Poster: Vegetative Development
Abs #
430: Cloning and characterization of the genes developmentally regulated during storage root formation of sweet potato
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Presenter: |
Tanaka, Masaru , mtanaka@affrc.go.jp |
Authors | Tanaka, Masaru (A) Yasuhiro, Takahata (A) Makoto, Nakatani (B) | | Affiliations: |
(A): Department of Upland Farming Research, National Agricultural Research Center for Kyushu Okinawa region
(B): Department of Field Crop Research, National Institute of Crop Science
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| Web Site: | http://ss.knaes.affrc.go.jp/index.html | |
The high productivity of sweet potato (Ipomoea batatas) is due to the sink potential of storage root. Although the process of storage root formation has been studied anatomically and physiologically, its molecular basis is unknown. To identify the genes involved in storage root formation, we carried out the differential display analysis on the adventitious roots in different developmental stages of storage root. A total of 26 arbitrary primers were tested, and the amplified fragments showing developmentally regulated expression were cloned. The expression patterns of the cloned fragments were confirmed by semiquantitative RT-PCR analysis. We identified 10 genes developmentally regulated and named them SRF1-SRF10. The expression of SRF1, 2, 3, 5, 6, 7, and 9 increased during storage root formation, whereas the expression of SRF4, 8, and 10 decreased. For further characterization, full-length cDNA of SRF1 and SRF6 were isolated from the cDNA library of storage root. The deduced amino acid sequence of SRF6 was similar to the somatic embryogenesis receptor-like kinase (SERK). Phylogenetic analysis based on the amino acid sequences of protein kinase domain showed that SRF6 protein formed a distinct group with several hypothetical proteins of Arabidopsis thaliana. The deduced amino acid sequence of SRF1 had structural characteristics of group II Dof zinc finger protein. Semiquantitative RT-PCR analysis showed that the mRNA of SRF1 and SRF6 were most abundantly expressed in the storage roots, although a certain amount of expression was also observed in other vegetative organs. It is possible that these genes have roles in the signaling process during storage root formation. We are now analyzing the spatial expression of these genes by in situ hybridization.
