scispace - formally typeset
Search or ask a question
Posted Content•DOI•

Ecology and Epidemiology of Wheat Curl Mite and Mite-Transmissible Viruses in Colorado and Insights into the Wheat Virome

Tessa Albrecht1, Samantha White1, Marylee L. Layton1, Mark D. Stenglein1, Scott D. Haley1, Punya Nachappa1 •
Colorado State University1
10 Aug 2020-bioRxiv (Cold Spring Harbor Laboratory)-
TL;DR: Variation in WSMV resistance among wheat varieties; however a variety that harbored dual resistance to mite and W SMV had lower virus titer compared to varieties that contained single resistance gene, which suggests that pyramiding genes will ensure improved and durable resistance.
Abstract: The wheat curl mite (WCM)-transmissible wheat streak disease complex is the most serious disease of wheat in the U.S. Great Plains. In the current study, we determined the genetic variability in WCM and mite-transmitted viruses in Colorado and identified sources of resistance in Colorado wheat germplasm to wheat streak disease complex. We identified two distinct genotypes of WCM, Type 1 and Type 2 based on the ribosomal ITS1 region. Both genotypes were found to co-exist throughout the wheat producing regions of Colorado. Analysis of the whole genome and partial coat protein sequences revealed rich diversity of wheat streak mosaic virus (WSMV) and High Plains wheat mosaic virus (HPWMoV) isolates collected from Colorado, whereas triticum mosaic virus (TriMV) showed low sequence variability. Analysis of WSMV isolates revealed two novel isolates and one that was 100% similar to a new variant of WSMV from Kansas. Interestingly, between 2-4 genotypes of all 8 RNA segments of HPWMoV were identified, which suggests new variants of emaraviruses and co-occurrence of multiple strains within host populations. Several novel viruses including mycoviruses were identified for the first time in Colorado. We found variation in WSMV resistance among wheat varieties; however a variety that harbored dual resistance to mite and WSMV had lower virus titer compared to varieties that contained single resistance gene. This suggests that pyramiding genes will ensure improved and durable resistance. Future research may be aimed at elucidating the dynamics, diversity, and distribution of the new WSMV and HPWMoV isolates and their responses to wheat genotypes.

Summary (2 min read)

Jump to: [Wheat Curl Mite and Plant Tissue Collection] – [Virus Detection and Quantification] – [Wheat Virome Analysis] – [Wheat Germplasm and Virulence Test] – [Virus Occurence in Colorado] – [Identification of Virus Genotypes] – [Virus Resistance in Variety Trial] and [Discussion]

Wheat Curl Mite and Plant Tissue Collection

  • Plants were examined using a dissecting microscope for the presence of WCMs.
  • Plants were grown in gallon pots with 2-3 plants per pot in Promix HP © soil.
  • Additionally, leaf tissues were tested for presence of WSMV, TriMV and HPWMoV.

Virus Detection and Quantification

  • Total RNA was extracted from approximately 40 mg homogenized leaf tissues obtained from various sources described above, lysed in Trisure® (Bioline Meridian Bioscience) using Direct-zol® RNA Purification Kit (Zymo Research, CA, USA) according to the manufacturer's recommendations.
  • The quantity of RNA was approximated using a NanoDrop One spectrophotometer (Thermo Fisher Scientific, MA, USA) and stored at -80°C until virus quantification.
  • To detect and quantify WSMV and TriMV, approximately 50 ng of RNA was used in a previously published qRT-PCR duplex assay (Price et al. 2010) with the TaqMan® RNA-to-Ct™ 1-step kit (Applied Biosystems™, ThermoFisher Scientific) on a QuantStudio™3 Real-Time PCR system (Applied Biosystems™, ThermoFisher Scientific).
  • Field samples with CQ values above the lower detection limit, as defined by the standard curves described below, were considered to be positive for the specified virus.
  • To detect HPWMoV, complementary DNA (cDNA) was synthesized from 1 μg of total RNA using the Verso® cDNA Synthesis Kit (ThermoFisher Scientific).

