First Report of Tomato chlorosis virus Infecting Tomato in Georgia

Abstract

Tomato yellow leaf curl virus (TYLCV) and Tomato spotted wilt virus (TSWV) are prevalent in field-grown tomato (Solanum lycopersicum) production in Georgia. Typical TYLCV symptoms were observed during varietal trials in fall 2009 and 2010 to screen genotypes against TYLCV at the Coastal Plain Experiment Station, Tifton, GA. However, foliar symptoms atypical of TYLCV including interveinal chlorosis, purpling, brittleness, and mottling on upper and middle leaves and bronzing and intense interveinal chlorosis on lower leaves were also observed. Heavy whitefly (Bemisia tabaci (Gennadius), B biotype) infestation was also observed on all tomato genotypes. Preliminary tests (PCR and nucleic acid hybridization) in fall 2009 indicated the presence of TYLCV, TSWV, Cucumber mosaic virus, and Tomato chlorosis virus (ToCV); all with the exception of ToCV have been reported in Georgia. Sixteen additional symptomatic leaf samples were randomly collected in fall 2010 and the preliminary results from 2009 were used to guide testing. DNA and RNA were individually extracted using commercially available kits and used for PCR testing for ToCV, TYLCV, and TSWV. Reverse transcription (RT)-PCR with ToCV CP gene specific primers (4) produced approximately 750-bp amplicons from nine of the 16 leaf samples. Four of the nine CP gene amplicons were purified and directly sequenced in both directions. The sequences were 99.4 to 100.0% identical with each other (GenBank Accession Nos. HQ879840 to HQ879843). They were 99.3 to 99.5%, 97.2 to 97.5%, and 98.6 to 98.9% identical to ToCV CP sequences from Florida (Accession No. AY903448), Spain (Accession No. DQ136146), and Greece (Accession No. EU284744), respectively. The presence of ToCV was confirmed by amplifying a portion of the HSP70h gene using the primers HSP-1F and HSP-1R (1). RT-PCR produced approximately 900-bp amplicons in the same nine samples. Four HSP70h gene amplicons were purified and directly sequenced in both directions. The sequences were 99.4 to 99.7% identical to each other (Accession Nos. HQ879844 to HQ879847). They were 99.2 to 99.5%, 98.0 to 98.4%, and 98.9 to 99.3% identical to HSP70h sequences from Florida (Accession No. AY903448), Spain (Accession No. DQ136146), and Greece (Accession No. EU284744), respectively. TYLCV was also detected in all 16 samples by PCR using degenerate begomovirus primers PAL1v 1978 and PARIc 496 (3) followed by sequencing. TSWV was also detected in two of the ToCVinfected samples by RT-PCR with TSWV N gene specific primers (2) followed by sequencing. To our knowledge, this is the first report of the natural occurrence of ToCV in Georgia. Further studies are required to quantify the yield losses from ToCV alone and synergistic interactions between ToCV in combination with TSWV and/or TYLCV in tomato production in Georgia. References: (1) T. Hirota et al. J. Gen. Plant Pathol. 76:168, 2010. (2) R. K. Jain et al. Plant Dis. 82:900, 1998. (3) M. R. Rojas et al. Plant Dis. 77:340, 1993. (4) L. Segev et al. Plant Dis. 88:1160, 2004.

Discovery of Novel Chromone Derivatives Containing a Sulfonamide Moiety as Anti-ToCV Agents through the Tomato Chlorosis Virus Coat Protein-Oriented Screening Method

“…ToCV was first reported in the United States in 1998 . In the past 22 years, the virus had swept through many countries and regions in Europe, America, and Asia at an accelerating speed, causing great losses to the vegetable industry. − Given that ToCV is transmitted by whiteflies, insecticides are generally used to control their vectors to inhibit ToCV. However, the control effect is poor.…”

Discovery of Potent and Novel Quinazolinone Sulfide Inhibitors with Anti-ToCV Activity

“…In 1998, a new virus named ToCV was brought to light in tomatoes growing in greenhouses in Columbia, Baker, Florida, Colorado, and other cities . This virus has swept across dozens of countries, such as China, the United States, Brazil, and France, at an amazing pace during the following two decades. − From the bottom up, the tomato will show some symptoms similar to malnutrition once it is infected with ToCV. The main manifestation is that the leaves gradually become fragile, the mature leaves at the bottom of the tomatoes become slightly greenish, and the middle and above leaves become yellow and green .…”

Phylogenetic Characterization of Tomato chlorosis virus Population in Korea: Evidence of Reassortment between Isolates from Different Origins

“…The chlorotic leaf symptom of tomatoes was observed in Florida in 1989, and the virus responsible was first named Tomato chlorosis virus (ToCV) in the USA ( Wisler et al, 1998b ). Subsequently, this virus has been distributed to many parts of the world including European, American, African and Asian countries ( Abou-Jawdah et al, 2006 ; Accotto et al, 2001 ; Alvarez-Ruiz et al, 2007 ; Arruabarrena et al, 2015 ; Barbosa et al, 2008 ; Bese et al, 2011 ; Castro et al, 2009 ; Çevik and Erkıß, 2008 ; Dalmon et al, 2005 ; Dovas et al, 2002 ; Fiallo-Olivé et al, 2011 ; Hirota et al, 2010 ; Jacquemond et al, 2009 ; Lett et al, 2009 ; Louro et al, 2000 ; Segev et al, 2004 ; Sundaraj et al, 2011 ; Wintermantel et al, 2001 ; Wintermantel and Wisler, 2006 ; Zhao et al, 2013a ). In northeast Asia, ToCV occurrence was originally reported in China, Taiwan and Japan ( Hirota et al, 2010 ; Tsai et al, 2004 ; Zhao et al, 2013b ), but was not reported in Korea until 2013.…”