VIEW ARTICLE

Some Physiological Effects of Agrobacterium Rhizogenes on Tomato. D. Huisingh, Associate Professor, Department of Plant Pathology, North Carolina State University, Raleigh 27607; R. D. Durbin, Leader, Pioneering Research Laboratory, Crops Research Division, ARS, USDA, Department of Plant Pathology, University of Wisconsin, Madison 53706. Phytopathology 60:1101-1105. Accepted for publication 24 February 1970. DOI: 10.1094/Phyto-60-1101.

Physiological studies using tomatoes infected with Agrobacterium rhizogenes revealed that wet wt., soluble protein, ascorbic acid oxidase activity, and indole-3-acetic acid (IAA) concn increased about 100% while peroxidase activity increased as much as 1,000 to 1,200% over that in wounded-control plants by 15 days after inoculation and wounding, respectively. The peroxidatic activity was electro-phoretically separable into several discrete isozymes, with two new ones appearing only in extracts from diseased tissues. One of the new isozymes appeared to oxidize IAA. Susceptibility to inhibition by chlorogenic acid and the low pH optimum attest further to the presence of IAA oxidation by a peroxidase in the diseased tomatoes.