Small RNA Profiling of Cucurbit Yellow Stunting Disorder Virus from Susceptible and Tolerant Squash (Cucurbita pepo) Lines

Saritha Raman Kavalappara; Sudeep Bag; Alex Luckew; Cecilia E McGregor

doi:10.3390/v15030788

Small RNA Profiling of Cucurbit Yellow Stunting Disorder Virus from Susceptible and Tolerant Squash (Cucurbita pepo) Lines

Viruses. 2023 Mar 19;15(3):788. doi: 10.3390/v15030788.

Authors

Saritha Raman Kavalappara¹, Sudeep Bag¹, Alex Luckew², Cecilia E McGregor²

Affiliations

¹ Department of Plant Pathology, University of Georgia, Tifton, GA 31793, USA.
² Department of Horticulture, University of Georgia, Athens, GA 30602, USA.

Abstract

RNA silencing is a crucial mechanism of the antiviral immunity system in plants. Small RNAs guide Argonaut proteins to target viral RNA or DNA, preventing virus accumulation. Small RNA profiles in Cucurbita pepo line PI 420328 with tolerance to cucurbit yellow stunting disorder virus (CYSDV) were compared with those in Gold Star, a susceptible cultivar. The lower CYSDV symptom severity in PI 420328 correlated with lower virus titers and fewer sRNAs derived from CYSDV (vsRNA) compared to Gold Star. Elevated levels of 21- and 22-nucleotide (nt) size class vsRNAs were observed in PI 420328, indicating more robust and efficient RNA silencing in PI 420328. The distribution of vsRNA hotspots along the CYSDV genome was similar in both PI 420328 and Gold Star. However, the 3' UTRs, CPm, and p26 were targeted at a higher frequency in PI 420328.

Keywords: Cucurbita pepo; crinivirus; cucurbit yellow stunting disorder virus; tolerance; virus-derived small RNA.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Crinivirus* / genetics
Cucurbita* / genetics
RNA Interference
RNA, Viral / genetics

Substances

RNA, Viral

Supplementary concepts

Cucurbit yellow stunting disOrder virus

Grants and funding

This study was supported by the USDA-UGA Cooperative Agreement, project number 58-6080-9-006. S.B. is supported by the USDA-National Institute of Food and Agriculture-HATCH project (Accession No. 1020319). The funders had no role in the study design, data collection and analysis, publishing decision, or manuscript preparation.