2013 Fiscal Year Final Research Report
Elucidation of the role of the vacuolar type proton pyrophosphatase in early stages of plant development
| Project/Area Number |
24770039
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Plant molecular biology/Plant physiology
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| Research Institution | Tokyo Gakugei University |
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Principal Investigator |
FERJANI Ali 東京学芸大学, 教育学部, 准教授 (20530380)
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| Project Period (FY) |
2012-04-01 – 2014-03-31
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| Keywords | H+PPase / fugu5変異体 / 代謝制御 / ピロリン酸 / ショ糖 / 糖新生 / 補償作用 / 葉の発生 |
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| Research Abstract |
Following germination, oil-seed plants rely on triacylglycerol (TAG) reserves for growth during a heterotrophic period, where TAG is converted to sucrose (Suc). Also, macromolecular syntheses consume huge amounts of ATP, often hydrolyzed to AMP plus PPi. In Arabidopsis, the vacuolar H+-PPase uses energy from PPi hydrolysis to acidify the vacuole. The fugu5 mutants, lacking the AVP1 H+-PPase, failed to sustain postgerminative heterotrophic growth; recovered upon Suc supply, or specific PPi removal by the cytosolic PPase IPP1. Thus the major function of H+-PPase in seedling development is the removal of inhibitory PPi, rather than H+ pumping. Suc and PPi quantification in WT versus fugu5 indicated that gluconeogenesis is inhibited by elevated level of PPi, but the targets of PPi inhibition remained unclear. Here, profiling of major metabolites that occur during TAG mobilization showed that UDP-Glucose Pyrophosphorylase (UGPase) is specifically inhibited by excess cytosolic PPi in fugu5.
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