Wheat Virome Analysis

  • Four leaf tissue samples that previously tested positive for WSMV from Larimer county., positive for WSMV and TriMV from Bent county., positive for WSMV and HPWMoV from Phillips county., and positive for WSMV and TriMV from Kit Carson county.
  • After all filtering operations, an average of 0.25x10 6 reads (3%) remained per dataset.
  • Then, analysis of SNPs for the viruses from assembled virome data were performed using the Tablet software program to determine genetic diversity.
  • Lastly, the raw sequence data was deposited in the NCBI Sequence Read Archive (SRA) repository under submission number SUB7870854.
  • Phylogenetic analysis of the complete sequences of the nucleoprotein encoding RNA3 segments of members of both groups of HPWMoV and three variants all from the Phillips county sample, shows version Colorado RNA3C (MT762120) is similar to isolates from OH/TX or group A (Fig. 5 ).

Wheat Germplasm and Virulence Test

  • A natural infection of wheat streak mosaic virus was observed in the Colorado State University Irrigated Variety Performance Trial (IVPT) at Burlington, CO, in 2019.
  • The trial included 24 different genotypes (released varieties and experimental lines), planted in a randomized complete block design with three replications.
  • To quantify virus titer in wheat varieties, 10 leaf samples were collected on June 21, 2019.
  • All ten leaves were stacked, and a small section of tissue was cut from the center of the stack.

Virus Occurence in Colorado

  • Survey of WCM-transmitted viruses revealed the presence of all three economicallyimportant viruses in Colorado, WSMV, TriMV and HPWMoV (Fig. 2 ).
  • Of the 40 symptomatic samples tested, 38 were positive for one or more WCM-transmitted viruses.
  • WSMV was found in all surveyed counties (Fig. 2.

Identification of Virus Genotypes

  • To determine the genetic variability among WSMV isolates in Colorado, the authors sequenced a portion of the WSMV-NIb region and performed phylogenetic analyses with isolates from other wheat producing states in the U.S. and other regions of the world.
  • Interestingly, an isolate, Larimer county 1, was 100% similar to a Kansas isolate (MK318278) that was collected from a wheat variety carrying the Wsm2 virus resistance gene that is known to confer resistance to WSMV (Fellers et al. 2019) .
  • The isolate Larimer county 2 collected from same location as the Larimer county 1 isolate, appeared to be genetically distinct from other isolates in the U.S.
  • In contrast, to the genetic diversity in WSMV isolates, there was limited variability in TriMV isolates collected in Colorado compared to that of other sequenced isolates.
  • Phylogenetic analysis reveals two distinct groups of the HPWMoV isolates among available HPWMoV nucleoprotein sequences as observed by previous studies (Stewart 2016) .

Virus Resistance in Variety Trial

  • Wheat varieity trial included a combination of 24 public and private varieties and experimental lines.
  • Seed companies with entries in the variety trials included AgriMaxx Wheat, AgriPro Syngenta, Dyna-Gro Seed, Limagrain Cereal Seeds, and WestBred Bayer.
  • The gerplasm included varieties with no known resistance, a single resistance marker to either WCM (WCM6D) or WSMV (Wsm2), and one variety, Guardian, with both resistance markers, WCM6D and Wsm2 (Table 4 ).

Discussion

  • Mite-vectored wheat viruses continue to cause significant yield losses in Colorado.
  • Wheat virome analysis confirmed the presence of known viruses such as WSMV, TriMV and HPWMoV, but also revealed presence of several mycoviruses and a novel Ixeridium yellow mottle virus 2 from Colorado wheat samples.
  • The genetic diversity of WSMV has been evaluated among various isolates in the U.S. and from around the world by sequencing the coat protein (CP) (Robinson and Murray 2013) and more recent whole genome sequencing (Schubert et al. 2015) .
  • There have been reports of increasing mite populations and virus infection in resistant varieties (Tatineni and Hein 2018) .

