Skip to main content
ARS Home » Research » Publications at this Location » Publication #246011
Title: Accumulation of Potato spindle tuber viroid-specific small RNAs is accompanied by specific changes in tomato gene expression

Author
item WANG, IN - Hirosaki University
item SHIBUYA, MAKOTO - Hirosaki University
item TANEDA, AKITO - Hirosaki University
item TASUKU, KURAUCHI - Hirosaki University
item SENDA, MINEO - Hirosaki University
item Owens, Robert
item SANO, TERUO - Hirosaki University

Submitted to: Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/14/2011
Publication Date: 4/27/2011
Citation: Wang, I., Shibuya, M., Taneda, A., Tasuku, K., Senda, M., Owens, R.A., Sano, T. 2011. Accumulation of Potato spindle tuber viroid-specific small RNAs is accompanied by specific changes in tomato gene expression. Virology. 413-72-83.

Interpretive Summary: Viroids are the smallest known agents of infectious disease. Diseases caused by viroids affect a large number of agriculturally-important crop plants, but the molecular mechanism(s) responsible for these diseases are still unclear. Recent evidence indicates that small RNA molecules derived from the viroid genome and acting through host RNA silencing pathways play a key role in the disease process. To better understand how viroid-specific small RNA molecules are synthesized and their possible role in disease induction, we monitored the accumulation of small, potato spindle tuber viroid (PSTVd)-specific RNAs in the leaves and stems of infected tomato plants. Large-scale sequence analysis revealed that PSTVd-specific small RNAs are actively produced from two previously unrecognized portions of its genome; furthermore, microarray analysis of changes in host gene expression profiles during infection identified several potential targets for regulation by these small RNAs. Knowing which host genes are affected by viroid infection may allow us to devise ways to block/reverse the disease process. This article is intended primarily for other research scientists working with viruses that affect plant, animal, or human hosts.

Technical Abstract: Post-transcriptional gene silencing appears to play a key role in viroid pathogenicity. To better understand the biogenesis of viroid-specific small RNAs and their possible role in disease induction, we have examined the accumulation of these small RNAs in the leaves and stems of potato spindle tuber viroid (PSTVd)-infected tomato plants using a combination of northern hybridization and deep sequencing analysis. PSTVd-specific small RNAs were more abundant in the stem tissues than in the leaves, and at least three size classes of viroid-specific small RNAs were detected. Large-scale sequence analysis revealed that PSTVd-specific small RNAs are actively produced from two newly identified regions of the genomic RNA; i.e., the upper portion of the pathogenicity and central domains. Using microarray analysis, we were able to monitor the effects of PSTVd infection on the expression level of 130 tomato genes that contain potential binding sites for PSTVd-specific small RNAs. Expression levels of 18 such genes were down-regulated early in infection. These include three genes involved in gibberellin- and systemin-mediated signaling as well as several others with additional regulatory potential.