Identification and Partial Characterization of Endogenous Double-stranded Ribonucleic Acid in Mulberry

Abstract

Double-stranded ribonucleic acid (dsRNA) analysis of apparently healthy red mulberry (Morus rubra L.) yielded four distinct dsRNA banding profiles. dsRNA type 1 contained three dsRNA bands with approximate molecular weights (MWs) of 12.0, 1.0, and 0.9 × 106, respectively. dsRNA type 2 contained two dsRNA bands with MWs of 1.0 and 0.9 × 106. dsRNA type 3 contained four dsRNA bands with MWs of 1.0, 0.9, 0.89, and 0.88 × 106. dsRNA type 4 contained three dsRNA bands with MWs of 1.0, 0.88, and 0.87 × 106. No virus particles were associated with any of the samples analyzed. All four types of dsRNA were resistant to DNase I and RNase A in high salt and susceptible to RNase A in low salt. Mulberry dsRNAs were somewhat similar to endogenous dsRNAs (edsRNA) associated with other hosts. This is the first report of edsRNA associated with a deciduous tree.