Did you find this useful? Give us your feedback

Figures (10)

Content maybe subject to copyright    Report

1
Ecology and Epidemiology of Wheat Curl Mite and Mite-Transmissible Viruses in 1
Colorado and Insights into the Wheat Virome 2
3
Tessa Albrecht
1
, Samantha White
1
, Marylee Layton
2
, Mark Stenglein
2
, Scott Haley
3
4
and Punya Nachappa
1
5
1
Department of Agricultural Biology, Colorado State University, 307 University Ave, Fort 6
Collins, CO 80523 7
2
Department of Microbiology, Immunology, and Pathology, College of Veterinary 8
Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, 9
U.S.A. 10
3
Department of Soil and Crop Sciences, Colorado State University, 307 University Ave, 11
Fort Collins, CO 80523 12
13
Corresponding author: Punya Nachappa; E-mail: punya.nachappa@colostate.edu 14
Keywords: wheat curl mite, wheat streak mosaic virus, triticum mosaic virus, High 15
Plains wheat mosaic virus, resistance, virome 16
Funding: Colorado Wheat Research Foundation, Colorado Wheat Administrative 17
Committee 18
19
.CC-BY-ND 4.0 International licenseavailable under a
(which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made
The copyright holder for this preprintthis version posted August 10, 2020. ; https://doi.org/10.1101/2020.08.10.244806doi: bioRxiv preprint
2
Abstract 20
The wheat curl mite (WCM)-transmissible wheat streak disease complex is the most serious 21
disease of wheat in the U.S. Great Plains. In the current study, we determined the genetic 22
variability in WCM and mite-transmitted viruses in Colorado and identified sources of resistance 23
in Colorado wheat germplasm to wheat streak disease complex. We identified two distinct 24
genotypes of WCM, Type 1 and Type 2 based on the ribosomal ITS1 region. Both genotypes 25
were found to co-exist throughout the wheat producing regions of Colorado. Analysis of the 26
whole genome and partial coat protein sequences revealed rich diversity of wheat streak mosaic 27
virus (WSMV) and High Plains wheat mosaic virus (HPWMoV) isolates collected from 28
Colorado, whereas triticum mosaic virus (TriMV) showed low sequence variability. Analysis of 29
WSMV isolates revealed two novel isolates and one that was 100% similar to a new variant of 30
WSMV from Kansas. Interestingly, between 2-4 genotypes of all 8 RNA segments of HPWMoV 31
were identified, which suggests new variants of emaraviruses and co-occurrence of multiple 32
strains within host populations. Several novel viruses including mycoviruses were identified for 33
the first time in Colorado. We found variation in WSMV resistance among wheat varieties; 34
however a variety that harbored dual resistance to mite and WSMV had lower virus titer 35
compared to varieties that contained single resistance gene. This suggests that pyramiding genes 36
will ensure improved and durable resistance. Future research may be aimed at elucidating the 37
dynamics, diversity, and distribution of the new WSMV and HPWMoV isolates and their 38
responses to wheat genotypes. 39
40
Keywords: wheat curl mite, wheat streak mosaic virus, triticum mosaic virus, high plains wheat 41
mosaic virus, resistance, virome42
.CC-BY-ND 4.0 International licenseavailable under a
(which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made
The copyright holder for this preprintthis version posted August 10, 2020. ; https://doi.org/10.1101/2020.08.10.244806doi: bioRxiv preprint
3
Wheat (Triticum aestivum L.) is considered the most important crop in the 21
st
century as it 43
serves as a nutritional source of calories and protein in the human diet worldwide (Arzani and 44
Ashraf 2017; Curtis and Halford 2014). In the United States, wheat ranks third among field 45
crops in planted acreage, production, and gross farm receipts, behind corn and soybeans (USDA-46
ERS 2019). Among the top 10 wheat growing states, Colorado ranked 6
th
in 2019 with 2,150,000 47
acres being planted and a yield of 49 bushels per acre resulting in total production of 98,000,000 48
bushels valued at $387,100,000 (USDA-NASS 2019). The wheat curl mite (WCM), Aceria 49
tosichella Keifer (Acari: Eriophyidae) is a globally important pest affecting wheat production in 50
the Americas, Europe, and Asia (Skoracka et al. 2018). The mite causes direct damage by 51
feeding, which can reduce cereal yield (Harvey et al. 2000). But more importantly, WCM-52
transmitted viruses including wheat streak mosaic virus (family Potyviridae/genus Tritimovirus; 53
acronym WSMV) (Slykhuis 1955), triticum mosaic virus (Potyviridae/Poacevirus; TriMV) 54
(Seifers et al. 2009) and High plains wheat mosaic virus (Fimoviridae/Emaravirus; HPWMoV) 55
(Seifers et al. 1997) are among the most significant viruses in U.S. agriculture, responsible for 56
yield losses in wheat, barley, oats and rye (Burrows et al. 2009; Navia et al. 2013). Average 57
yield losses from the WCM-WSMV complex range from 5 to 7% in the US Great Plains, but 58
100% yield losses may occur in some fields (Appel et al. 2015). 59
Worldwide, the WCM has been found to be a diverse species complex with numerous 60
genetic lineages (Skoracka et al. 2018). In North America however, only two genetically distinct 61
