Analysis of small RNA production patterns among the two potato spindle tuber viroid variants in tomato plants

In order to analyze the production of small RNA (sRNA) by viroids upon infecting the plants, the tomato plants (Solanum lycopersicum cultivar Rutgers) were inoculated with the variants of Potato spindle tuber viroid (PSTVd). After 21-days of postinoculation, total RNA was extracted and subjected for deep-sequencing using Illumina HiSeq platform. The primers were trimmed and only 21- to 24-nt long sRNAs were filtered after quality check of the raw data. The filtered sRNA population was then mapped against both the genomic (+) and antigenomic (−) strands of the respective PSTVd variants using standard pattern-matching algorithm. The profiling of viroid derived sRNA (vd-sRNA) revealed that the viroids are susceptible to host RNA silencing mechanism. High-throughput sequence data linked to this project have been deposited in the Gene Expression Omnibus (GEO) database under accession number GSE69225.