Genome Sequence of Euphorbia mosaic virus from Passionfruit and Euphorbia heterophylla in Florida.

Euphorbia mosaic virus (EuMV) was found in a symptomatic passionfruit (Passiflora edulis) plant from Homestead, Florida, USA, as well as in the symptomatic weed Euphorbia heterophylla This is the first identification of EuMV in Florida and the United States and the first report of a natural infection of passionfruit by EuMV.

GENOME ANNOUNCEMENT

Euphorbia mosaic virus (EuMV) is a species of Begomovirus (Geminiviridae), a taxon of plant viruses characterized by single-stranded circular DNA genomes (1). EuMV has a bipartite genome consisting of a DNA-A (2,609 to 2,615 nucleotides [nt]) and a DNA-B (2,571 to 2,590 nt).

DNA was extracted from the leaves of a passionfruit plant (Passiflora edulis Sims) showing symptoms of leave distortion and necrotic spots (2). The leaves were collected in 1993 from Homestead, Florida, USA, desiccated, and stored at 4°C. A DNA-A (2,609 nt; KJ647290), and a DNA-B (2,545 nt; KJ647291) were cloned from EcoRI and AvaI-digestion of rolling-circle amplification products generated using random hexamers. Pairwise scores generated by the Species Demarcation Tool (SDT) indicated that the DNA-A and the DNA-B had the greatest similarity, 98.6% and 97.2%, respectively, to the DNA-A and the DNA-B of EuMV-[CU:Hav:27:07] obtained from Euphorbia heterophylla L. in Cuba (HQ896201, HQ896201) (3, 4). The common regions of the DNA components (344 nt) were 97% identical, indicating that these constitute an isolate of Euphorbia mosaic virus (EuMV-[US:Fl:PF:313:1993]).

Samples of E. heterophylla plants showing symptoms of bright foliar mosaic were collected from Homestead, Florida, in 2013. A DNA-A (2,609 nt; JQ963887) and a DNA-B (2,585 nt; JQ963888) were obtained through cloning and sequencing of XmnI-digested rolling-circle amplification products generated using random hexamers. SDT pairwise scores indicated that the DNA-A and the DNA-B had their highest identities, 98.8% and 98.1%, respectively, with those of EuMV-[US:Fl:PF:313:1993]. The common regions of the components (341 nt) were 97% identical, indicating that these constitute a bipartite begomovirus, designated EuMV-[US:Fl:Eu4]. The B component sequences differed in size due to a 40-nt deletion near the iterons in EuMV-[US:Fl:PF:313:1993]. While the presence of a begomovirus in symptomatic E. heterophylla has been known in Homestead, Florida, for many years (5), EuMV is the first virus to be associated with those disease symptoms.

DNA-A and DNA-B clones of EuMV-[US:Fl:PF:313:1993] were successfully inoculated to passionfruit ‘Lilikoi’ and Phaseolus vulgaris ‘Topcrop’ (6). Symptoms in P. edulis began as a mild mottling followed by necrotic spots, leaf deformation, and flower abortion. These symptoms are similar to those described for Passionfruit severe leaf distortion virus (from Brazil) but different from those of two other partially characterized begomoviruses (7–9). Symptoms in P. vulgaris, severe leaf distortion and stunting, were similar to those described for EuMV-YP from Mexico (10). Whitefly adults (Bemisia tabaci Genn. MEAM1) successfully transmitted EuMV from bean to bean, but not from passionfruit to either bean or passionfruit (11). P. edulis has been reported to be a poor colonization host for the MEAM1 whitefly (12).

Surveys of passionfruit in Homestead, Florida, from 2011 to 2012 failed to identify any EuMV-infected passionfruit plants, although EuMV-infected E. heterophylla plants with whiteflies were readily found. EuMV-[US:Fl:PF:313:1993] may have been transmitted from E. heterophylla to passionfruit by a whitefly that was later displaced by B. tabaci MEAM1, which first appeared in Florida in the mid-1980s (13, 14).

To our knowledge, this is the first report of EuMV as the causal agent of a disease in passionfruit and the first report of EuMV in the United States.

Accession number(s).

The sequences of EuMV-[US:Fl:PF:313:1993] were deposited in GenBank under the accession numbers KJ647290 and KJ647291 (DNA-A and DNA-B, respectively), and the sequences of EUMV-[US:Fl:Eu4] were deposited in GenBank under the accession numbers JQ963887 and JQ963888.