genotypes of WCM have been characterized based on ribosomal ITS1 and mitochondrial 62
Cytochrome oxidase I/II partial sequences: Type 1, initially identified from South Dakota, 63
Kansas, Montana, Nebraska and Texas, and Type 2, from Nebraska (Hein et al. 2012). Both 64
genotypes occur in mixed populations in wheat-producing areas of the U.S. Great Plains. The 65
.CC-BY-ND 4.0 International licenseavailable under a
(which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made
The copyright holder for this preprintthis version posted August 10, 2020. ; https://doi.org/10.1101/2020.08.10.244806doi: bioRxiv preprint
4
two distinct genotypes demonstrate different responses to curl mite colonization (Cmc) genes; 66
Cmc1, Cmc2, Cmc3 and Cmc4 (Dhakal et al. 2017; Harvey et al. 1999) and differential viral 67
transmission efficiencies (Hein et al. 2012; McMechan et al. 2014; Seifers et al. 2002; Wosula 68
et al. 2016). For example, Type 2 is more virulent and makes wheat lines carrying the 1AL.1RS 69
(Cmc3 resistance gene) susceptible (Dhakal et al., 2017) and Type 2 mites transmit WSMV at 70
higher rates compared to Type 1 mites (Wosula et al., 2016). 71
The WSMV populations are complex as well with numerous genotypes (Robinson and 72
Murray 2013; Schubert et al. 2015), although different genotypes rarely occur in the same plant 73
(McNeil et al. 1996). In the U.S., there are two WSMV isolates, Sidney 81 and Type, sharing 74
97.6% nucleotide sequence identity, and produce similar symptoms in wheat (Choi et al. 2001; 75
Hall et al. 2001). A third isolate, El Batán, from Mexico has diverged from the American strains 76
and has 79% nucleotide sequence identity to Sidney 81 and Type (Choi et al. 2001). In contrast, 77
TriMV field populations showed minimal amounts of sequence variation suggesting that the 78
populations are very homogenous (Fuentes-Bueno et al. 2011). There is little information about 79
the phylogenetic relationships between HPWMoV isolates. There appears to be two distinct 80
groups of HPWMoV isolates within the U.S. (Stewart 2016). Currently there are three sources of 81
host resistance to WSMV - Wsm1, Wsm2, and Wsm3 (Liu et al. 2011; Lu et al. 2011; Triebe et 82
al. 1991). However, some of these resistance alleles are temperature sensitive and do not prevent 83
virus infection and replication above 18°C (Fahim et al. 2012). More recently, a novel QTL was 84
identified on wheat chromosome 6DS from the wheat cultivar, TAM112, which provides WCM 85
resistance and moderate WSMV resistance (Dhakal et al. 2018). Genes for resistance to TriMV 86
and HPWMoV have not been identified. 87
.CC-BY-ND 4.0 International licenseavailable under a
(which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made
The copyright holder for this preprintthis version posted August 10, 2020. ; https://doi.org/10.1101/2020.08.10.244806doi: bioRxiv preprint
5
One of the most effective ways of controlling WCM-virus complex is by planting mite 88
and disease resistant varieties; however, knowledge of mite and virus genotypes occurring in a 89
given area is critical because these genetic differences correspond to biological responses at the 90
phenotypic level (Hein et al. 2012). While Colorado is a major wheat producing state, there is no 91
information about the WCM-virus complex in the region. Moreover, little is known about 92
emerging and/or novel viruses of wheat in Colorado. Next generation sequencing is a powerful 93
tool that allows researchers to detect and characterize novel viruses (and bacterial and fungal 94
pathogens) and explore their diversity and pathogenicity in agricultural crops (Villamor et al. 95
2019). NGS is finding increased applications in revealing the viromes that contribute to the 96
disease phenotype. The term “virome” is defined as the genomes of all the viruses inhabiting a 97
specific organism or environment. In the current study, we determined the genetic variability in 98
WCM and mite-transmitted viruses in Colorado and identified sources of resistance in Colorado 99
wheat germplasm to WSMV and TriMV. In addition, we investigated the viromes of wheat from 100
four different locations in Colorado. To our knowledge, our study is among the first to report on 101
the wheat virome in the U.S. 102
103
Materials and Methods 104
Wheat Curl Mite and Plant Tissue Collection 105
Symptomatic wheat leaf tissues were collected across eastern Colorado by researchers, extension 106
agents and producers and delivered to our laboratory at Colorado State University. Plants were 107
examined using a dissecting microscope for the presence of WCMs. If present, mites were 108
transferred to healthy wheat plants of susceptible wheat varieties, Pronghorn or Hatcher at the 109
four-leaf stage or older. Plants were grown in gallon pots with 2-3 plants per pot in Promix HP
©
110
.CC-BY-ND 4.0 International licenseavailable under a
(which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made
The copyright holder for this preprintthis version posted August 10, 2020. ; https://doi.org/10.1101/2020.08.10.244806doi: bioRxiv preprint
Citations
More filters
SPAdes, a new genome assembly algorithm and its applications to single-cell sequencing ( 7th Annual SFAF Meeting, 2012)

