Articles
PROPERTIES OF APPLE STEM GROOVING AND APPLE CHLOROTIC LEAF SPOT VIRUSES
They are associated with apple topworking disease in Japan.
In the present study, we compared the properties of the nucleic acids and proteins of Japanese isolates of ASGV and ACLSV and the dsRNA species found in ASGV- and ACLSV-infected plants.
We also produced complementary DNA (cDNA) clones to ACLSV-RNA and used them as probes for detection of ACLSV-RNA from plants.
The particles of ASGV contained a single coat protein species with a mol. wt. of 27000 and a single RNA species of 2.30 x 106. The corresponding values for particles of ACLSV were 22000 and 2.48 x 106, respectively.
RNAs of both ASGV and ACLSV were single- stranded, polyadenylated and plus-sense.
Preparations of dsRNA from ASGV-infected plant leaves contained four virus-specific species [mol. wt. ( x 10-6) 4.8, 4.3, 3.9 and 3.5], whereas three major [mol. wt. ( x 10-6) 4.9, 4.3 and 3.9] and two minor (4.5 and 3.1) virus-specific dsRNAs were found in ACLSV-infected plants.
cDNA of ACLSV-RNA was synthesized using oligo (dT) and randam primer, and was subsequently cloned into the Pst I site of the pUC9 plasmid of the Escherichia coli. The resulting cloned fragments ranged from 0.4 to 4.2 kbp.
Restriction mapping showed that they collectively represented more than 90 % of the ACLSV genome.
Dotblot hybidization using biotin-labeled cDNA clones as probes allowed the detection at a minimum concentration of 1.6 ng of purified virus and 25.6 pg of viral RNA. By this method, ACLSV could be successfully detected from infected Chenopodium quinoa.