Co-infection of a novel fusagravirus and a partitivirus in a Korean isolate of Rosellinia necatrix KACC40168

ABSTRACT White root rot, caused by the ascomycete Rosellinia necatrix, is a devastating disease worldwide, particularly in fruit trees in Japan. Here we report on the biological and molecular properties of a novel bipartite double-stranded RNA (dsRNA) virus encompassing dsRNA-1 (8,931 bp) and dsRNA-2 (7,180 bp), which was isolated from a field strain of R. necatrix, W779. Besides the strictly conserved 5′ (24 nt) and 3′ (8 nt) terminal sequences, both segments show high levels of sequence similarity in the long 5′ untranslated region of approximately 1.6 kbp. dsRNA-1 and -2 each possess two open reading frames (ORFs) named ORF1 to -4. Although the protein encoded by 3′-proximal ORF2 on dsRNA-1 shows sequence identities of 22 to 32% with RNA-dependent RNA polymerases from members of the families Totiviridae and Chrysoviridae, the remaining three virus-encoded proteins lack sequence similarities with any reported mycovirus proteins. Phylogenetic analysis showed that the W779 virus belongs to a separate clade distinct from those of other known mycoviruses. Purified virions ∼50 nm in diameter consisted of dsRNA-1 and -2 and a single major capsid protein of 135 kDa, which was shown by peptide mass fingerprinting to be encoded by dsRNA-1 ORF1. We developed a transfection protocol using purified virions to show that the virus was responsible for reduction of virulence and mycelial growth in several host strains. These combined results indicate that the W779 virus is a novel bipartite dsRNA virus with potential for biological control (virocontrol), named Rosellinia necatrix megabirnavirus 1 (RnMBV1), that possibly belongs to a new virus family.

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Molecular Characterization and Infectious cDNA Clone of a Korean Isolate of Pepper mild mottle virus from Pepper

The Plant Pathology Journal ◽

10.5423/ppj.2005.21.4.361 ◽

2005 ◽

Vol 21 (4) ◽

pp. 361-368 ◽

Cited By ~ 8

Author(s):

Ju-Yeon Yoon ◽

Jin-Sung Hong ◽

Min-Jea Kim ◽

Ju-Hee Ha ◽

Gug-Seon Choi ◽

...

Keyword(s):

Molecular Characterization ◽

Cdna Clone ◽

Infectious Cdna Clone ◽

Mottle Virus ◽

Korean Isolate ◽

Pepper Mild Mottle Virus

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First Report of Powdery Mildew Caused by Golovinomyces biocellatus on Agastache rugosa in Korea

Plant Disease ◽

10.1094/pdis-03-14-0298-pdn ◽

2014 ◽

Vol 98 (9) ◽

pp. 1278-1278 ◽

Cited By ~ 1

Author(s):

S. E. Cho ◽

J. H. Park ◽

S. H. Hong ◽

I. Y. Choi ◽

H. D. Shin

Keyword(s):

