Submitted to: Oklahoma Academy of Science Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: December 6, 1996
Publication Date: N/A
Peroxidase is a plant enzyme that has been implicated in wound healing lignification, suberization, and antifungal activity. Peroxidase activity was low in fruit harvested 10 and 15 days after anthesis (DAA), regardless of tissue type. In fruit harvested 20 and 30 DAA, peroxidase levels increased in the exocarp and peaked in fruit harvested 30-40 DAA. Peroxidase isozymes in the exocarp also increased from one faint peroxidas band (ca. pI 6.0) in fruit harvested 10 DAA to at least 3 peroxidase bands ranging from pI 3.0 to 9.0 in fruit harvested 20-30 DAA. The pI 6.0 peroxidase exocarp isozyme increased in intensity in fruit harvested 20 DAA and decreased in fruit harvested 40 and 50 DAA. Nitrocellulose tissue blots indicated that peroxidase activity was primarily located in the exocarp tissue as the fruit ripened. peroxidase activity in the exocarp increased during net development according to total peroxidase activity, isozyme patterns, and nitrocellulose tissue blots. The role of peroxidase in cantaloupe ripening, net development, and disease resistance is unknown, but the increase of peroxidase in fruit harvested 15-20 DAA corresponds to net development and the decrease of the pI 6.0 isozyme in fruit harvested 40-50 DAA corresponds to the induction of latent fungal pathogens.