VIEW ARTICLE

Physiology and Biochemistry

Effects of Purified Cutin Esterase Upon the Permeability and Mechanical Strength of Cutin Membranes. C. Jacyn Baker, Department of Plant Pathology, Cornell University, Ithaca, NY 14853, Present address: U.S. Department of Agriculture, Applied Plant Pathology Laboratory, Beltsville, MD 20705; Susan L. McCormick(2), and Durward F. Bateman(3). (2)Department of Plant Pathology, Cornell University, Ithaca, NY 14853; Present address: Department of Zoology, University of Georgia, Athens 30602, (3)Department of Plant Pathology, Cornell University, Ithaca, NY 14853, Present address: North Carolina Agricultural Research Service, North Carolina State University, Raleigh 27650. Phytopathology 72:420-423. Accepted for publication 6 July 1981. Copyright 1982 The American Phytopathological Society. DOI: 10.1094/Phyto-72-420.

Cutin esterase was purified from 5-day-old cultures of Fusarium solani f. sp. pisi grown on V-8 juice medium supplemented with 0.5% apple cutin. Cutin membranes were prepared from skins of grape berries by dewaxing in organic solvents followed by treatment with pectinase and cellulase. Intact cutin membranes in the absence of cutin esterase failed to permit the passage of glucose-U-¹⁴C between the cells of a double cell diffusion apparatus, whereas in the presence of 3–4 units of cutin esterase (1 unit of enzyme at 25 C hydrolyzed 1 μmole of p-nitrophenyl acetate per min at pH 8.5), glucose as well as cutin esterase readily traversed the cutin membranes. Cutin membranes exposed to cutin esterase for 72 hr permitted the passage of three enzymes that degrade cell walls: β-1,4-xylanase (mol wt 15,000), endo-α-1,4-pectate lyase (mol wt 30,000), and α-l-arabinofuranosidase (mol wt 60,000); such membranes were ruptured by a hydrostatic pressure of 0–15 cm, whereas control membranes were ruptured by a hydrostatic pressure of 48–107 cm.