Crown gall disease caused by Agrobacterium via plant transformation

(a) Ogrcgsgenic cytokinin Opine Right T-DNA g - production . border (ZS-hp AUX") syntheSIS imperfect production repeats) Left T-DNA ' ’ " ‘ Genes for border ' conjugative (2543p m transfer imperfect ' repeats) \ Tumor-inducing (Ti) plasmid Genes for opine catabolism (required for utilization of amino acids) Virulence region (genes required for efficient DNA . transfer) or! 1 Transfer DNA (T-DNA) contains auxin and cytokinin biosynthetic genes and genes for amino acid biosynthesis. (b) Agrobacterium tumefaciens Plant cell (1-2 microns wide) (5—50 microns wide) Ti plasmid Virulence " proteins 3‘ A single strand of T-DNA is transferred into the plant ‘ cell and IS integrated into the plant nuclear genome. j (e) ExpresSion of auxin and cytokinin biosynthetic genes leads to uncontrolled cell division and gall formation; gall cells produce the unusual amino acids that Agrobacten'um uses as carbon and nitrogen sources.