RLC increased during leaf development but declined as they aged. Juvenile leaves displayed higher values of NPQ and Car/Chl ratios than leaves at other developmental stages. Leaf reflectance spectra (400–800 nm) were measured to provide an in vivo non-destructive assessment of pigments in leaves during ontogenesis. Four reflectance indices, related to pigment characters, were compared with data obtained quantitatively from biochemical analysis. The results showed that the ARI (anthocyanin reflectance index) was linearly correlated to anthocyanin concentration in juvenile leaves, while a positive correlation of Chl NDI (chlorophyll normalized difference vegetation index) to chlorophyll a concentration was species dependent. Photosynthetic reflectance index was not closely related to Car/Chl ratio, while a structural-independent pigment index was not greatly altered by leaf development or species. Accordingly, it is suggested that the high concentration of anthocyanin, higher NPQ and Car/Chl ratio in juvenile leaves are important functional responses to cope with high radiation when the photosynthetic apparatus is not fully developed. Another two leaf reflectance indices, ARI and Chl NDI, are valuable for in vivo pigment evaluation during leaf development.