| Abstract Detail
Conference Wide Kandel- Kfir, Michal [1], Swartzberg, Dvora [1], Damari-Weissler, Hila [1], German, Marcelo A [2], Gidoni, David [1], Mett, Anahit [1], Belausov, Eddy [1], Veramendi, Jon [3], Adir, Noam [4], Granot, David [5]. Tomato hexokinases and sugar signaling. HEXOKINASES (HXK) catalyze hexose phosphorylation, the first step of sugar metabolism. Expression of Arabidopsis hexokinase AtHXK1 in photosynthetic tissues of tomato plants causes sugar signaling effects independent of its downstream product, Glucose-6-phosphate. However, work done with potato raised doubts whether Solanacea HXKs have similar roles. To address this question we cloned and analyzed the tomato HXK genes and examined the effect of Solanacea HXKs in tomato plants. Four HXK genes from tomato plants have been isolated and characterized. These genes encode three membrane associated HXKs and a plastidic HXK. Interestingly, although the 4 HXK genes are expressed in all tissues examined, their expression in leaves is very low. Nevertheless, antisense suppression of tomato LeHXK1 and LeHXK2 inhibited expression of photosynthetic genes and delayed leaf senescence, while overexpression of these genes increased expression of photosynthetic genes and accelerated senescence, implying a signaling role of the native Solanacea HXK in leaves of tomato plants.
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1 - Volcani Center, Vetebale Research, P.O. Box 6, Bet Dagan, 50250, Israel
2 - Delaware Biotechnology Institute, Newark, DE, 19711, USA
3 - Universidad Publica de Navarra, Pamplona, , Spain
4 - Technion - Israel Institute of Technology, Chemistry, Haifa, , Israel
5 - Volcani Center, Vegetable Research, Bet Dagan, 50250, Israel
Keywords:
sugar sensing
hexose phosphorylation
hexokinase
Intracellular localization.
Session: Poster-143
Location: Ballroom CD/Monona Terrace
Date: Tuesday, July 25th, 2006
Time: 8:00 AM
Abstract ID:341 |
