| Description: | The continuing escalation of disease and resistance has led to the development defense strategies by the host and counter- strategies by the pathogen. Inhibition of the host?s programmed cell death response is one counter-strategy exhibited by some animal viruses. To our knowledge Turnip crinkle virus (TCV) is the first plant virus which appears to share this ability. Resistant Arabidopsis Di-17 plants respond to TCV inoculation with the necrotic lesions of a classic hypersensitive response (HR), increases in salicylic acid and defense gene transcription. The virus is predominantly localized to the lesions of the HR. However, in a fraction of the plants, which can vary from 5-50% depending on growth conditions, the virus escapes the lesions. In these plants, the virus spreads to newly emerging portions of the plant, causing disease symptoms similar to those exhibited by TCV- infected, susceptible plants. Strikingly, these systemically infected portions of the plant do not exhibit the HR, though they contain the viral elicitor of the defense response. Further, systemically infected leaves will not produce a HR if directly reinoculated, though leaves of equivalent age on a disease-free inoculated plant will. However, asymptomatic leaves of a systemically infected plant contain little, if any, virus, and do evolve a HR upon direct reinoculation. Thus, the suppression of the HR appears to correlate with the presence of viral RNA. Significantly, recent literature shows that one of the TCV movement proteins, p8, is nuclearly localized. This protein has a high affinity for RNA and also binds DNA. Thus this protein may be altering gene expression patterns. We would like to use the microarray technology to discern differences in gene expression between symptomatic and asymptomatic plants. Di-17 plants will be inoculated with viral RNA. After disease symptoms become apparent, symptomatic leaves and the developmentally equivalent leaves on asymptomatic plants will be inoculated with virus. Tissue will be harvested 3 days post reinoculation, once lesions become apparent on the resisting plants. The reinoculation protocol is designed to compensate for the observed elevation in defense gene expresion in symptomatic leaves relative to uninoculated asymptomatic leaves. It is anticipated that this experiment will provide insight into virally induced differences in gene expression leading to suppression of the HR. |
NASCArrays Information at The BAR
Welcome to NASCArrays information at the BAR. This page hosts meta-information from the NASCArrays service (2002-2013). This information was parsed
from text files available on the NASCArrays site. NASCArrays data is on iPlant server. To download experiment data from iPlant, please click on the
experiment number. To download the CEL files, please click on the ftp link.