||Juntaro Negi, Boseok Song, Sho Yamagaki, Koh Iba, Guard cell chloroplasts develop a unique lipid metabolism essential for CO2 and light responses, Keystone Symposium (Climate Change-linked Stress Tolerance), 2019.05.
||Juntaro Negi, Shintaro Munemasa, Boseok Song, Ryosuke Tadakuma, Mayumi Fujita, Tamar Azoulay-Shemer, Cawas B. Engineer, Kensuke Kusumi, Ikuo Nishida, Julian I. Schroeder, Koh Iba, Stomatal Guard Cells Exhibit a Unique Lipid Metabolism Essential for Functional Chloroplasts to Sense CO2 and Light Signals, The 23rd International Symposium on Plant Lipids (ISPL2018), 2018.07.
||Boseok Song, Sho Yamagaki, Koh Iba, Juntaro Negi, Isolation and characterization of the guard-cell-specific achlorophyllous mutants in Arabidopsis, The International Conference on Arabidopsis Research (ICAR) 2018, 2018.06.
||Juntaro Negi, Shintaro Munemasa, Boseok Song, Ryosuke Tadakuma, Mayumi Fujita, Tamar Azoulay-Shemer, Cawas B. Engineer, Kensuke Kusumi, Ikuo Nishida, Julian I. Schroeder, Koh Iba, Eukaryotic lipid metabolic pathway is essential for functional chloroplasts and CO2 and light responses in stomatal guard cells, The International Conference on Arabidopsis Research (ICAR) 2018, 2018.06.
||Juntaro Negi, Makoto Okabe, Yuhei Ono, Natsumi Hoshino, Ikuo Nishida, Koh Iba, A rate-limiting enzyme in phosphatidylethanolamine biosynthesis, PECT1, is involved in the stomatal regulation in Arabidopsis, The International Conference on Arabidopsis Research (ICAR) 2016, 2016.07, An Arabidopsis mutant with impaired stomatal response to CO2, cdi4 (carbon dioxide insensitive 4), was isolated by a high-throughput leaf thermal imaging screening. Positional cloning revealed that the cdi4 mutation is localized within a coding region of PECT1 which encodes CTP:phosphorylet hanolamine cytidylyltransferase, the rate-limiting enzyme in phosphatidyle thanolamine (PE) biosynthesis pathway. PE is the major phospolipid species in all plant membranes except plastid membranes, and PECT1 is essential for plant embryogenesis. The role of PECT1 in stomatal response to environmental cues remains undefined. The cdi4 mutant had a defect in stomatal movement, including high CO2-induced stomatal closing and low CO2- and light-induced stomatal opening. The PECT1-overexpression line had an increase in transpiration rate at low CO2 and light. GUS-reporter analysis showed that the PECT1 is expressed in all plant tissues, including the guard cells. When the PECT1 was repressed by antisense RNA in a guard cell–specific manner, the stomatal CO2 response was partially repressed. These results suggest that the role of PECT1 in guard cells is important for CO2-induced stomatal movement. The cdi4 mutant had a decrease in PE levels, indicating that PE levels may affect CO2-induced stomatal movement in Arabidopsis..
||Juntaro Negi, Kosuke Moriwaki, Mineko Konishi, Ryusuke Yokoyama, Toshiaki Nakano, kensuke kusumi, Mimi Hashimoto-Sugimoto, Julian I. Schroeder, Kazuhiko Nishitani, Shuichi Yanagisawa, Koh Iba, SCAP1, a master regulator of the development of functional stomata in Arabidopsis, International Workshop on Plant Membrane Biology (IWPMB2013), 2013.03.