Elevated atmospheric CO₂ mitigated photoinhibition in a tropical tree species, Gmelina arborea

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• 作者：Girish Kumar Rasineni^a ; Anirban Guha^a ; Attipalli Ramachandra Reddy ; ^a ; ^{arrsl@uohyd.ernet.in}
• 关键词：Chlorophyll a fluorescence ; Elevated CO₂ ; Gmelina arborea ; Photosynthesis ; PSII efficiency
• 刊名：Journal of Photochemistry and Photobiology B: Biology
• 出版年：2011
• 出版时间：3 May 2011
• 年：2011
• 卷：103
• 期：2
• 页码：159-165
• 全文大小：680 K

文摘

Effects of elevated CO₂ on photosynthetic CO₂ assimilation, PSII photochemistry and photoinhibition were investigated in the leaves of a fast growing tropical tree species, Gmelina arborea (Verbenaceae) during summer days of peak growth season under natural light. Elevated CO₂ had a significant effect on CO₂ assimilation rates and maximal efficiency of PSII photochemistry. Chlorophyll a fluorescence induction kinetics were measured to determine the influence of elevated CO₂ on PSII efficiency. During midday, elevated CO₂-grown Gmelina showed significantly higher net photosynthesis (p < 0.001) and greater F_V/F_M (p < 0.001) than those grown under ambient CO₂. The impact of elevated CO₂ on photosynthetic rates and Chl a fluorescence were more pronounced during midday depression where the impact of high irradiance decreased in plants grown under elevated CO₂ compared to ambient CO₂-grown plants. Our results clearly demonstrate that decreased susceptibility to photoinhibition in elevated CO₂ grown plants was associated with increased accumulation of active PSII reaction centers and efficient photochemical quenching. We conclude that elevated CO₂ treatment resulted in easy diminution of midday photosynthetic depression.