Related Experiment Videos
A novel mycovirus associated to Alternaria alternata comprises a distinct lineage in Partitiviridae
André da Silva Xavier1, Ana Paula Oliveira de Barros2, Márcio Tadeu Godinho1
1Departamento de Fitopatologia, Instituto de Biotecnologia Aplicada à Agropecuária (BIOAGRO), Universidade Federal de Viçosa, Viçosa, MG 36570-900, Brazil.
Abstract:
In the present work, we report a novel mycovirus that infects Alternaria alternata. The mycovirus has isometric particles of approximately 30nm and the genome consists of two molecules of dsRNA, dsRNA1 with 1833bp, encoding a putative RNA-dependent RNA polymerase (RdRp) and dsRNA2, with 1680bp in length, encoding the putative capsid protein (CP). RdRp analysis revealed low amino acid identity with RdRps with species in the genus Gammapartitivirus, and the alignment of the RdRp revealed all the six conserved motifs present in members of Partitiviridae. The putative coat protein (CP) analysis revealed similarity with the putative CP of Botryosphaeria dothidea partitivirus 1 (BdPV1), a divergent partitivirus. We propose that Alternaria alternata partitivirus 1 (AtPV1) is a novel species and comprises a distinct lineage related to genus Gammapartitivirus in the family Partitiviridae, apparently on the threshold of radiation of a new genus, together with BdPV1. Vertical transmission tests showed that AtPV1 was transmitted to 100% conidial progeny and standard curing was unable to eliminate it from the host, characterizing it as a persistent virus. The absence of a virus-free isogenic lineage prevented us from accessing the details of the interaction between AtPV1 and A. alternata. Therefore, it remains unclear whether the morphological plasticity observed or the inability of the A. alternata isolate AVi1 to cause disease in plants is associated with AtPV1 infection.
Insights
A novel mycovirus, Alternaria alternata partitivirus 1 (AtPV1), was discovered infecting Alternaria alternata. This persistent virus is transmitted vertically and may represent a new genus within the Partitiviridae family.
Area of Science:
- Mycology
- Virology
- Plant Pathology
Background:
- Alternaria alternata is a significant fungal pathogen.
- Mycoviruses can influence host characteristics and pathogenicity.
- Partitiviruses are a family of double-stranded RNA viruses infecting fungi.
Purpose of the Study:
- To characterize a novel mycovirus infecting Alternaria alternata.
- To determine the phylogenetic relationship of the new mycovirus.
- To investigate the transmission and persistence of the mycovirus within its host.
Main Methods:
- Electron microscopy for particle morphology.
- Genome sequencing to determine dsRNA molecule sizes and gene content.
- Bioinformatic analysis of putative RNA-dependent RNA polymerase (RdRp) and capsid protein (CP).
- Vertical transmission assays and virus curing experiments.
Main Results:
- A novel mycovirus, named Alternaria alternata partitivirus 1 (AtPV1), was identified with isometric particles (approx. 30nm).
- The AtPV1 genome comprises two dsRNA molecules encoding putative RdRp and CP.
- Phylogenetic analysis suggests AtPV1 is a novel species related to the genus Gammapartitivirus, potentially forming a new genus with Botryosphaeria dothidea partitivirus 1.
- AtPV1 demonstrates 100% vertical transmission to conidial progeny and is resistant to standard curing methods, indicating persistence.
Conclusions:
- AtPV1 represents a novel species and lineage within the family Partitiviridae.
- The virus is persistently transmitted and difficult to eliminate from the host.
- The impact of AtPV1 infection on A. alternata's morphology and pathogenicity remains undetermined due to the lack of a virus-free isogenic line.