Downregulation of the δ-Subunit Reduces Mitochondrial ATP Synthase Levels, Alters Respiration, and Restricts Growth and Gametophyte Development in Arabidopsis
Downregulation of the δ-Subunit Reduces Mitochondrial ATP Synthase Levels, Alters Respiration, and Restricts Growth and Gametophyte Development in Arabidopsis
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DOI：
10.1105/tpc.112.099424
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发表时间：
2012-07-01
期刊：
影响因子：
11.6
通讯作者：
Persson, Staffan
中科院分区：
文献类型：
--
作者：
Geisler, Daniela A.;Paepke, Carola;Persson, Staffan
线粒体ATP合成酶（F1 Fo complex）是一种进化上保守的多聚体蛋白复合物，主要合成胞浆ATP，但其调控机制在植物中的研究还很有限。在酵母中，δ-亚基将膜包埋的F-1部分连接到F-1的面向基质的中心柄。我们使用遗传干扰和抑制剂来研究拟南芥δ亚基的分子功能和生理影响。Delta突变体显示出雄性和雌性配子体缺陷。RNA干扰的δ导致生长迟缓，ATP合酶的量减少，并增加替代氧化酶的能力，并导致特定的长期增加的丙氨酸和甘氨酸水平。相比之下，使用寡霉素的复合物的抑制引发了广泛的代谢变化，影响糖酵解和三羧酸循环，并导致替代呼吸途径和氧化还原和生物应激相关转录因子的转录物的连续诱导。我们的结论是：（1）δ-亚基是必需的雄配子体发育在拟南芥，（2）ATP合酶的干扰似乎会导致一个早期的过渡阶段和一个长期的代谢稳定状态，（3）所观察到的线粒体代谢的长期调整与减少生长和配子体发育的缺陷。
The mitochondrial ATP synthase (F1Fo complex) is an evolutionary conserved multimeric protein complex that synthesizes the main bulk of cytosolic ATP, but the regulatory mechanisms of the subunits are only poorly understood in plants. In yeast, the delta-subunit links the membrane-embedded F-o part to the matrix-facing central stalk of F-1. We used genetic interference and an inhibitor to investigate the molecular function and physiological impact of the delta-subunit in Arabidopsis thaliana. Delta mutants displayed both male and female gametophyte defects. RNA interference of delta resulted in growth retardation, reduced ATP synthase amounts, and increased alternative oxidase capacity and led to specific long-term increases in Ala and Gly levels. By contrast, inhibition of the complex using oligomycin triggered broad metabolic changes, affecting glycolysis and the tricarboxylic acid cycle, and led to a successive induction of transcripts for alternative respiratory pathways and for redox and biotic stress-related transcription factors. We conclude that (1) the delta-subunit is essential for male gametophyte development in Arabidopsis, (2) a disturbance of the ATP synthase appears to lead to an early transition phase and a long-term metabolic steady state, and (3) the observed long-term adjustments in mitochondrial metabolism are linked to reduced growth and deficiencies in gametophyte development.