[...]

Glenn Tesler
01 Jun 2012
TL;DR: SPAdes as mentioned in this paper is a new assembler for both single-cell and standard (multicell) assembly, and demonstrate that it improves on the recently released E+V-SC assembler and on popular assemblers Velvet and SoapDeNovo (for multicell data).
Abstract: The lion's share of bacteria in various environments cannot be cloned in the laboratory and thus cannot be sequenced using existing technologies. A major goal of single-cell genomics is to complement gene-centric metagenomic data with whole-genome assemblies of uncultivated organisms. Assembly of single-cell data is challenging because of highly non-uniform read coverage as well as elevated levels of sequencing errors and chimeric reads. We describe SPAdes, a new assembler for both single-cell and standard (multicell) assembly, and demonstrate that it improves on the recently released E+V-SC assembler (specialized for single-cell data) and on popular assemblers Velvet and SoapDeNovo (for multicell data). SPAdes generates single-cell assemblies, providing information about genomes of uncultivatable bacteria that vastly exceeds what may be obtained via traditional metagenomics studies. SPAdes is available online ( http://bioinf.spbau.ru/spades ). It is distributed as open source software.

10,124 citations

The Interface Between Wheat andthe Wheat Curl Mite, Aceriatosichella , the Primary Vector ofGlobally Important Viral Diseases

[...]

Anna Skoracka, Brian G. Rector, Gary L. Hein
01 Jan 2018
TL;DR: This report integrates the current state of knowledge of WCM–virus-plant interactions and addresses knowledge gaps regarding the mechanisms driving WCM infestation, viral epidemics, and plant responses.
Abstract: Wheat production and sustainability are steadily threatened by pests and pathogens in both wealthy and developing countries. This review is focused on the wheat curl mite (WCM), Aceria tosichella, and its relationship with wheat. WCM is a major pest of wheat and other cereals and a vector of at least four damaging plant viruses (Wheat streak mosaic virus, High plains wheat mosaic virus, Brome streak mosaic virus, and Triticum mosaic virus). The WCM–virus pathosystem causes considerable yield losses worldwide and its severity increases significantly when mixed-virus infections occur. Chemical control strategies are largely ineffective because WCM occupies secluded niches on the plant, e.g., leaf sheaths or curled leaves in the whorl. The challenge of effectively managing this pest–virus complex is exacerbated by the existence of divergent WCM lineages that differ in host-colonization and virus-transmission abilities. We highlight research progress in mite ecology and virus epidemiology that affect management and development of cereal cultivars with WCM- and virus-resistance genes. We also address the challenge of avoiding both agronomically deleterious side effects and selection for field populations of WCM that can overcome these resistance genes. This report integrates the current state of knowledge of WCM–virus-plant interactions and addresses knowledge gaps regarding the mechanisms driving WCM infestation, viral epidemics, and plant responses. We discuss the potential application of molecular methods (e.g., transcriptomics, epigenetics, and whole-genome sequencing) to understand the chemical and cellular interface between the wheat plant and WCM–virus complexes.

