First Report of Konjac mosaic virus in Zamioculcas zamiifolia.

Abstract

Zamioculcas zamiifolia (Lodd.) Engl. ("Zanzibar Gem," "ZZ plant") is the monotypic species of the genus belonging to the family Araceae. It is a stemless perennial plant native to Africa, from Kenya to South Africa, that produces succulent rhizomes at the base of its attractive dark green and glossy foliage. Symptoms of mosaic and foliar distortion were observed on a plant purchased at an ornamental plants shop in São Paulo state, Brazil. In order to identify the causal agent, transmission and serological tests, as well as electron microscopy (EM) observations, reverse transcription (RT)-PCR, and sequencing were carried out. EM observations revealed the presence of elongated, flexuous viral particles in foliar extracts and cytoplasmic lamellar aggregates of type II lamellar inclusions (Edwardson's classification), in thin sections. No symptoms were induced following mechanical inoculation on Chenopodium amaranticolor, C. murale, Gomphrena globosa, Nicotiana megalosiphon, N. debneyii, nor on the aroids Philodendron scandens, P. selloum, Dieffenbachia amoena, Colocasia esculenta, and Z. zamiifolia. Up to 2 months after inoculation, plants were still symptomless, and the virus was not detected by RT-PCR. The indirect ELISA tests were negative with antisera against Dasheen mosaic virus (gift from F. W. Zettler, University of Florida) and Turnip mosaic virus (gift from P. Roggero, IFA, Turin, Italy). RT-PCR performed on the original purchased ornamental plant with potyvirus-specific primers (CI-R = ACICCRTTYTCDATDATRTTIGTIGC and CI-F = GGIVVIGTIGGIWSIGGIAARTCIAC) targeting the cytoplasmic inclusion protein cistron of the potyvirus genome produced a fragment of approximately 650 bp (GenBank Accession No. KC990386). The sequence was similar to those of potyvirus species with nucleotide identity, determined by PAUP v.4.0b10 for Macintosh, ranging from 64% for Pokeweed mosaic virus (JQ609065) to 93% for Konjac mosaic virus KoMV-F (NC007913). KoMV has been detected in aroid species in Taiwan, India, Korea, Japan (1,2), Germany, and The Netherlands (3,4). This is the first report of a viral disease on Z. zamiifolia and of KoMV in the Americas. Such information along with the vegetative propagation of ZZ plants strongly suggests that KoMV is spread worldwide.