| Abstract Detail
Conference Wide Omura, Toshikazu [1], Watanabe, Shin [2], Frasse, Pierre [3], Iijima, Yoko [4], Aoki, Koh [4], Bouzayen, Mondher [3], Shibata, Daisuke [4], Ezura, Hiroshi [2]. Over-expression of melon HMGR leads negative feedback regulation of native HMGRs transcription and increased fruits size in tomato. 3-HYDROXY-3-METHYLGLUTARYL CoA reductase (HMGR) catalysis the conversion of HMG CoA into mevalonate, and is assumed to be the rate limiting step of isoprenoid biosynthetic pathway. In plants, over 23000 of isoprenoid components, such as phytohormons, chlorophyll, defense-related compounds and phytosterols are produced through this pathway. These components plays essential role in plant normal growth; for example, reduced level of HMGR leads dwarf phenotype and/or smaller fruit size in several plant species. However, neither the factors which affect the fruit growth nor the detailed regulation system of HMGR, such as transcription, translation, modification and degradation, are not known yet. To obtain deeper insight of the mechanisms, HMGR gene isolated from melon (Cucumis melo L. reticulatus) was introduced into tomato (Lycopersicon esculentum Mill. cv. Moneymaker) and the transgenic tomato was grown in the greenhouse. The transformant bore significantly larger fruits, more than 20% by weight. For transcriptional analysis, the fruits were collected at the four different developmental stages and the pericarp was used for the experiments. The RT-PCR southern blot analysis revealed that the expression level of Le-HMGR1 and Le-HMGR2 in transgenic tomato is lower in all stages. Besides, the different expression levels of the genes downstream of HMGR were not detected between wild-type and transformant by the DNA array analysis. Those results suggest that the over-expression of Cm-HMGR or increased isoprenoid components might affect the Le-HMGRs at the transcription level.
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1 - University of Tsukuba, Graduate School of Life and Environmental Sciences, 304 Gene Research Center, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8572, Japan
2 - University of Tsukuba, Gene Research Center, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8572, Japan
3 - Institut National de la Recherche Agronomique/Institut National Polyte, Castanet-Tolosan Cedex, Toulouse, 31326, France
4 - Kazusa DNA Research Institute, Dept. Plant Gene Research, 2-6-7 Kazusa-Kamatari, Kisarazu, Chiba, 292-0818, Japan
Keywords:
Fruit weight
Lycopersicon
HMGR.
Session: Poster-120
Location: Ballroom CD/Monona Terrace
Date: Tuesday, July 25th, 2006
Time: 8:00 AM
Abstract ID:220 |
