ibclogo XVI International Botanical Congess


Abstract Number: 4807
Poster No. = 1769


FUNCTIONAL ANALYSIS OF TWO CHROMOSOMAL VIRULENCE GENES, chvA and acvB, OF AGROBACTERIUM TUMEFACIENS USING AVIRULENT MUTANTS WITH A TRANSPOSON 5 INSERTION IN RESPECTIVE GENE.


Parimal Majumder, Kenichiro Takagi, Hidenari Shioiri, Masayuki Nozue, and Mineo Kojima. Department of Applied Biology, Faculty of Textile Science and Technology, Shinshu University, 3-15-1, Tokida, Ueda, Nagano 386-8567, Japan


A mutant (M3 strain) of Agrobacterium tumefaciens was isolated by transposon (Tn5) mutagenesis. The M3 strain was avirulent on all host plants tested, Daucus carota, Solanum tuberosum and Kalanchoe pinnata. Using M3 (chvA::Tn5), B119 (acvB::Tn5) and A208 (parent, virulent) strains, the functions of chvA and acvB genes were analyzed. The aall three strains were co-cultured with tobacco BY2 suspension cells with/without acetosyringone (As), efficient T-DNA transfer was found only with A208 strain in presence of As. However, T-strang was produced normally in all strains in presence of As. Analyses with tricine-SDS-PAGE and electron microscopy demonstrated that pili were not produced on cell surface of M3 strain in media with/without As. On the other hand, in presence of As, Aperfect@ and Aimperfect@ pili were produced on A208 and B119 strains, respectively. Taken together these results, chvA and acvB likely play roles in virulence through influence on formation of pili through which T-strands are transferred to host cells. Key words: Agrobacterium tumefaciens, chromosomal virulence gene, functional analysis of gene, transposon tagging, tobacco BY2 cell.


HTML-Version made 7. July 1999 by Kurt Stüber