Naslov
MOLECULAR VARIABILITY OF CITRUS TRISTEZA VIRUS DETERMINED BY ASSYMMETRIC PCR-ELISA AND SSCP

Autori
Černi, Silvija ; Martins , Vera ; Krajačić, Mladen ; Škorić, Dijana ; Nolasco, Gustavo

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Adenoviruses-basic biology to gene therapy ; book of abstracts / Majhen, Dragomira ; Ambriović-Ristov, Andreja - Zagreb : DTP centar, 2008, 20-20

ISBN
978-953-96567-6-6

Skup
Adenoviruses-basic biology to gene therapy

Mjesto i datum
Zadar, Hrvatska, 23.09.2008. - 24.09.2008

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
CTV; PCR-ELISA; SSCP

Sažetak
Citrus tristeza Closterovirus (CTV) is one of the most important viral pathogens of citrus. CTV virions are phloem-limited flexuous filaments of 2000x11 nm in size. With its monopartite, single-stranded, positive-sense RNA genome of 19.3 kb organized into 12 open reading frames (ORFs), CTV is considered to be the largest single-stranded RNA plant virus characterized so far. Aphids naturally spread the virus but it is also easily transmitted by grafting. Depending on a virus strain, scion cultivar and rootstock, CTV can induce one of the three main syndromes: “ quick decline” , “ stem pitting” and “ seedling yellows” , but some mild strains can go unnoticed because of the lack of visible symptoms. In nature, CTV usually exists as a mixture of strains. Due to a low concentration and seasonal variations of the virus in field trees, the detection is difficult and it is necessary to use methods for sensitive and reliable CTV diagnosis and strain typing. Five CTV positive Croatian citrus samples have been strain-typed using asymmetric PCR ELISA and single strand conformation polymorphism (SSCP) analysis. CTV coat protein (CP) gene was amplified in an immunocapture asymmetric RT-PCR (IC/RT-PCR) and amplicons were hybridized with the eight CTV group-specific probes. In addition, SSCP analysis of CTV CP gene was performed. According to the probe-typing results, all five analyzed samples were mix-infected and showed homology to CTV phylogenetic groups 2 and M which represent mild, asymptomatic, CTV strains. One sample also showed homology to probe from group 4 and another to probe from group 3a. Groups 3a and 4 encompass very severe, “ quick decline” strains and group 3a can additionally induce “ stem pitting” syndrome. Multiple band patterns in SSCP profiles confirmed mixed-infectious in all analyzed samples. Probe-typing results were further corroborated by cloning and sequencing of IC/RT-PCR amplicons. Phylogenetic analysis was in accordance with the probe-typing group-classification for all the samples. Neither of the amplicons, even from the same virus strain, had the same sequence. All the results obtained represent molecular confirmation of the considerable biological diversity of CTV found in Croatian citrus samples.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

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