Molecular Characterization of a Chrysovirus Isolated From the Citrus Pathogen Penicillium crustosum and Related Fungicide Resistance Analysis

Abstract

Penicillium sp. are damaging to a range of foods and fruits including citrus. To date, double-stranded (ds)RNA viruses have been reported in most Penicillium species but not in citrus pathogen P. crustosum . Here we report a novel dsRNA virus, designated as Penicillium crustosum chrysovirus 1 (PcCV1) and isolated from P. crustosum strain HS-CQ15. PcCV1 genome comprises four dsRNA segments, referred to as dsRNA1, dsRNA2, dsRNA3, and dsRNA4, which are 3600, 3177, 3078, and 2808 bp in length, respectively. Sequence analysis revealed the presence of four open reading frames (ORFs) in the PcCV1 genome. ORF1 in dsRNA1 encodes a putative RNA-dependent RNA polymerase (RdRp) and ORF2 in dsRNA2 encodes a putative coat protein (CP). The two remaining ORFs, ORF3 in dsRNA3 and ORF4 in dsRNA4, encode proteins of unknown function. Phylogenetic analysis based on RdRp sequences showed that PcCV1 clusters with other members of the genus Chrysovirus , family Chrysoviridae . Transmission electron microscope (TEM) analysis revealed that the PcCV1 visions are approximately 40 nm in diameter. Regarding biological effects of PcCV1, HS-CQ15 harboring the chrysovirus exhibited no obvious difference in colony morphology under fungicide-free conditions but decreased resistance to demethylation inhibitor (DMI)-fungicide prochloraz, as compared to PcCV1-cured strain. Here we provide the first evidence of a virus present in citrus pathogenic fungus P. crustosum and the chrysovirus-induced change in fungicide-resistance of its host fungus.

Molecular characterization of an Egyptian isolate of Penicillium chrysogenum virus

“…The multi-segmented genomes may consist of three (trichrysoviruses; (Li et al, 2013), four (tetrachrysoviruses; Covelli et al, 2004;Jiang and Ghabrial 2004), five (cinquechrysoviruses; Darissa et al, 2011;Urayama et al, 2012) or seven linear dsRNA segments (settechrysoviruses; Zhai et al, 2018), with tetrachrysoviruses being the most commonly reported. PcV-18 reported in this study belongs to tetrarchrysoviruses which is the case for its most closely related viruses; PcV and PiCV (Jiang and Ghabrial 2004;Zhang et al, 2019). Most members of Chrysoviridae have been reported from fungi, however plants and probably insects have been recently found to host chrysoviruses (Li et al, 2013;Shi et al, 2016;Zhang et al, 2017).…”

“…One of the most studied species of this genus is P. chrysogenum, which has been widely used as a source of β-lactam antibiotic (Guzmán-Chávez et al, 2018). Several mycoviruses have been reported to infect Penicillium species such as P. chrysogenum (Banks et al, 1969), P. digitatum (Niu et al, 2018), P. crustosum (Wang et al, 2019) and P. janthinellum (Sato et al, 2020).…”

A novel hexa‐segmented dsRNA mycovirus confers hypovirulence in the phytopathogenic fungus Diaporthe pseudophoenicicola

“…In this study, a hexa‐segmented tentative chrysovirus, designated as Diaporthe pseudophoenicicola chrysovirus 1 (DpCV1), isolated from D. pseudophoenicicola was first reported. Members of the family Chrysoviridae possess different genome segments ranging from three to five (Darissa et al ., 2011; Urayama et al ., 2014; Wang et al ., 2019). Recently, a seven‐segmented tentative chrysovirus was reported in Colletotrichum fructicola (Zhai et al ., 2018).…”

“…A typical chrysovirus genome is composed of four segmented dsRNAs of 2.4–3.6 kbp in length that are separately encapsulated in virus particles with approximately 40 nm diameter (Ghabrial et al ., 2018; Wang et al ., 2019). The largest ORF encodes RNA‐dependent RNA polymerase (RdRp), while the other three ORFs encode a major capsid protein (CP), a putative protease (P3), and an unknown function protein (P4), respectively (Jiang and Ghabrial, 2004).…”

“…Mycoviruses with double-stranded RNA (dsRNA) genomes are now categorized into seven families, including Chysoviridae, Partitiviridae, Totiviridae, Reoviridae, Megabirnaviridae, Quadriviridae, and Endornaviridae (Ghabrial et al, 2015). Among these, the Chrysoviridae family has been characterized earlier in Penicillium chrysogenum, Magnaporthe oryzae, Aspergillus fumigatus, and C. nitschkei (Edmondson et al, 1984;Liu et al, 2007;Jamal et al, 2010;Urayama et al, 2010), recently in Colletotrichum species, Alternaria species, Botryosphaeria dothidea, and P. crustosum (Wang et al, 2014(Wang et al, , 2019Zhong et al, 2016;Okada et al, 2018;Zhai et al, 2018). However, up to now, there is no evidence on inhabitant of any mycovirus in D. pseudophoenicicola.…”