First report of Tomato aspermy virus in Chrysanthemum zawadskii var. latilobum in Korea

Authors: KWAK, H.-R - Korean Rural Development Administration; KIM, J - Chungcheongnam-Do Agricultural Research And Extension Services; KIM, J.-E - Chungbuk National University; BYUN, H.-S - Korean Rural Development Administration; CHOI, H.-S - Korean Rural Development Administration; Wintermantel, William - Bill; KIM, MIKYEONG - Chungbuk National University

Submitted to: Journal of Plant Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/26/2021
Publication Date: 4/14/2021
Citation: Kwak, H.-R., Kim, J.-G., Kim, J.-E., Byun, H.-S., Choi, H.-S., Wintermantel, W.M., Kim, M. 2021. First report of Tomato aspermy virus in Chrysanthemum zawadskii var. latilobum in Korea. Journal of Plant Pathology. https://doi.org/10.1007/s42161-021-00797-2.
DOI: https://doi.org/10.1007/s42161-021-00797-2

Interpretive Summary: Chrysanthemum zawadskii var. latilobum (Cz) has been used as a tea and a traditional folk medicine to treat various human diseases in Asia. In September 2017, disease symptoms consisting of bright yellow blotches and jagged edged markings were observed on leaves of Cz plants in Yesan-gun, South Korea. We identified Tomato aspermy virus (TAV) in these plants. TAV has been reported to infect tomato, chrysanthemum, gladiolus, and pepper worldwide. The TAV-Cz isolate is most closely related to the tomato and chrysanthemum isolates G1, H9, Go34 from Japan, a petunia isolate from Iran, and TAV-KC isolated from Chrysanthemum sp. in Korea. The genomes of TAV-V, TAV-1 and India isolates contain an insert of approximately 165 nucleotides that was not present in TAV-Cz. This is the first report of TAV on Chrysanthemum zawadskii var. latilobum) to our knowledge. Cz is cultivated through vegetative reproduction for herbal remedies and local flower festivals in Korea. Cz propagators are advised to use virus-free saplings in order to prevent the spread of the virus.

Technical Abstract: Tomato aspermy virus (TAV), belongs to the genus Cucumovirus in the family Bromoviridae and has been reported to infect tomato, chrysanthemum, gladiolus, and pepper worldwide (Inoue et al. 2018; Procter 1975; Raj et al. 2011). Chrysanthemum zawadskii var. latilobum (Cz) has been used as a tea and a traditional folk medicine to treat various human diseases in Asia. In September 2017, disease symptoms consisting of bright yellow blotches and jagged edged markings were observed on leaves of Cz plant in Yesan-gun, South Korea. To identify viruses that infect Cz, total RNA was extracted from leaves of a Cz sample using the Plant RNA Prep Kit (Biocubesystem, Korea) and tested by RT-PCR using primers specific for the TAV coat protein gene. A 971 bp product of the expected amplicon size was obtained from the Cz sample, and was cloned and sequenced. The complete CP gene sequence of the TAV isolate from Cz was deposited in GenBank (MT407570). BLASTn analysis of the TAV-Cz isolate revealed highest (99.7%) identity with TAV-V and -P isolates (L15335, L79972) and 99.39% identity with KC-TAV (AJ237849, chrysanthemum, South Korea). Cz samples were negative by RT-PCR analyses for six other viruses known to infect Chrysanthemum spp. in Korea: cucumber mosaic virus, carnation Italian ringspot virus, chrysanthemum stunt viroid, chrysanthemum stem necrosis virus, chrysanthemum virus B, and tomato spotted wilt virus. Nicotiana benthamiana and N. glutinosa plants sap inoculated with extracts from symptomatic Cz tissues infected with the TAV-Cz isolate exhibited mosaic symptoms and tested positive for TAV by RT-PCR. The complete RNA 3 of TAV-Cz was then sequenced and is comprised of 2,222 nucleotides, and like other TAV isolates, encodes the 3a protein and CP gene. A phylogenetic tree based on RNA 3 of TAV-Cz and 18 other TAV isolates was constructed using MEGA-X with CMV as an outgroup. TAV-Cz isolate is most closely related to the tomato and chrysanthemum isolates G1, H9, Go34 from Japan, a petunia isolate from Iran, and TAV-KC isolated from Chrysanthemum sp. in Korea. The genomes of TAV-V, TAV-1 and India isolates contain an insert of 163~166 nucleotides at the 3’ untranslated region of RNA 3 that is not present in TAV-Cz. This is the first report to our knowledge of TAV on Chrysanthemum zawadskii var. latilobum). Virus-free saplings should be used to prevent the spread of the virus, as Cz is cultivated through vegetative reproduction for herbal remedies and local flower festivals in Korea.