Eukaryotic lipid metabolic pathway is essential for functional chloroplasts and CO(2) and light responses in Arabidopsis guard cells.
Eukaryotic lipid metabolic pathway is essential for functional chloroplasts and CO(2) and light responses in Arabidopsis guard cells.
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真核脂质代谢途径对于拟南芥保卫细胞的功能性叶绿体、CO(2) 和光反应至关重要。
DOI：
10.1073/pnas.1810458115
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发表时间：
2018-09-04
影响因子：
11.1
通讯作者：
Iba K
中科院分区：
文献类型：
--
作者：
Negi J;Munemasa S;Song B;Tadakuma R;Fujita M;Azoulay-Shemer T;Engineer CB;Kusumi K;Nishida I;Schroeder JI;Iba K
Guard cells have photosynthetically active chloroplasts in most plant species. However, the significance of their existence in guard cells or their developmental mechanisms is unknown. Here, through a forward-genetic approach, we have identified a key feature and a function of guard cell chloroplasts. We observed that a mutation that impaired chloroplast biogenesis in guard cells also disrupted the regulation of stomatal movements by CO2 and light. We demonstrated that guard cell chloroplasts, compared with those in mesophyll cells, display a unique lipid metabolism, in which the prokaryotic pathway is diminished and the eukaryotic pathway gains control. Our findings highlight the importance of the eukaryotic pathway for developing functional chloroplasts in guard cells. Stomatal guard cells develop unique chloroplasts in land plant species. However, the developmental mechanisms and function of chloroplasts in guard cells remain unclear. In seed plants, chloroplast membrane lipids are synthesized via two pathways: the prokaryotic and eukaryotic pathways. Here we report the central contribution of endoplasmic reticulum (ER)-derived chloroplast lipids, which are synthesized through the eukaryotic lipid metabolic pathway, in the development of functional guard cell chloroplasts. We gained insight into this pathway by isolating and examining an Arabidopsis mutant, gles1 (green less stomata 1), which had achlorophyllous stomatal guard cells and impaired stomatal responses to CO2 and light. The GLES1 gene encodes a small glycine-rich protein, which is a putative regulatory component of the trigalactosyldiacylglycerol (TGD) protein complex that mediates ER-to-chloroplast lipid transport via the eukaryotic pathway. Lipidomic analysis revealed that in the wild type, the prokaryotic pathway is dysfunctional, specifically in guard cells, whereas in gles1 guard cells, the eukaryotic pathway is also abrogated. CO2-induced stomatal closing and activation of guard cell S-type anion channels that drive stomatal closure were disrupted in gles1 guard cells. In conclusion, the eukaryotic lipid pathway plays an essential role in the development of a sensing/signaling machinery for CO2 and light in guard cell chloroplasts.
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影响因子：
9.2
作者：
Negi, Juntaro;Moriwaki, Kosuke;Konishi, Mineko;Yokoyama, Ryusuke;Nakano, Toshiaki;Kusumi, Kensuke;Hashimoto-Sugimoto, Mimi;Schroeder, Julian I.;Nishitani, Kazuhiko;Yanagisawa, Shuichi;Iba, Koh
通讯作者：
Iba, Koh
影响因子：
7.4
作者：
Heilmann, I;Mekhedov, S;Shanklin, J
通讯作者：
Shanklin, J
影响因子：
7.4
作者：
Kim, HU;Huang, AHC
通讯作者：
Huang, AHC
影响因子：
20.5
作者：
Engineer CB;Hashimoto-Sugimoto M;Negi J;Israelsson-Nordström M;Azoulay-Shemer T;Rappel WJ;Iba K;Schroeder JI
通讯作者：
Schroeder JI
DOI：
10.1111/tpj.12916
发表时间：
2015-08
期刊：
The Plant journal : for cell and molecular biology
影响因子：
--
作者：
Azoulay-Shemer T;Palomares A;Bagheri A;Israelsson-Nordstrom M;Engineer CB;Bargmann BO;Stephan AB;Schroeder JI
通讯作者：
Schroeder JI