Sequence analysis of the capsid protein gene of an isolate of Apple stem grooving virus, and its survey in Southern Brazil

Abstract

Apple stem grooving virus (ASGV) is one of the most important viruses infecting fruit trees. This study aimed at the molecular characterization of ASGV infecting apple (Malus domestica) plants in Santa Catarina (SC). RNA extracted from plants infected with isolate UV01 was used as a template for RT-PCR using specific primers. An amplified DNA fragment of 755 bp was sequenced. The coat protein gene of ASGV isolate UV01 contains 714 nucleotides, coding for a protein of 237 amino acids with a predicted Mr of approximately 27 kDa. The nucleotide and the deduced amino acid sequences of the coat protein gene showed identities of 90.9% and 97.9%, respectively, with a Japanese isolate of ASGV. Very high amino acid homologies (98.7%) were also found with Citrus tatter leaf capillovirus (CTLV), a very close relative of ASGV. These results indicate low coat protein gene variability among Capillovirus isolates from distinct regions. In a restricted survey, mother stocks in orchards and plants introduced into the country for large scale fruit production were indexed and shown to be infected by ASGV (20%), usually in a complex with other (latent) apple viruses (80%).

High-throughput sequencing reveals small RNAs involved in ASGV infection

“…It is a positive-sense RNA virus with a genome of approximately 6.5 kb, which is organised into two overlapping open reading frames (ORFs) [2]. ASGV infection is mostly symptomless (latent) in apple cultivars, depending on the virus strain, however some cultivars are susceptible and may develop severe symptoms such as xylem pitting and grooving, phloem necrosis and the complete decay of the tree [3]. …”

Identification and characterization of Apple stem grooving virus causing leaf distortion on pear (Pyrus pyrifolia) in Taiwan

“…ASGV is a graft-transmissible viral pathogen that frequently occurs in Rosaceae fruit trees such as apple (Jones and Aldwinckle 1990;Magome et al 1997;Nickel et al 2001), pear (Jones and Aldwinckle 1990;Shim et al 2004;Yoshikawa et al 1996), apricot Fig. 4 Phylogenetic relationships of the ASGV coat protein gene of Taiwanese isolates TS1 and TS2, Japanese isolate AGJP-22 from imported pear scion and fifteen other isolates.…”

Simultaneous detection of four viruses affecting apple and pear by molecular hybridization using a polyprobe

“…The complete coat protein gene of these four Brazilian viral isolates have been previously molecularly characterized: ASGV, UV01 isolate (NICKEL et al, 2001), ACLSV, BR1 isolate (SILVA et al, 2008), ASPV, br1 isolate (RADAELLI et al, 2006) and ApMV, M003 isolate (FAJARDO et al, 2011) in studies developed in the Virology Laboratory at Embrapa Grape & Wine, Bento Gonçalves-RS, Brazil.…”

“…Virus infections are a common occurrence in apples and pears grown in Brazil (NICKEL et al, 2001). Among apples (Malus domestica) and pears (Pyrus spp.)…”