12 citations

Journal Article•DOI•
Resistance to the wheat curl mite and mite-transmitted viruses: challenges and future directions

[...]

Punya Nachappa1, Scott D. Haley1, Stephen Pearce1•
Colorado State University1
01 Jun 2021-Current opinion in insect science
TL;DR: Genome sequencing will be critical to fully characterize the genetic diversity in WCM and WSMV populations to better understand the occurrence of WCM-transmitted viruses and to evaluate the potential stability of resistance genes.
Abstract: Wheat curl mite (WCM) is the only known arthropod vector of four wheat viruses, the most important of which is Wheat streak mosaic virus (WSMV). Host resistance to WCM and WSMV is limited to a small number of loci, most of which are introgressed from wild relatives and are often associated with linkage drag and temperature sensitivity. Reports of virulent WCM populations and potential resistance-breaking WSMV isolates highlight the need for more diverse sources of resistance. Genome sequencing will be critical to fully characterize the genetic diversity in WCM and WSMV populations to better understand the incidence of WCM-transmitted viruses and to evaluate the potential stability of resistance genes. Characterizing host resistance genes will help build a mechanistic understanding of wheat-WCM-WSMV interactions and inform strategies to identify and engineer more durable resistance sources.

6 citations

Journal Article•DOI•
Identification of a Novel Quinvirus in the Family Betaflexiviridae That Infects Winter Wheat

[...]

Hideki Kondo1, Naoto Yoshida, Miki Fujita1, Kazuyuki Maruyama1, Kiwamu Hyodo1, Hiroshi Hisano1, Tetsuo Tamada1, Ida Bagus Andika2, Nobuhiro Suzuki1 •
Okayama University1, Qingdao Agricultural University2
19 Aug 2021-Frontiers in Microbiology
TL;DR: Analysis of de novo RNA sequencing of symptomatic and asymptomatic wheat-leaf samples obtained from a field in Hokkaido, Japan, revealed the infection by a novel betaflexivirus, which is tentatively named wheat virus Q (WVQ), together with wheat yellow mosaic virus (WYMV, a bymovirus) and northern cereal mosaicirus (a cytorhabdovirus).
Abstract: Yellow mosaic disease in winter wheat is usually attributed to the infection by bymoviruses or furoviruses; however, there is still limited information on whether other viral agents are also associated with this disease. To investigate the wheat viromes associated with yellow mosaic disease, we carried out de novo RNA sequencing (RNA-seq) analyses of symptomatic and asymptomatic wheat-leaf samples obtained from a field in Hokkaido, Japan, in 2018 and 2019. The analyses revealed the infection by a novel betaflexivirus, which tentatively named wheat virus Q (WVQ), together with wheat yellow mosaic virus (WYMV, a bymovirus) and northern cereal mosaic virus (a cytorhabdovirus). Basic local alignment search tool (BLAST) analyses showed that the WVQ strains (of which there are at least three) were related to the members of the genus Foveavirus in the subfamily Quinvirinae (family Betaflexiviridae). In the phylogenetic tree, they form a clade distant from that of the foveaviruses, suggesting that WVQ is a member of a novel genus in the Quinvirinae. Laboratory tests confirmed that WVQ, like WYMV, is potentially transmitted through the soil to wheat plants. WVQ was also found to infect rye plants grown in the same field. Moreover, WVQ-derived small interfering RNAs accumulated in the infected wheat plants, indicating that WVQ infection induces antiviral RNA silencing responses. Given its common coexistence with WYMV, the impact of WVQ infection on yellow mosaic disease in the field warrants detailed investigation.

