VIEW ARTICLE

Physiology and Biochemistry

Evidence for a Factor that Stimulates Tissue Maceration by Pectolytic Enzymes. Shigetaka Ishii, Senior Research Scientist, Central Research Laboratories, Kikkoman Shoyu Co., Ltd., 399 Noda, Noda-shi, Chiba-ken 278 Japan; Keiichi Kiho, Research Scientist, Central Research Laboratories, Kikkoman Shoyu Co., Ltd., 399 Noda, Noda-shi, Chiba-ken 278 Japan. Phytopathology 66:1077-1081. Accepted for Publication 4 March 1976. Copyright © 1976 The American Phytopathological Society, 3340 Pilot Knob Road, St. Paul, MN 55121. All rights reserved.. DOI: 10.1094/Phyto-66-1077.

A factor that stimulates tissue maceration by pectolytic enzymes was isolated from the culture medium of Aspergillus japonicus by DEAE-Sephadex column chromatography and isoelectric focusing. The factor alone could not macerate plant tissues but it greatly stimulate the maceration of potato, onion, and radish tissues both by endo-pectin lyase and by endo-polygalacturonase. The stimulating factor was a heat-labile, high-molecular-weight substance, which suggested that it may be an enzyme. It showed little or no ability to degrade pectin, pectic acid, arabinan, galactan, arabinogalactan, xylan, and protein. Only low cellulase activity was detected in the final preparation of the stimulating factor. However, there was a remarkable difference in heat stability between this factor and cellulase.