Ca2+-regulated cyclic electron flow supplies ATP for nitrogen starvation-induced lipid biosynthesis in green alga

• DOI: 10.1038/srep15117
• Publication Date: 2015-10-09T09:38:02Z
• Authors: Hui Chen; Jinlu Hu; Yaqin Qiao; Weixian Chen; Junfeng Rong; Yunming Zhang; Chenliu He; Qiang Wang
• Keywords: Electron flow

Abstract We previously showed that both the linear photosynthetic electron transportation rate and respiration dropped significantly during N starvation-induced neutral lipid accumulation in an oil-producing microalga, Chlorella sorokiniana proposed a possible role for cyclic flow (CEF) ATP supply. In this study, we further exploited hypothesis C3 model green alga Chlamydomonas . found of CEF around photosystem I activity thylakoid membrane-located synthetase increased starvation to drive production. Furthermore, demonstrated mutant pgrl1, which is deficient PGRL1-mediated CEF, accumulated less lipids had reduced rates under starvation. Further analysis revealed Ca 2+ signaling regulates biosynthesis by increasing calmodulin boosting expression calcium sensor protein Pgrl1-mediated CEF. Thus, -regulated supplies alga. The may re-equilibrate ATP/NADPH balance recycle excess light energy photosystems prevent photooxidative damage, suggesting also played key protecting sustaining photosystems.