3 citations

References
More filters
Journal Article•DOI•
Viruses of plant pathogenic fungi.

[...]

Said A. Ghabrial1, Nobuhiro Suzuki•
University of Kentucky1
03 Aug 2009-Annual Review of Phytopathology
TL;DR: Select mycoviruses that cause debilitating diseases and/or reduce the virulence of their phytopathogenic fungal hosts are discussed and such fungal-virus systems are valuable for the development of novel biocontol strategies and for gaining an insight into the molecular basis of fungal virulence.
Abstract: Mycoviruses are widespread in all major groups of plant pathogenic fungi. They are transmitted intracellularly during cell division, sporogenesis, and cell fusion, but apparently lack an extracellular route for infection. Their natural host ranges are limited to individuals within the same or closely related vegetative compatibility groups. Recent advances, however, allowed the establishment of experimental host ranges for a few mycoviruses. Although the majority of known mycoviruses have dsRNA genomes that are packaged in isometric particles, an increasing number of usually unencapsidated mycoviruses with positive-strand RNA genomes have been reported. We discuss selected mycoviruses that cause debilitating diseases and/or reduce the virulence of their phytopathogenic fungal hosts. Such fungal-virus systems are valuable for the development of novel biocontol strategies and for gaining an insight into the molecular basis of fungal virulence. The availability of viral and host genome sequences and of transformation and transfection protocols for some plant pathogenic fungi will contribute to progress in fungal virology.

496 citations

"Ecology and Epidemiology of Wheat C..." refers background in this paper

  • ...Most mycoviruses do not cause any morphological changes in their fungal hosts (Ghabrial and Suzuki 2009; Wang et al. 2013)....

    [...]

Journal Article•DOI•
Hypovirulence: Mycoviruses at the fungal–plant interface

[...]

Donald L. Nuss1•
University of Maryland Biotechnology Institute1
01 Aug 2005-Nature Reviews Microbiology
TL;DR: The recent development of an infectious cDNA-based reverse genetics system for members of the Hypoviridae mycovirus family has enabled the analysis of basic aspects of this fascinating virus–fungus–plant interaction, including virus–host interactions, the mechanisms underlying fungal pathogenesis, fungal signalling pathways and the evolution of RNA silencing.
Abstract: Whereas most mycoviruses lead 'secret lives', some reduce the ability of their fungal hosts to cause disease in plants. This property, known as hypovirulence, has attracted attention owing to the importance of fungal diseases in agriculture and the limited strategies that are available for the control of these diseases. Using one pathogen to control another is appealing, both intellectually and ecologically. The recent development of an infectious cDNA-based reverse genetics system for members of the Hypoviridae mycovirus family has enabled the analysis of basic aspects of this fascinating virus–fungus–plant interaction, including virus–host interactions, the mechanisms underlying fungal pathogenesis, fungal signalling pathways and the evolution of RNA silencing. Such systems also provide a means for engineering mycoviruses for enhanced biocontrol potential.

461 citations

"Ecology and Epidemiology of Wheat C..." refers background in this paper

  • ...(Dawe and Nuss 2013; Nuss 2005; Pearson et al. 2009)....

    [...]

  • ...This suggests mycoviruses could be a promising biocontrol agent for combating fungal diseases (Nuss 2005)....

    [...]

Journal Article•DOI•
Mycoviruses of filamentous fungi and their relevance to plant pathology

[...]

