Abstract
The aim of this work was to investigate the role of fructose 2,6-bisphosphate (Fru 2,6-P2) during photosynthesis. The level of Fru 2,6-P2 in tobacco plants was elevated by the introduction of a modified mammalian gene encoding 6-phosphofructo-2-kinase (6-PF-2-K). Estimates of the metabolite control coefficient (C) for Fru 2,6-P2 levels in response to increased 6-PF-2-K activity, suggest that small increases in 6-PF-2-K activity have little effect upon steadystate Fru 2,6-P2 levels (C = +0.08 for a 0-58% increase in 6-PF-2-K activity). However, larger changes resulted in dramatic rises in Fru 2,6-P2 levels (C = +3.35 for 206-268% increase in 6-PF-2-K activity). Transgenic plants contained Fru 2,6-P2 levels in the dark that ranged from 104 to 230% of the level in wild-type tobacco. Plants with altered levels of Fru 2,6-P2 were used to determine the effects of this signal metabolite upon carbohydrate metabolism during the initial phase of the light period. Here we provide direct evidence that Fru 2,6-P2 contributes to the regulation of carbon partitioning in tobacco leaves by inhibiting sucrose synthesis.
Original language | English (US) |
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Pages (from-to) | 461-469 |
Number of pages | 9 |
Journal | Plant Journal |
Volume | 7 |
Issue number | 3 |
State | Published - Mar 1995 |