Powdery Mildew ◽

Severe Disease ◽

Morphological Characteristics ◽

Control Measures ◽

Control Treatment ◽

Width Ratio ◽

Korean Isolate ◽

Pathogenicity Test ◽

Agastache Rugosa ◽

First Report

Agastache rugosa (Fisch. & C.A. Mey.) Kuntze, known as Korean mint, is an aromatic plant in the Lamiaceae. It is widely distributed in East Asian countries and is used as a Chinese traditional medicine. In Korea, fresh leaves are commonly added to fish soups and stews (3). In November 2008, several dozen Korean mints plants growing outdoors in Gimhae City, Korea, were found to be severely infected with a powdery mildew. The same symptoms had been observed in Korean mint plots in Busan and Miryang cities from 2008 to 2013. Symptoms first appeared as thin white colonies, which subsequently developed into abundant hyphal growth on stems and both sides of the leaves. Severe disease pressure caused withering and senescence of the leaves. Voucher specimens (n = 5) were deposited in the Korea University Herbarium (KUS). Appressoria on the mycelium were nipple-shaped or nearly absent. Conidiophores were 105 to 188 × 10 to 13 μm and produced 2 to 4 immature conidia in chains with a sinuate outline, followed by 2 to 3 cells. Foot-cells of the conidiophores were straight, cylindrical, slightly constricted at the base, and 37 to 58 μm long. Conidia were hyaline, ellipsoid to barrel-shaped, measured 25 to 40 × 15 to 23 μm (length/width ratio = 1.4 to 2.1), lacked distinct fibrosin bodies, and showed reticulate wrinkling of the outer walls. Primary conidia were obconically rounded at the apex and subtruncate at the base. Germ tubes were produced at the perihilar position of conidia. No chasmothecia were observed. The structures described above were typical of the Oidium subgenus Reticuloidium anamorph of the genus Golovinomyces. The measurements and morphological characteristics were compatible with those of G. biocellatus (Ehrenb.) V.P. Heluta (1). To confirm the identification, molecular analysis of the sequence of the internal transcribed spacer (ITS) region of ribosomal DNA (rDNA) of isolate KUS-F27200 was conducted. The complete ITS rDNA sequence was amplified using primers ITS5 and P3 (4). The resulting 514-bp sequence was deposited in GenBank (Accession No. KJ585415). A GenBank BLAST search of the Korean isolate sequence showed >99% similarity with the ITS sequence of many G. biocellatus isolates on plants in the Lamiaceae (e.g., Accession Nos. AB307669, AB769437, and JQ340358). Pathogenicity was confirmed by gently pressing diseased leaf onto leaves of five healthy, potted Korean mint plants. Five non-inoculated plants served as a control treatment. Inoculated plants developed symptoms after 7 days, whereas the control plants remained symptomless. The fungus present on inoculated plants was identical morphologically to that observed on the original diseased plants. The pathogenicity test was repeated with identical results. A powdery mildew on A. rugosa caused by G. biocellatus was reported from Romania (2). To our knowledge, this is the first report of powdery mildew caused by G. biocellatus on A. rugosa in Korea. The plant is mostly grown using organic farming methods with limited chemical control options. Therefore, alternative control measures should be considered. References: (1) U. Braun and R. T. A. Cook. Taxonomic Manual of the Erysiphales (Powdery Mildews), CBS Biodiversity Series No. 11. CBS, Utrecht, 2012. (2) D. F. Farr and A. Y. Rossman. Fungal Databases. Syst. Mycol. Microbiol. Lab., online publication, USDA ARS, retrieved 17 February 2014. (3) T. H. Kim et al. J. Sci. Food Agric. 81:569, 2001. (4) S. Takamatsu et al. Mycol. Res. 113:117, 2009.

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Draft Genome Sequence and Transcriptional Analysis of Rosellinia necatrix Infected with a Virulent Mycovirus

Phytopathology ◽

10.1094/phyto-11-17-0365-r ◽

2018 ◽

Vol 108 (10) ◽

pp. 1206-1211 ◽

Cited By ~ 4

Author(s):

Takeo Shimizu ◽

Satoko Kanematsu ◽

Hajime Yaegashi

Keyword(s):

Genome Sequence ◽

Molecular Mechanisms ◽

Plant Cell Wall ◽

Draft Genome ◽

Transcriptional Analysis ◽

Draft Genome Sequence ◽

Effective Control ◽

Economic Losses ◽

Rosellinia Necatrix ◽

Cell Wall Degrading Enzymes

Understanding the molecular mechanisms of pathogenesis is useful in developing effective control methods for fungal diseases. The white root rot fungus Rosellinia necatrix is a soilborne pathogen that causes serious economic losses in various crops, including fruit trees, worldwide. Here, using next-generation sequencing techniques, we first produced a 44-Mb draft genome sequence of R. necatrix strain W97, an isolate from Japan, in which 12,444 protein-coding genes were predicted. To survey differentially expressed genes (DEGs) associated with the pathogenesis of the fungus, the hypovirulent W97 strain infected with Rosellinia necatrix megabirnavirus 1 (RnMBV1) was used for a comprehensive transcriptome analysis. In total, 545 and 615 genes are up- and down-regulated, respectively, in R. necatrix infected with RnMBV1. Gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses of the DEGs suggested that primary and secondary metabolism would be greatly disturbed in R. necatrix infected with RnMBV1. The genes encoding transcriptional regulators, plant cell wall-degrading enzymes, and toxin production, such as cytochalasin E, were also found in the DEGs. The genetic resources provided in this study will accelerate the discovery of genes associated with pathogenesis and other biological characteristics of R. necatrix, thus contributing to disease control.

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Rosellinia necatrix. [Distribution map].

