Download Virus Family: Geminiviridae

Virus Family: Geminiviridae
Category: Virus-host interactions
Title: Characterization of a recovery stage in geminivirus infected plants: Correlation
between viral DNA levels, DNA methylation and siRNA types.
Authors: E. A RODRIGUEZ-NEGRETE, J. CARRILLO-TRIPP, AND R.F. RIVERABUSTAMANTE
Address: Departamento de Ingeniería Genética, Cinvestav Irapuato, Km. 9.6
Libramiento Norte, P.O. Box 629, C.P. 36500, Irapuato, Guanajuato, México.
Abstract: Pepper golden mosaic virus (PepGMV) is an important begomovirus
distributed in Mexico and Central America in many solanaceous crops. We recently
showed that PepGMV-infected pepper plants consistently showed symptom remission,
after an initial development of the characteristic symptoms. The remission or host
recovery was correlated with a specific resistance to PepGMV found in the new
asymptomatic tissue as well as a dramatic decrease in the concentration of viral DNA
and RNA. Similarly, the presence of virus-related small interfering RNAs (siRNAs)
suggested the involvement of a post-transcriptional gene silencing (PTGS) mechanism
in the process of recovery. A further characterization of the siRNA population along the
process from the highly symptomatic leaves to the asymptomatic, newly-developed
tissue, revealed changes in the ratio of the two main types of siRNA molecules detected
(21 and 24 nt long). Interestingly, the two types of siRNA molecules seemed to be
related to different regions in the viral genome. In addition, these changes also showed
some correlation with the methylation level of viral DNA found in the different tissues
along the recovery process.