Submitted to: Plant and Animal Genome Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 10/20/2004
Publication Date: 1/20/2005
Citation: Mangwende, T., Mirkov, E., Albert, H.H. 2005. The P0 protein of sugarcane yellow leaf virus is a suppressor of posttranscriptional gene silencing. Plant and Animal Genome Conference XIII Proceedings. Abstract A161, P38. Interpretive Summary: problem: Many viruses have proteins which act to suppress the plants anti-viral posttranscriptional gene silencing (PTGS); does sugarcane yellow leaf virus (SCYLV) have such a suppressor? who did work: A collaborative project between ARS, Hawaii Agriculture Research Center (HARC), and Texas A&M Agricultural Experiment Station. result: It was shown that the P0 protein of SCYLV acts to suppress local and systemic PTGS induced by expression of a sense transgene, but does not block PTGS induced by a double-strand RNA producing transgene. impact: This advances basic knowledge of plant virus defenses/ virus counter-defenses, and PTGS as a means of controlling gene expression. A possible long-term impact would be the development of technologies to prevent PTGS of transgenes without impairing regulation of endogenous genes.
Technical Abstract: Sugarcane yellow leaf virus (SCYLV), the causative agent of the yellow leaf syndrome is a member of the family luteoviridae. Although SCYLV is not yet classified as either a polero-, luteo-, or enamo- virus, its genome organization closely resembles that of poleroviruses. SCYLV has six major ORFs, all encoding proteins that are significantly similar to those of known functions in poleroviruses except for the ORF0. The SCYLV ORF0 encodes a 30 kDa protein containing a predicted transmembrane domain in the N-terminus. The P0 protein has no known function in SCYLV and shows little amino acid similarity to the P0 protein of poleroviruses, which are themselves highly diverse. In the poleroviruses (PLRV, BWYV and CABYV) P0 affects virus accumulation and is also a suppressor of posttranscriptional gene silencing (PTGS). Using agroinfiltration of Nicotiana benthamiana with GFP reporter constructs, P0, and previously characterized viral suppressors of PTGS, we show that P0 of SCYLV is a suppressor of PTGS and that the suppressing activity is reduced when the transmembrane domain is deleted.