BOT 4734C Chapter Notes - Chapter 2: Plant Cell, Plasmid, Chromosome
Document Summary
Genomic structure of agrobacterium: total of three genetic components in agrobacterium required for plant transformation. 35-kb virulence (vir) region on another plasmid. Seven major loci: vira, b, c, d, e, g, h. Respond to compounds secreted by a wounded plant (infects plant wounds) Chromosomal virulence (chv) region on agrobacterium chromosome. Bacterial attraction and attachment to wounded plant cells. T-dna borders (right and left) define the dna fragment to be transferred (rb) gtttacccgccaatatatcctgtca------------------- Path of dna transport: from agrobacterium to nucleus of plant cell. Bacteria loosely bind to host cell surface. Bound bacteria synthesize cellulose filaments, leading to tight association. Signal transduction between bacteria and host plant cells. Plant signals: wounded cells, sap ph 5~5. 8, various phenolic compounds (acetosyringone: stimulate agrbacterium vir a/g gene expression. Vira phosphorylates virg: virg activates other vir gene expression. Vir proteins lead to production of a linear single-stranded copy of t-dna. One vird2 and ~600 vire2 attached to one t-dna (t-complex)
