VIEW ARTICLE

Depletion of the Galacturonic Acid Content in Bean Hypocotyl Cell Walls during Pathogenesis by Rhizoctonia solani and Sclerotium rolfsii. D. F. Bateman, Department of Plant Pathology, Cornell University, Ithaca, New York 14850. Phytopathology 60:1846-1847. DOI: 10.1094/Phyto-60-1846.

Cell walls prepared from infected hypocotyl tissues of 8-day-old bean (Phaseolus vulgaris ‘Red Kidney’) seedlings inoculated with Rhizoctonia solani or Sclerotium rolfsii exhibited a marked and rapid reduction in galacturonic acid content. The galacturonic acid content of cell walls prepared from diseased and healthy tissues was estimated with uronic acid dehydrogenase following enzymatic hydrolysis of cell wall samples. At the time of inoculation, cell walls from hypocotyl tissue contained about 8.3% galacturonic acid. The galacturonic acid content of cell walls from hypocotyl tissues infected with R. solani and S. rolfsii decreased to 1.7 and 1.9%, respectively, within 48 hr after inoculation, whereas cell walls prepared from comparable healthy tissues contained 6.2-7.2% galacturonic acid.