Item No. 1 of 1

INVESTIGATOR: Hui, A. Y.; Hui, A. Y.

PERFORMING INSTITUTION:
IOWA STATE UNIVERSITY
2229 Lincoln Way
AMES, IOWA 50011

A NOVEL FRAMESHIFT SIGNAL IN THE POTYVIRIDAE GENOME

NON-TECHNICAL SUMMARY: A third of all plant viruses are part of the Potyviridae family. These viruses cause substantial losses in a wide variety of crops such as soybean, potato, cabbage, plum and other fruits and vegetables. Generally, genetic resistance is used to minimize the impact of potyviruses in conjunction with pesticides to control the insect carriers of the virus. Both of the control methods can be overcame due to adaptation of the insects or evolution of the virus. An essential aspect of the virus life cycle needs to be targeted for effective control and to achieve this, better understanding of potyvirus molecular biology will be required. A new gene, pipo, that was recently discovered is present in all the members of Potyviridae. Previous data show that pipo expression is required for proper establishment of infection in plants. Studying the mechanism of pipo expression will provide more knowledge about potyviruses and protein translation. This may provide a new avenue of research for developing a sustainable method to control potyviruses.

OBJECTIVES: Most of the genome of potyviruses is translated as one large open reading frame (ORF) but a small overlapping ORF is conserved throughout the family. This "pretty interesting potyviral ORF" (pipo), is essential for viral infection. It is translated by a ribosomal frameshift mechanism in which viral RNA induces some ribosome to change reading frames during translation. The potyvirus Turnip mosaic virus (TuMV) will be used to identify the translational mechanism of pipo with the following specific goals. 1) Characterize the ribosomal frameshift signal in TuMV by observing ribosomal density upon the genomic RNA in conjunction with deletion mutants to determine the sequence and if any essential structural elements required for frameshifting. 2) Observe frameshift efficiency of TuMV in plants during infection. 3) Compare the frameshift signal and mechanism of TuMV to the rest of the potyvirus genus and Potyviridae family. Results will provide additional knowledge regarding the translation of plant viruses, which could lead to a novel mechanism of plant resistance. Progress will be shared at scientific conferences and in peer-reviewed publications.