New Zealand Stresses that It Is High Plains Virus Free, and the Virus Struggles with an Identity Crisis.

Abstract

High Plains virus (HPV), a tentative member of the genus Emaravirus, causes a potentially serious economic disease in cereals. Recently, in this journal, Tatineni et al. (1) mistakenly reported HPV as being present in New Zealand, citing the paper by Lebas et al. from 2005 (2). The 2005 report clearly states that New Zealand is HPV free in both the abstract and the introduction (2). To date, HPV is not known to occur in New Zealand. The Ministry for Primary Industries of New Zealand has very strict regulations in place to prevent the importation of unwanted organisms such as HPV. For example, the importation of Zea mays seeds must follow the requirements stated in Import Health Standard 155.02.05 (for seed for sowing) (3), which includes testing of HPV by enzyme-linked immunosorbent assay (ELISA) or PCR. The Tatineni et al. statement (1) will mislead regulatory officials of New Zealand’s trading partners who regularly monitor world microbe dynamics in the scientific literature. In fact, there are plant biosecurity actions in place (4) that directly affect New Zealand’s international trade when a regulated plant virus like HPV is reported as present. The situation above is aggravated by the lack of a definitive virus name yet to be ruled on by the Emaravirus Study Group, Plant Viruses Subcommittee, International Committee on Taxonomy of Viruses (ICTV). Historically, many names have been used to refer to this virus. The name Wheat spot mosaic virus (WSpM virus) was given to a virus associated with High Plains disease studied in the 1950s (5). WSpM virus-diseased samples were not preserved, and therefore it is not possible to do comparative studies (6, 7). The name High Plains virus, which causes red striping symptoms on maize, was first coined by Jensen et al. in 1996 (8). Subsequently, a virus associated with High Plains disease also eliciting red striping symptoms was partially characterized and sequenced and the name maize red stripe virus (MRStV) was introduced as a replacement for HPV (9). A note added in proof for this paper suggested the name of Wheat mosaic virus (WMoV) based on the fact that the virus is more prevalent in wheat than in maize (9). WMoV was subsequently referred to into recent publications (10, 11). All proposed names reflect diverse symptoms observed among infected wheat and sweet corn varieties and the fact that the virus is commonly detected in mixed infections. HPV is reported to coinfect with Wheat streak mosaic virus (WSMV), Triticum mosaic virus (TriMV), Barley yellow dwarf virus PAV (BYDVPAV), and Cereal yellow dwarf virus RPV (CYDV-RPV) in the Great Plains region of the United States (10, 12). In general, all proposed names do not conflict with ICTV definitions of species, construction of names, and/or rules for orthography. The fact that the HPV name does not refer to a specific host name, but to a geographical location, and its elusiveness for years may have sparked this populated name list. However, other plant viruses have been named based only on geographical origin; examples are the tombusviruses Havel River virus, Lato River virus, and Neckar River virus, which are all ICTV-approved names (13). MacDiarmid et al. in 2013 (4) had proposed and justified new recommendations for plant virus characterization and classification in the context of new virus discovery. Both the ICTV and MacDiarmid et al. (4) are seeking (i) fluent communication among scientists, (ii) stability, (iii) to not use names that might cause error or confusion, and (iv) to avoid the unnecessary creation of names as stated by the ICTV principles of nomenclature. Certainly, HPV is not known to be present in New Zealand, and acknowledgment of the HPV-free status of New Zealand is urgently required. This also implies the requirement of a more meticulous review of manuscripts by referees and editors of the journal. Regarding HPV naming, less confusion in the long term will be expected if HPV is kept as a name, which is justified by the existence of precedent plant virus naming using geographical location markers and HPV’s broader usage in literature and sequence repositories.