Distribution Maps of Plant Diseases ◽

10.1079/dmpd/20056500306 ◽

1976 ◽

Author(s):

Keyword(s):

South Africa ◽

New York ◽

Central America ◽

West Indies ◽

Central African Republic ◽

Rio Grande ◽

Republic Of Georgia ◽

Rosellinia Necatrix ◽

Distribution Map ◽

New Distribution

Abstract A new distribution map is provided for Rosellinia necatrix Prill. Hosts: Various. Information is given on the geographical distribution in AFRICA, Central African Republic, Ethiopia, Kenya, Morocco, Mozambique, South Africa, Zaire, ASIA, China, India (Himachal Pradesh), Iran, Iraq, Israel, Japan, Korea, Lebanon, Philippines, Turkey, USSR (Caucasus, Crimea) (Republic of Georgia), Middle, Asia, AUSTRALASIA & OCEANIA, New Zealand, EUROPE, Austria, Britain, Bulgaria, Cyprus, France, Germany, Greece, Italy, Portugal (Azores), Romania, Spain, Switzerland, USSR (S.), Yugoslavia, NORTH AMERICA, Mexico, USA (Alabama, California, Indiana, Michigan, New York, Ohio), CENTRAL AMERICA & WEST INDIES, Dominican Republic, SOUTH AMERICA, Argentina, Brazil (Rio Grande, Sao Paulo), Colombia, Uruguay.

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Efficacy of Potential Control Agents Against Rosellinia necatrix and Their Physiological Impact on Avocado

Plant Disease ◽

10.1094/pdis-08-20-1751-re ◽

2021 ◽

Author(s):

Phinda Magagula ◽

Nicky Taylor ◽

Velushka Swart ◽

Noëlani van den Berg

Keyword(s):

Integrated Management ◽

Integrated Approach ◽

Dry Mass ◽

Persea Americana ◽

Effective Control ◽

Rosellinia Necatrix ◽

Potential Control ◽

Greenhouse Trial

Rosellinia necatrix is the causal agent of white root rot (WRR), a fatal disease affecting many woody plants, including avocado (Persea americana). As with other root diseases, an integrated approach is required to control WRR. No fully effective control methods are available, and no chemical or biological agents against R. necatrix have been registered for use on avocado in South Africa. Fluazinam has shown promising results in the greenhouse and field in other countries, including Spain. The current study aimed to investigate the potential of a fumigant, chloropicrin, and biological control agents (B-Rus, Beta-Bak, Mity-Gro, and Trichoderma) against R. necatrix both in vitro and in vivo as compared with fluazinam. In a greenhouse trial, results showed that Trichoderma and B-Rus were as effective as fluazinam at inhibiting R. necatrix in vitro and suppressed WRR symptoms when applied before inoculation with R. necatrix. In contrast, Mity-Gro and Beta-Bak failed to inhibit the pathogen in vitro and in the greenhouse trial, despite application of the products to plants before R. necatrix infection. Fluazinam suppressed WRR symptoms in plants when applied at the early stages of infection, whereas chloropicrin rendered the pathogen nonviable when used as a preplant treatment. Plants treated with Trichoderma, B-Rus, and fluazinam sustained dry mass production and net CO2 assimilation by maintaining the green leaf tissues despite being infected with the pathogen. This study has important implications for the integrated management of WRR.

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Rosellinia necatrix. [Distribution map].

Distribution Maps of Plant Diseases ◽

10.1079/dmpd/20046500306 ◽

1987 ◽

Author(s):

Keyword(s):

South Africa ◽

New York ◽

Central America ◽

West Indies ◽

Central African Republic ◽

Rio Grande ◽

Rosellinia Necatrix ◽

Rio Grande Do Sul ◽

Distribution Map ◽

New Distribution

Abstract A new distribution map is provided for Rosellinia necatrix Prill. Hosts: Various. Information is given on the geographical distribution in Africa, Central African Republic, Ethiopia, Kenya, Morocco, Mozambique, South Africa, Zaire, Asia, China, India, Himachal Pradesh, Iran, Iraq, Israel, Japan, Korea, Lebanon, Philippines, Taiwan, Turkey, USSR, Caucasus, Crimea, Georgia, Middle Asia, Australasia & Oceania, New Zealand, Europe, Austria, Britain, Bulgaria, Cyprus, France, Germany, Greece, Italy, Portugal, Azores, Romania, Spain, Switzerland, Yugoslavia, North America, Mexico, USA, Alabama, California, Indiana, Michigan, New York, Ohio, Central America & West Indies, Dominican Republic, South America, Argentina, Brazil, Rio Grande do Sul, Sao Paulo, Colombia, Uruguay.

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