Tab A - Page 30 
5. Phytotoxins 
Strains of _P. s_. syrinqae produce low molecular weight peptide phytotoxins 
(syrlngomycln or syringotoxln . depending on their host of origin). Several 
reports suggest that these toxins are either required or accessory factors for 
pathogenicity on most, but apparently not on all hosts of £. s_. syrinoae . 
Among over 100 isolates recently tested in the laboratory of Dr. Lindow, 
approximately 50 percent did not produce these toxins in culture. Many 
Isolates are known to lose toxin production readily. Strains that do not 
produce toxins will be used in the proposed field tests. (I) 
B. Erwinia herbicola 
E_. herbicol a comprises yellow pigmented bacteria commonly epiphytic on 
plants. Although E_. herbicola is commonly found in association with diseased 
tissue, it is mostly an opportunistic secondary organism, "here are a few 
documented instances of plant pathogenicity of this bacterium, but none in 
California. In ether cases it appears to effect a certain degree of biological 
protection against primary bacterial pathogens, such as Erwinia amylovora on 
pear. There is some uncertainty regarding the possible relatedness of yellow 
pigmented plant isolates classified as £. herbicola to similar isolates of 
clinical origin. classified as Enterobacter aqqlomerans . There have been no 
reports of pathogenicity of plant Isolates to man or animals or of human 
isolates to plants. Most isolates of JE. herbicola of plant origin grow 
optimally at or near 28-30° C. and only sparsely, if at all, at 37° C. This 
supports the prevailing view that pathogenicity of yellow pigmented isolates 
classified as Erwinia herbicola or Enterobacter aagl omerans to man or warm-blooded 
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