Molecular Characterization of Citrus tatter leaf virus Historically Associated with Meyer Lemon Trees: Complete Genome Sequence and Development of Biologically Active In Vitro Transcripts

Authors

Satyanarayana Tatineni, USDA-ARSFollow
Mohammad R. Afunian, University of Florida
Mark E. Hilf, USDA-ARSFollow
Siddarame Gowda, University of Florida
William O. Dawson, University of FloridaFollow
Stephen M. Garnsey, University of Florida

Date of this Version

2009

Citation

Tatineni, S., Afunian, M. R., Hilf, M. E., Gowda, S., Dawson, W. O., and Garnsey, S. M. 2009. Molecular characterization of Citrus tatter leaf virus historically associated with Meyer lemon trees: Complete genome sequence and development of biologically active in vitro transcripts. Phytopathology 99:423-431.

Comments

U.S. government work.

Abstract

Citrus tatter leaf virus isolated from Meyer lemon trees (CTLV-ML) from California and Florida induces bud union incompatibility of citrus trees grafted on the widely used trifoliate and trifoliate hybrid rootstocks. The complete genome sequence of CTLV-ML was determined to be 6,495 nucleotides (nts), with two overlapping open reading frames (ORFs) and a poly (A) tail at the 3′ end. The genome organization is similar to other capilloviruses, with ORF1 (nts 37 to 6,354) encoding a putative 242-kDa polyprotein which contains replication-associated domains plus a coat protein (CP), and ORF2 (nts 4,788 to 5,750), which is located within ORF1 in a different reading frame and encodes a putative movement protein. Although the proteins encoded by CTLV-ML possesses 84 to 96% amino acid sequence identity with strains of Apple stem grooving virus (ASGV), we observed two strikingly different regions in ORF1: variable region I (amino acids 532 to 570) and variable region II (amino acids 1,583 to 1,868), with only 15 to 18 and 56 to 62% identities, respectively, with the corresponding regions of ASGV strains. Conditions for a herbaceous systemic assay host were optimized in which the wildtype virus induced systemic infection in Phaseolus vulgaris cv. Light Red Kidney (LRK) bean plants at 19 or 22°C but not at higher temperatures. In vitro transcripts generated from full-length cDNA clones induced systemic symptoms on LRK bean plants similar to that of the wild-type virus. Replication of the recombinant virus was confirmed by hybridization of a 5′ positive-stranded RNA-specific probe to a genome-sized RNA and by reverse-transcription polymerase chain reaction.