1997 Fiscal Year Final Research Report Summary
Study on development of a new transgenic tomato plant having self-incompatibility gene from wild species.
| Project/Area Number |
07556074
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
Breeding science
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| Research Institution | Mie University |
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Principal Investigator |
KOWYAMA Yasuo Mie University, Faculty of Bioresources, Professor, 生物資源学部, 教授 (80024579)
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| Co-Investigator(Kenkyū-buntansha) |
HIRAI Masashi Institute of Vegetables, Tea and Ornamental Flowers, MAFF,Chief Researcher of La, 野菜茶業試験場, 研究室長
IMANISHI Sigeru Yamagata University, Faculty of Agriculture, Professor, 農学部, 教授 (40007084)
HATTORI Tsukaho Mie University, Center for Molecular Biology and Genetics, Associate Professor, 遺伝子実験施設, 助教授 (10164865)
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| Project Period (FY) |
1995 – 1997
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| Keywords | Tomato / Self-incompatibility / Gene Transfer / Transgenic plant / Ribonuclease / S-RNase |
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| Research Abstract |
The present study aims to develop a new technique of molecular breeding for production of transgenic tomato genotypes having self-incompatibility gene originated from wild species of tomato, and for genetical control of plant reproduction by means of Agrobacterium-mediated gene transfer method. Solanaceous plants including wild relatives of tomato possess a gemetophytic self-incompatibility regulated by a single locus with multiple alleles (S-gene). The S-gene encodes a ribonuclease (S-RNase) that specifically expresses in pistil tissues of plant. A lot of cDNA clones and genomic clones encoding S-RNase have been reported from solanaceous plant species, e.g., Nicotiana, Petunia and Lycopersicon. On the other hand, the cultivated tomato plants are self-compatible, and genetic mechanisms leading to it's self-compatibility are not known. From research results of the present study, it was shown that in genetic transformants of a tomato cultivar "Aki-Tama" obtained through Agrobacterium- infected leaf-disks, the introduced S-RNase gene was identified as a single copy in the genome by Southern hybridization, and expressed specifically in the style tissue, as shown by Northern blot a malysis. The expressin level of the introduced gene was, however, very low, when compared with the wild species. This suggests that promoter region (lkbp of 5'-upstream region from ORF of S-RNase) used for construction of the Ti-vector is sufficient for tissue-specific expression, but not enough for enhancement of gene expression level. From RNase-activity staining after SDS-PAGE of stylar proteins, almost no activity of S-RNase was detected in tomato cultivars, indicating that self-compatibility of tomato is due to a low level of S-RNase activity in the style.
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