Molecular Genetic Analysis of the Regulation of Photosynthesis under low CO2 Conditions

低CO2条件下光合作用调控的分子遗传学分析

• 批准号: 11640648
• 负责人: SHIKANAI Toshiharu
• 金额: $ 2.24万
• 依托单位: NARA INSTITUTE OF SCIENCE AND TECHNOLOGY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11640648/
• 关键词: photosynthesis; photosynthetic electron flow; CO2; chloroplast; photoinhibition; chlorophyll fluorescence; Arabidopsis; genetics; 光科学系I; 変異株; シロイヌナズナ; 光化学系I; 活性酸素; 乾燥ストレス; 酸化ストレス; Arabidopsis thaliana; 突然変異; カロテノイド; カロチノイド; 突然変異株

The plants in the field often encounter low concentration of CO2 in the Chloroplast by the stomata closure responding to the drought stress. Absorbance of light energy under the conditions leads to the generation of active oxygen species, causing photoinhibition. Plants have multiple mechanisms to avoid photoinhibition under the low CO2 conditions. In this project we have modified the chlorophyll fluorescence imaging system to facilitate the isolation of Arabidopsis mutant defective in the dissipation of excessive light energy safely as heat (thermal dissipation). We identified mutants allelic to npq2 and npq4 which are defective in the machinery of thermal dissipation. The results confirmed the physiological significance of thermal dissipation to alleviate the stress of low CO2 concentration.Arabidopsis mutant pgr5 was isolated depending on the defect to induce thermal dissipation at high light intensity. Pgr5 also cannot induce thermal dissipation in the CO2-free air. Pgr5 is defective in the activity of cyclic electron flow around PSI. The physiological function has been unclear for long and the gene PGR5 participates in the pathway was first identified. The PGR5-dependent cyclic electron flow around PSI is essential to protect photosynthetic machineries under low CO2 concentration conditions.

田间的植物经常通过对干旱胁迫的气孔闭合在叶绿体中遇到低浓度的二氧化碳。在条件下轻能的吸光度会导致活性氧的产生，从而导致光抑制。植物具有多种机制，可以避免在低二氧化碳条件下进行光抑制。在这个项目中，我们修改了叶绿素荧光成像系统，以促进拟南芥突变体在耗散过多的光能（热量耗散）中的耗散中分离出。我们确定了在热耗散机械中有缺陷的NPQ2和NPQ4的突变体等位基因。结果证实了热耗散以减轻低二氧化碳浓度的应力的生理意义。阿拉比托匹泊突变体PGR5根据缺陷，以高光强度诱导热耗散。 PGR5也不能在无二氧化碳空气中诱导热耗散。 PGR5在PSI周围的环状电子流的活性中有缺陷。长期尚不清楚生理功能，并且首先确定了基因PGR5参与该途径。 PSI周围的PGR5依赖性循环电子流对于在低二氧化碳浓度条件下保护光合制度至关重要。

项目成果

Shikanari T., Shimizu K., Ueda K., Nishimura Y., Kuroiwa T. and Hashimoto T.: "The chloroplast clpP gene, encoding a proteolytic subunit of ATP-dependent protease, is indispensable for chloroplast development in tobacco"Plant Cell Physiol.. 42. 264-273 (2

Shikanari T.、Shimizu K.、Ueda K.、Nishimura Y.、Kuroiwa T. 和 Hashimoto T.：“叶绿体 clpP 基因编码 ATP 依赖性蛋白酶的蛋白水解亚基，对于烟草叶绿体发育是不可或缺的”Plant Cell

Munekage Y., Hojo M., Meure J., Endo T., Tasaka M. and Shikanari T.: "PGR5 is involved in cyclic electron flow around photosystem I and is essential for photoprotection in Arabidopsis"Cell. 110. 361-371 (2002)

Munekage Y.、Hojo M.、Meure J.、Endo T.、Tasaka M. 和 Shikanari T.：“PGR5 参与光系统 I 周围的循环电子流，对于拟南芥细胞的光保护至关重要。”

Munekage Y., Takeda S., Endo T., Jahns P., Hashimoto T. and Shikanari T.: "Cytochrome b_6f mutation specifically affects thermal dissipation of absorbed light energy in Arabidopsis"Plant J.. 28. 351-359 (2001)

Munekage Y.、Takeda S.、Endo T.、Jahns P.、Hashimoto T. 和 Shikanari T.：“细胞色素 b_6f 突变特别影响拟南芥吸收光能的热耗散”Plant J.. 28. 351-359 (2001

Munekage Y., Hojo M., Meure J., Endo T., Tasaka M., Shikanai T.: "PGR5 is involved in cyclic electron flow around photosystem I and is essential for photoprotection in Arabidopsis"Cell. 10. 361-371 (2002)

Munekage Y.、Hojo M.、Meure J.、Endo T.、Tasaka M.、Shikanai T.：“PGR5 参与光系统 I 周围的循环电子流，对于拟南芥细胞的光保护至关重要。”

Shikanai T., Muunekage Y., Shimizu K., Endo T., Hashimoto T.: "Identification and characterization of Arabidopsis mutants with reduced quenching of chlorophyll fuluorescence"Plant Cell Physiol. 40. 1134-1142 (1999)

Shikanai T.、Muunekage Y.、Shimizu K.、Endo T.、Hashimoto T.：“叶绿素荧光猝灭减少的拟南芥突变体的鉴定和表征”植物细胞生理学。