HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Mohamed, N. A. Articles by Symons, R. H. Search for Related Content PubMed Articles by Mohamed, N. A. Articles by Symons, R. H. Agricola Articles by Mohamed, N. A. Articles by Symons, R. H.

Characterization of the Different Electrophoretic Forms of the Cadang-Cadang Viroid

N. A. Mohamed^1,

¹ FAO/UNDP Coconut Project, Philippine Coconut Authority, Albay Research Center, Guinobatan, Albay, Philippines 4908
and² Adelaide Centre for Gene Technology, Department of Biochemistry, University of Adelaide, Adelaide, South Australia 5001

The relationship between symptom development and changes in the fast and slow electrophoretic forms of the two cadang-cadang disease-associated RNAs (ccRNA-1 and ccRNA-2) has been examined. The fast form of each is present in trees for up to 2 years before the appearance of symptoms, indicating an incubation period of about 2 years. Trees showing the first symptoms (on the nuts) contain only the fast form of the ccRNAs; the development of leaf symptoms coincides with the first detection of the slow form. After this time, both slow and fast forms are found in the newly developing fronds for the next 9 to 12 months but then, as symptoms develop, new fronds contain only the slow form. Therefore, at later stages of disease, only the slow form can be detected in all fronds. The fast form of ccRNA-1 and/or ccRNA-2 therefore appears to be the infectious form in nature. The number of nucleotides in the four ccRNAs as determined by polyacrylamide gel electrophoresis under denaturing conditions are: ccRNA-1 fast, 250; ccRNA-1 slow, 300; ccRNA-2 fast, 500; ccRNA-2 slow, 600. On the basis of two-dimensional fingerprints of ribonuclease A and T₁ digests of the four ccRNAs, it was concluded that the ccRNAs are composed of repeated sequences of ccRNA-1 fast, and each of the ccRNA-2 forms is a dimer of the respective ccRNA-1 form.

Keywords: cadang-cadang, viroids, RNA dimers, disease symptoms

Present address: National Institute of Health, P.O. Box 50348, Porirua, New Zealand.

Received 10 March 1982; accepted 8 June 1982.

This article has been cited by other articles:

				R. Sanjuan, J. Forment, and S. F. Elena In Silico Predicted Robustness of Viroids RNA Secondary Structures. I. The Effect of Single Mutations Mol. Biol. Evol., July 1, 2006; 23(7): 1427 - 1436. [Abstract] [Full Text] [PDF]