Biosynthesis and Degradation of Storage Protein in Spores of the Fungus Botryodiplodia theobromae

Authors

Gary Petersen, University of Nebraska-Lincoln
Kurt Dahlberg, University of Nebraska-Lincoln
James L. Van Etten, University of Nebraska-LincolnFollow

Date of this Version

8-1983

Comments

Published in JOURNAL OF BACTERIOLOGY Aug. 1983, p. 601-606 m1-9193/83/08060166S02.00/0 Copyright © 1983, American Society for Microbiology. Used by permission.

Abstract

Muiridin, a spore-specific protein of the fungus Botryodiplodia theobromae, comprises about 25% of the mature pycnidiospore protein. It has an apparent molecular weight of 16,000 to 17,000 and is rich in glutamine, asparagine, and arginink. Muiridin is synthesized in developing spores via a precursor with an apparent molecular welght of 24,000. Two other polypeptides present in young developing spores with apparent molecular weights of 18,000 and 15,000 are immunologically related to muiridin. We propose a pathway for muiridin synthesis. Muiridin is actively degraded during the germination of spores from 30-day old cultures. This degradation is independent of exogenous amino acids in the germination medium. In contrast, glutamine and, to a lesser extent, asparagine partially inhibit the degradation of muiridin during germination of spores from 7- day-old cultures.