A virus with isometric particles c. 30 nm in diameter and angular contour was isolated by inoculation of sap from a Turkish grapevine showing very mild fanleaf symptoms. In sucrose density gradient centrifugation the virus sedimented as three components: T (empty shells), M (particles containing a RNA species with mol. wt 1.4 x 106 Da) and B (particles containing a RNA species with mol. wt 2.2 x 106 Da).The coat protein subunits were of a single type with Mr ca. 55.5 KDa. An antiserum with a titer of 1:256 was raised, which did not react with healthy plant antigens. A fragment 1,274 nt in size, representing the 3 terminal region of genomic RNA-2 was sequenced. Direct comparison analysis with sequences from the same region from GenBank-EMBL databases revealed levels of homology with other grapevine nepoviruses, the closest being GCMV (62% identity at the amino acid level), AILV and TBRV (49%identity at the amino acid level with both). Based on the determined sequence, specific primers were designed which in RT-PCR assays amplified a 343 bp fragment virus from grapevine crude tissue extracts. Infected N. occidentalis leaves had a cytopathology comparable to that of nepovirus infections, typical virus-containing tubules, mostly associated with plasmodemata. The physicochemical and ultrastructural properties of this virus resembled very much those of nepoviruses. However, it was serologically unrelated to 17 different members of this genus, including all those recorded from gapevines. These results support the notion that the Turkish grapevine virus is a hitherto undescribed member of the genus Nepovirus belonging in subgroup B, for which the name Grapevine Anatolian ringspot virus (GARSV) is proposed.
Properties of a previously undescribed nepovirus from south-east Anatolia.
De Stradis A;Boscia D;
2003
Abstract
A virus with isometric particles c. 30 nm in diameter and angular contour was isolated by inoculation of sap from a Turkish grapevine showing very mild fanleaf symptoms. In sucrose density gradient centrifugation the virus sedimented as three components: T (empty shells), M (particles containing a RNA species with mol. wt 1.4 x 106 Da) and B (particles containing a RNA species with mol. wt 2.2 x 106 Da).The coat protein subunits were of a single type with Mr ca. 55.5 KDa. An antiserum with a titer of 1:256 was raised, which did not react with healthy plant antigens. A fragment 1,274 nt in size, representing the 3 terminal region of genomic RNA-2 was sequenced. Direct comparison analysis with sequences from the same region from GenBank-EMBL databases revealed levels of homology with other grapevine nepoviruses, the closest being GCMV (62% identity at the amino acid level), AILV and TBRV (49%identity at the amino acid level with both). Based on the determined sequence, specific primers were designed which in RT-PCR assays amplified a 343 bp fragment virus from grapevine crude tissue extracts. Infected N. occidentalis leaves had a cytopathology comparable to that of nepovirus infections, typical virus-containing tubules, mostly associated with plasmodemata. The physicochemical and ultrastructural properties of this virus resembled very much those of nepoviruses. However, it was serologically unrelated to 17 different members of this genus, including all those recorded from gapevines. These results support the notion that the Turkish grapevine virus is a hitherto undescribed member of the genus Nepovirus belonging in subgroup B, for which the name Grapevine Anatolian ringspot virus (GARSV) is proposed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
