Properties of a citrus isolate of olive latent virus 1, a new necrovirus

Abstract

A virus was recovered by sap transmission from plants of several citrus species exhibiting or not symptoms of chlorotic dwarf (CCD), a disease recently reported from Eastern Mediterranean Turkey. The virus was identified as an isolate of olive latent virus 1 (OLV-1), originally described as a possible sobemovirus. The citrus isolate of OLV-I (OLV-1/Tk) possesses biological, morphological, physico-chemical, and ultrastructural properties similar, if not identical to those of the OLV-1 type strain and is also serologically indistinguishable from it. In addition, OLV-1/Tk has many properties, especially physico-chemical, in common with serotypes A and D of tobacco necrosis necrovirus (TNV-A and TNV-D). However, OLV-1/Tk is only very distantly related serologically to both TNV-A and D, suggesting that it can be regarded as a distinct species in the genus Necrovirus. OLV-1/Tk could not be detected in citrus tissues by ELISA or dot-blot molecular hybridization, probably because of the extremely low virus concentration. By contrast, limited virus recovery was obtained by sap inoculation and fair detection rates were afforded by PCR. OLV-1/Tk was identified in 54 of 92 (59%) citrus plants affected by CCD and in 14 of 49 (28%) symptomless plants. These results do not support the notion that there is a canse-effect relationship between OLV-1/Tk and CCD, even though the more frequent association of this virus with diseased plants remains intriguing.

Multiplex RT-PCR for detection and identification of three necroviruses that infect olive trees

“…Here we report on the design of two sets of specific primers, for each OMMV and TNV-D and on their use together with the primers specific for OLV-1 (Martelli et al 1996) (Table 1) in a multiplex PCR, aiming at the simultaneous detection and differentiation of necroviruses in olive. Due to the likely recombinant nature of OMMV between TNV-D and OLV-1, caution was taken to ensure both specificity and compatibility of the primers for each of the 3 necrovirus genome.…”

“…Thereafter, a single multiplex procedure was optimized using the primers here designed together with those specific for OLV-1 detection (Martelli et al 1996) using as template dsRNA fractions obtained from a Nicotiana benthamiana plant multiple infected with OLV-1, TNV-D and OMMV. The expected PCR products were concomitantly produced and easily distinguished by agarose gel electrophoresis (data not shown).…”

Genetic diversity of the coat protein of olive latent virus 1 isolates

“…Since then, OLV-1 has been detected in olive trees in other countries, where it either causes no symptoms or is associated with low vigor, dwarfing, bushy growth, fasciation and bifurcation of stems, or yellow and sickle-shaped leaves [1, 7-9, 25, 36, 42]. OLV-1 also has been shown to be associated with chlorotic dwarf disease of citrus in Turkey, with necrosis of tulips in Japan, and necrosis of tomato in Poland [2,20,26]. OLV-1 can infect a range of herbaceous hosts, causing chlorotic, necrotic or reddish local lesions [13].…”

Biology and molecular characterization of necroviruses affecting Olea europaea L.: a review

“…Host plants OLV-1 was recovered from olive trees, in Italy, showing low vigour, defoliation, bifurcation and fasciation of branches, as well as from symptomless trees (Gallitelli and Savino 1985;Martelli et al 1996;Merciega et al 1996), and since then its presence has been detected in other countries (Table 1). Additionally, OLV-1 can infect a variety of experimental hosts usually causing local necrosis.…”