CSB353H1 Lecture Notes - Lecture 2: Chitin, Sporangium, Plasmodesma
28 Apr 2016
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Go in plants, make spores, release hyphae, which turn into sporangium, spread to other plants or soil to find new host. Due to this layer, when use dye, gram - doesn"t dye much; gram + dyes and becomes purple. Main genera of bacterial plant pathogens pseudomonas (gram -), eg. p syringae xanthomonas (gram -), eg. x. campestris. Majority of plant pathogenic bacteria are unicellular; some are filamentous. Genes required to be plant pathogens, are often acquired from other, unrelated plant pathogens. Bacteria often enter through natural openings, eg. stomata proliferate and create nest in intercellular spaces secrete gooey stuff, extracellular polysaccharide material (eps), which protect against plant antimicrobial attack. Produce toxins and enzymes to damage plant tissue. Tabtoxin produced by p. syringae tabaci is hydrolyzed in plant cell to produce tabtoxinine (active form) Targeted mutagenesis shows that toxins aren"t essential for pathogenesis; however, tab mutant shows reduced virulence.
