RT Journal Article SR Electronic(1) A1 Mohamed, N. A. A1 Thomas, WayneYR 1980 T1 Viroid-like Properties of an RNA Species Associated with the Sunblotch Disease of Avocados JF Journal of General Virology, VO 46 IS 1 SP 157 OP 167 DO https://doi.org/10.1099/0022-1317-46-1-157 PB Microbiology Society, SN 1465-2099, AB SUMMARY A low mol. wt. RNA species is associated with sunblotch disease of avocados. The RNA (SB-RNA) was recovered from leaves and bark of symptomless carrier trees and from bark lesions of symptom-bearing trees. It was not detected in leaves or bark from lesion-free areas of symptom-bearing trees or in leaf or bark from healthy trees. SB-RNA is soluble in LiCl and migrates in 20% polyacrylamide gels. In high salt buffers, it is resistant to ribonuclease A at a concentration of 1 µg/ml and is degraded only slowly at 10 µg/ml. The RNA is less resistant to ribonuclease A at low salt concentrations (0.01 m). The mobility of the SB-RNA in polyacrylamide gels is not affected by heat denaturation. The apparent mol. wt. of native SB-RNA is 65000 whilst under denaturing conditions it is 112000 to 115000. SB-RNA occurs in high concentration in leaves of symptomless carrier trees being detected in 1 g of fresh leaf. In tissue fractionation experiments, SB-RNA was associated mainly with the chloroplast and endoplasmic reticulum fractions. It is concluded from these properties of SB-RNA that sunblotch is a viroid disease., UL https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-46-1-157