Complete Deletion of Wheat Streak Mosaic Virus HC-Pro: a Null Mutant Is Viable for Systemic Infection

Authors

Drake C. Stenger, United States Department of Agriculture—Agricultural Research ServiceFollow
Roy C. French, University of Nebraska-LincolnFollow
Frederick E. Gildow, Pennsylvania State University, University Park, Pennsylvania

Date of this Version

September 2005

Comments

Published in JOURNAL OF VIROLOGY, Sept. 2005, p. 12077–12080.

Abstract

A Wheat streak mosaic virus (WSMV) genome lacking HC-Pro was constructed and confirmed by reverse transcription-PCR to systemically infect wheat, oat, and corn. Coupled in vitro transcription/translation reactions indicated that WSMV P1 proteinase cleaved the polyprotein at the P1/P3 junction of the HC-Pro null mutant. The WSMV HC-Pro null mutant was competent for virion formation, but the virus titer was reduced 4.5-fold relative to that of the wild type. Collectively, these results indicate that WSMV HC-Pro is dispensable for replication and movement, two essential processes that are disrupted by point and small-insertion mutations introduced into potyvirus HC-Pro.