Off-campus UNL users: To download campus access dissertations, please use the following link to log into our proxy server with your NU ID and password. When you are done browsing please remember to return to this page and log out.

Non-UNL users: Please talk to your librarian about requesting this dissertation through interlibrary loan.

CODING PROPERTIES AND SEQUENCE RELATIONSHIPS AMONG RNAS OF WILD TYPE SOIL-BORNE WHEAT MOSAIC VIRUS AND ITS DELETION MUTANTS (PLANT, NUCLEIC ACID, MUTATION)

YAU-HEIU HSU, University of Nebraska - Lincoln

Abstract

Wild-type soil-borne wheat mosaic virus (SBWMV) has RNAs of 1.0L and 0.5L, designated by the relative virion lengths. Two isolates, Lab 1 of 1.0L and 0.35L, Lab 2 of 1.0L and 0.4L, were selected by repeated mechanical transfer of wild type virions. This study provides the molecular evidences for two proposed characters of SBWMV: (1) SBWMV has two RNA genomes. (2) The 0.5 RNA suffers deletion mutation to give 0.4L and 0.35L RNA. Three properties of SBWMV isolates in Nebraska were compared: (1) viral specific proteins in infected tissue, (2) peptide map of coat protein after chemical cleavage, (3) pattern of RNA deletion mutants. Lack of variation by these criteria of virus from fields shows that many wheat fields in Nebraska are infected with similar strains of SBWMV. Translations of all four RNA species in rabbit reticulocyte lysates revealed that RNA I (1.0L RNA) and RNA IIs (0.5L, 0.4L and 0.35L RNA) have different coding sequences and the coat protein gene is located on RNA IIs. The results of sequence of appearance of products, immunoprecipitation and peptide mapping demonstrate readthrough translation strategies of RNA IIs. The results also indicate that the deletion occurred near the 3' end of 0.5L RNA to give 0.4 or 0.35L RNA. Sequence relationships among the SBWMV RNAs were demonstrated by Northern hybridization. Hybridization with cDNA revealed that all three isolates have the same RNA I and that there is no homology among RNA I and RNA IIs. Homology among RNA IIs of different isolates provides further evidence for the deletion hypothesis. Terminal structures of 0.5L and 0.35L RNAs were compared. Neither RNA had poly (A) nor oligo (A) at the 3' end. Neither RNA had detectable genome-linked protein nor cap structure at the 5' end. The results indicate these two RNAs have similar terminal structures.

Subject Area

Plant pathology

Recommended Citation

HSU, YAU-HEIU, "CODING PROPERTIES AND SEQUENCE RELATIONSHIPS AMONG RNAS OF WILD TYPE SOIL-BORNE WHEAT MOSAIC VIRUS AND ITS DELETION MUTANTS (PLANT, NUCLEIC ACID, MUTATION)" (1984). ETD collection for University of Nebraska-Lincoln. AAI8428216.
https://digitalcommons.unl.edu/dissertations/AAI8428216

Share

COinS