Location: Molecular Plant Pathology LaboratoryTitle: Complete nucleotide sequence of Hibiscus infecting Cilevirus Florida isolate and its relationship with closely associated Cileviruses Author
|Stone, Andrew - Andy|
Submitted to: Genome Announcements
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/15/2017
Publication Date: 1/25/2018
Citation: Roy, A., Stone, A.L., Melzer, M.J., Hartung, J.S., Shao, J.Y., Mavrodieva, V., Nakhla, M.K., Brlansky, R.H., Schneider, W.L. 2018. Complete nucleotide sequence of Hibiscus infecting Cilevirus Florida isolate and its relationship with closely associated Cileviruses. Genome Announcements. Genome Announcements. 6(4):e01521-17. Interpretive Summary: Unexpected symptoms were recently observed on hibiscus plants in Tampa, Florida. The green ringspot symptoms were strikingly similar to those observed previously on hibiscus in Hawaii. The symptoms in Hawaii were shown to be due to infection by new a virus named Hibiscus-infecting Cilevirus. Initial testing showed that the symptoms on the hibiscus plants in Florida were indeed caused by a virus that is very similar to the virus reported in Hawaii. Members of this group of viruses are known to cause very serious diseases of citrus in South America. For this reason, the full genome of the new virus from Florida was obtained and is the subject of this report. The new virus is very closely related to both the hibisicus-infecting Cilevirus from Hawaii and a citrus-infecting strain from Colombia. The virus in Colombia causes a very serious disease of citrus. This group of viruses is transmitted by a group of mites that is very common in Florida. Research is needed to determine if the mites present in Florida are able to transmit this virus to citrus. The complete sequence data has also enabled the development of diagnostic tests that are specific for this virus.
Technical Abstract: The complete nucleotide sequence of a recently discovered Florida (FL) isolate of Hibiscus infecting Cilevirus (HiCV) was determined by Sanger sequencing. The movement- and coat- protein gene sequences of the HiCV-FL isolate are more divergent than other genes of the previously sequenced HiCV-HA (Hawaii) isolate. The complete genome of the HiCV-FL isolate is 13,718 nucleotides (nt) in length. The genome is composed of RNA1 and RNA2 of 8,727 and 4,991 nt, respectively, including the poly(A) tails at the 3'-terminus. RNA1 of HiCV-FL has two ORFs. ORF1 of RNA1 encodes a large polyprotein (p285) with methyl-transferase, protease, helicase, RNA dependant RNA polymerase domains that share 95-98% amino acid (aa) with CiLV-C2 (JX000024) and HiCV-HA (KC626783), respectively. ORF2 encodes a putative coat protein gene (p29) which is distinct and shares only 92-93% aa sequence identity with HiCV-HA and CiLV-C2. RNA2 is organized into five ORFs that encode 4 hypothetical proteins and one movement protein (MP) in the order of 5'-p15-p9-p61-MP-p24-3'. ORF2 of RNA2 is 243 nt in length, longer than observed in HiCV-HA (195 nt) or CiLV-C2 (204 nt) genome sequences. Three other hypothetical proteins; p15, p61 and p24 of HiCV-FL-RNA2 share 94-99% nt and 98-100% aa sequence identity with HiCV-HA. Research is needed to determine if the mite vectors active on hibiscus in Florida are capable of reproduction on citrus, and thereby transmission of this virus to citrus.