Michael N. Pearson1, Ross E. Beever2, B. Boine1, K. Arthur1•
University of Auckland1, Landcare Research2
01 Jan 2009-Molecular Plant Pathology
TL;DR: Two hypotheses for the origin of mycoviruses of plant pathogens are discussed: the first that they are of unknown but ancient origin and have coevolved along with their hosts, and the second that they have relatively recently moved from a fungal plant host into the fungus.
Abstract: Mycoviruses (fungal viruses) are reviewed with emphasis on plant pathogenic fungi. Based on the presence of virus-like particles and unencapsidated dsRNAs, mycoviruses are common in all major fungal groups. Over 80 mycovirus species have been officially recognized from ten virus families, but a paucity of nucleic acid sequence data makes assignment of many reported mycoviruses difficult. Although most of the particle types recognized to date are isometric, a variety of morphologies have been found and, additionally, many apparently unencapsidated dsRNAs have been reported. Until recently, most characterized mycoviruses have dsRNA genomes, but ssRNA mycoviruses now constitute about one-third of the total. Two hypotheses for the origin of mycoviruses of plant pathogens are discussed: the first that they are of unknown but ancient origin and have coevolved along with their hosts, the second that they have relatively recently moved from a fungal plant host into the fungus. Although mycoviruses are typically readily transmitted through asexual spores, transmission through sexual spores varies with the host fungus. Evidence for natural horizontal transmission has been found. Typically, mycoviruses are apparently symptomless (cryptic) but beneficial effects on the host fungus have been reported. Of more practical interest to plant pathologists are those viruses that confer a hypovirulent phenotype, and the scope for using such viruses as biocontrol agents is reviewed. New tools are being developed based on host genome studies that will help to address the intellectual challenge of understanding the fungal-virus interactions and the practical challenge of manipulating this relationship to develop novel biocontrol agents for important plant pathogens.

410 citations

Journal Article•DOI•
Food security: the challenge of increasing wheat yield and the importance of not compromising food safety.

[...]

Tanya Y. Curtis1, Nigel G. Halford1•
Rothamsted Research1
01 May 2014-Annals of Applied Biology
TL;DR: Wheat yield must be increased while not compromising food safety, and the emerging problem of processing contaminants is reviewed, focussing in particular on acrylamide, a contaminant that forms from free asparagine and reducing sugars during high temperature cooking and processing.
Abstract: Current wheat yield and consumption is considered in the context of the historical development of wheat, from early domestication through to modern plant breeding, the Green Revolution and wheat's place as one of the world's most productive and important crops in the 21st Century. The need for further improvement in the yield potential of wheat in order to meet current and impending challenges is discussed, including rising consumption and the demand for grain for fuel as well as food. Research on the complex genetics underlying wheat yield is described, including the identification of quantitative trait loci and individual genes, and the prospects of biotechnology playing a role in wheat improvement in the future are discussed. The challenge of preparing wheat to meet the problems of drought, high temperature and increasing carbon dioxide concentration that are anticipated to come about as a result of climate change is also reviewed. Wheat yield must be increased while not compromising food safety, and the emerging problem of processing contaminants is reviewed, focussing in particular on acrylamide, a contaminant that forms from free asparagine and reducing sugars during high temperature cooking and processing. Wheat breeders are strongly encouraged to consider the contaminant issue when breeding for yield.

287 citations

Journal Article•
Aceria tulipae Keifer (Acarina: Eriophyidae) in Relation to the Spread of Wheat Streak Mosaic.

[...]

J. T. Slykhuis
01 Jan 1955-Phytopathology

199 citations

Related Papers (5)
Differential Transmission of Two Isolates of Wheat streak mosaic virus by Five Wheat Curl Mite Populations

[...]

01 Jan 2016-Plant Disease
Everlyne N. Wosula, Anthony J. McMechan, C. Oliveira-Hofman, Stephen N. Wegulo, Gary L. Hein 
Wheat Virus Identification Within Infected Tissue Using Nanopore Sequencing Technology

[...]

19 Jul 2019-Plant Disease
John P. Fellers, Christian Webb, Madison C Fellers, Jessica L. Shoup Rupp, Erick D. De Wolf 
First Report of Wheat streak mosaic virus on Wheat in New Zealand.

[...]

09 Mar 2009-Plant Disease
B. S. M. Lebas, Francisco M. Ochoa-Corona, B. J. R. Alexander, R. A. Lister, J. D. Fletcher, S. L. Bithell, G. M. Burnip 
Variations in coat protein sequence of Wheat streak mosaic virus among crop and non-crop hosts

[...]

08 May 2017-Crop & Pasture Science
Khushwant Singh, Jiban Kumar Kundu
Phylogenetic relationships, strain diversity and biogeography of tritimoviruses

[...]

01 Apr 2002-Journal of General Virology
Frank Rabenstein, Dallas L. Seifers, Jorg Schubert, Roy French, Drake C. Stenger