Trophic status of Chlamydomonas reinhardtii influences the impact of iron deficiency on photosynthesis

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• 作者：Aimee M. Terauchi ; Graham Peers ; Marilyn C. Kobayashi ; Krishna K. Niyogi and Sabeeha S. Merchant
• 关键词：Acetate ; Algae ; LhcSR ; Non ; photochemical quenching ; Respiration
• 刊名：Photosynthesis Research
• 出版年：2010
• 出版时间：July, 2010
• 年：2010
• 卷：105
• 期：1
• 页码：39-49
• 全文大小：457.0 KB

文摘

To investigate the impact of iron deficiency on bioenergetic pathways in Chlamydomonas, we compared growth rates, iron content, and photosynthetic parameters systematically in acetate versus CO₂-grown cells. Acetate-grown cells have, predictably (2-fold) greater abundance of respiration components but also, counter-intuitively, more chlorophyll on a per cell basis. We found that phototrophic cells are less impacted by iron deficiency and this correlates with their higher iron content on a per cell basis, suggesting a greater capacity/ability for iron assimilation in this metabolic state. Phototrophic cells maintain both photosynthetic and respiratory function and their associated Fe-containing proteins in conditions where heterotrophic cells lose photosynthetic capacity and have reduced oxygen evolution activity. Maintenance of NPQ capacity might contribute to protection of the photosynthetic apparatus in iron-limited phototrophic cells. Acetate-grown iron-limited cells maintain high growth rates by suppressing photosynthesis but increasing instead respiration. These cells are also able to maintain a reduced plastoquinone pool.