New Insights in Plant Response to Viroid Infection by Differential Expression Analysis

Abstract

Viroids are small circular RNA molecules, 246 to 400 nt long, which infect several crop plants and can cause diseases of economic importance. Citrus spp. are the hosts in which the highest number of viroids has been recovered. Citrus exocortis viroid (CEVd), causal agent of citrus exocortis disease, is responsible for several losses in citrus crops. Little is known about the molecular and cellular mechanisms by which viroids infect plants and produce symptoms. To deepen this knowledge, changes in the gene-expression profile during the early (pre–symptomatic) and the last (post-symptomatic) stage of Etrog citron infection by Citrus exocortis viroid (CEVd) were investigated using a citrus cDNA microarray. MaSigPro analysis was performed, and based on their expression profile along time, genes were divided into five clusters. These results will allow us to have a clearer idea about the changes in the plant transcriptome that are associated with symptom expression and/or with specific plant defense mechanisms.