The Research On Apple Purification And Fungi Inhibition

Plant polygalacturonase inhibiting protein can deactivate the endo-polygalacturonase of fungi, decrease the infection ability of plant disease. Aimed at the antimicrobial mechanism and the inhibiting effect of PGIP, apple PGIP protein from apple cortical tissue was purified and the inhibiting effect was analyzed.With the material of apple cortical tissue, an PGIP was purified by the following steps, NaCl buffer extraction, 35%-75% ammonium sulfate precipitation, ion exchange chromatography on CM-Sephadex C-50, and then gel filtration on Sephadex G-100. The molecular weight of purified product was measured and the anti-activity to fungi was tested. Detailed results were as follows:1. Set up a method for purifying PGIP from apple cortical tissue.The yield of purified PGIP was 0.7 mg from 2000 g apple cortical tissue by the following steps: NaCl buffer extraction, 35%-75% ammonium sulfate precipitation, NaCl buffer dialysis, PEG-6000 concentration, ion exchange chromatography on CM-Sephadex C-50, and then gel filtration on Sephadex G-100.2. The first of showed PGIP inhibit the PG and the activity from Monilinia fructigena by experiment.The PG from Monilinia fructigena were inhibited by PGIP and its growth was delayed by PGIP. The hypha of Monilinia fructigena was thin and weak. Monilinia fructigena was wavy because of touching PGIP.The inhibiting effect to other fungus was in process.