scholarly journals Defective RNA of a Novel Mycovirus with High Transmissibility Detrimental to Biocontrol Properties of Trichoderma spp.

2019 ◽  
Vol 7 (11) ◽  
pp. 507 ◽  
Author(s):  
Jiaqi You ◽  
Kang Zhou ◽  
Xiaolin Liu ◽  
Mingde Wu ◽  
Long Yang ◽  
...  

Trichoderma species are a group of fungi which is widely distributed in major terrestrial ecosystems; they are also commonly used as biocontrol agents for many plant diseases. A virus, namely Trichoderma harzianum hypovirus 1 (ThHV1), was identified in T. harzianum isolate T-70, and also infected isolate T-70D, together with its defective RNA (ThHV1-S). The ThHV1 genome possessed two Open Reading Frames (ORFs), namely ORF1 and ORF2. The start codon of ORF2 overlapped with the stop codon of ORF1 in a 43 nt long region. The polypeptide encoded by ORF2 of ThHV1 shared sequence similarities with those of betahypoviruses, indicating that ThHV1 is a novel member of Hypoviridea. Isolate T-70D, carrying both ThHV1 and ThHV1-S, showed abnormal biological properties, notably a decreased mycoparasitism ability when compared with isolate T-70. Both ThHV1 and ThHV1-S could be vertically transmitted to conidia and horizontally transmitted to T. harzianum isolate T-68 and T. koningiopsis T-51. The derivative strains carrying both ThHV1 and ThHV1-S showed decreased mycoparasitism ability, whereas strains carrying ThHV1 alone were normal, indicating that ThHV1-S is closely associated with the decreased mycoparasitism ability of T. harzianum isolate T-70D. ThHV1 was widely detected in isolates of T. harzianum, T. koningiopsis and T. atroviride originating from soil of China. Therefore, viruses in fungal biocontrol agents may also be a factor associated with the stability of their application.

2021 ◽  
Author(s):  
Yating Liu ◽  
Joseph Dougherty

Whole genome sequencing of patient populations is identifying thousands of new variants in UnTranslated Regions(UTRs). While the consequences of UTR mutations are not as easily predicted from primary sequence as coding mutations are, there are some known features of UTRs modulate their function. utR.annotation is an R package that can be used to annotate potential deleterious variants in the UTR regions for both human and mouse species. Given a CSV or VCF format variant file, utR.annotation provides information of each variant on whether and how it alters known translational regulators including:upstream Open Reading Frames (uORFs), upstream Kozak sequences, polyA signals, the Kozak sequence at the annotated translation initiation site, start codon, and stop codon, conservation scores in the variant position, and whether and how it changes ribosome loading based on a model from empirical data.


2019 ◽  
Vol 7 (3) ◽  
pp. 309-316 ◽  
Author(s):  
Nabin Pandey ◽  
Madhusudhan Adhikhari ◽  
Binod Bhantana

In the world, the traditional agricultural practices are getting affected by various problems such as disease, pest, drought, decreased soil fertility due to use of hazardous chemical pesticides, pollution and global warming. As a result, there is a need for some eco-friendly bio-control agents that help in resolving the previous mentioned problems. The various types of biological control agents such as bacteria and fungi are involved in bio-control activity. Among them, fungal genus Trichoderma plays a major role in controlling the plant diseases. Species of Trichoderma are diverse fungal microbial community known and explored worldwide for their versatilities as biocontrol and growth promoting agents. These fungi reproduce asexually by production of conidia and chlamydospores and in wild habitats by ascospores. Trichoderma species are efficient mycoparasites and prolific producers of secondary metabolites, some of which have clinical importance. However, the ecological or biological significance of this metabolite diversity is sorely lagging behind the chemical significance. Several Trichoderma spp. positively affect plants by stimulating plant growth, and protecting plants from fungal and bacterial pathogens. They are used in biological plant protection as bio-fungicides as well as in bioremediation. A large number of research groups are working on various aspects of Trichoderma viz., diversity, ecology and their applications. The capacity of Trichoderma fungi to produce lytic enzymes is used in animal feed, and wine making and brewery industries. Trichoderma spp. are the most successful bio-control agents as more than 60% of the registered bio-fungicides used in today’s agriculture belongs to Trichoderma -based formulation. The increase in incidence and severity of diseases and emergence of new diseases causes the significant yield losses of different crops in Nepal. But the research and studies on plant diseases are limited. Int. J. Appl. Sci. Biotechnol. Vol 7(3): 309-316  


Viruses ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 83 ◽  
Author(s):  
Hong Liu ◽  
Rui Liu ◽  
Chang Li ◽  
Hui Wang ◽  
Hong Zhu ◽  
...  

Three dsRNAs, in sizes of approximately 2.5–5 kbp, were detected in the plant pathogenic fungus Nigrospora oryzae strain CS-7.5-4. Genomic analysis showed that the 5.0 kb dsRNA was a victorivirus named as Nigrospora oryzae victorivirus 2 (NoRV2). The genome of NoRV2 was 5166 bp in length containing two overlapping open reading frames (ORFs), ORF1 and ORF2. ORF1 was deduced to encode a coat protein (CP) showing homology to the CPs of viruses belonging to the Totiviridae family. The stop codon of ORF1 and the start codon of ORF2 were overlapped by the tetranucleotide sequence AUGA. ORF2 was predicted to encode an RNA-dependent RNA polymerase (RdRp), which was highly similar to the RdRps of victoriviruses. Virus-like particle examination demonstrated that the genome of NoRV2 was solely encapsidated by viral particles with a diameter of approximately 35 nm. The other two dsRNAs that were less than 3.0 kb were predicted to be the genomes of two mitoviruses, named as Nigrospora oryzae mitovirus 1 (NoMV1) and Nigrospora oryzae mitovirus 2 (NoMV2). Both NoMV1 and NoMV2 were A-U rich and with lengths of 2865 and 2507 bp, respectively. Mitochondrial codon usage inferred that each of the two mitoviruses contains a major large ORF encoding a mitoviral RdRp. Horizontal transfer experiments showed that the NoMV1 and NoMV2 could be cotransmitted horizontally via hyphal contact to other virus-free N. oryzae strains and causes phenotypic change to the recipient, such as an increase in growth rate. This is the first report of mitoviruses in N. oryzae.


2012 ◽  
Vol 78 (19) ◽  
pp. 7082-7089 ◽  
Author(s):  
Y. S. Lapteva ◽  
O. E. Zolova ◽  
M. G. Shlyapnikov ◽  
I. M. Tsfasman ◽  
T. A. Muranova ◽  
...  

ABSTRACTLytic enzymes are the group of hydrolases that break down structural polymers of the cell walls of various microorganisms. In this work, we determined the nucleotide sequences of theLysobactersp. strain XL1alpAandalpBgenes, which code for, respectively, secreted lytic endopeptidases L1 (AlpA) and L5 (AlpB).In silicoanalysis of their amino acid sequences showed these endopeptidases to be homologous proteins synthesized as precursors similar in structural organization: the mature enzyme sequence is preceded by an N-terminal signal peptide and a pro region. On the basis of phylogenetic analysis, endopeptidases AlpA and AlpB were assigned to the S1E family [clan PA(S)] of serine peptidases. Expression of thealpAandalpBopen reading frames (ORFs) inEscherichia coliconfirmed that they code for functionally active lytic enzymes. Each ORF was predicted to have the Shine-Dalgarno sequence located at a canonical distance from the start codon and a potential Rho-independent transcription terminator immediately after the stop codon. ThealpAandalpBmRNAs were experimentally found to be monocistronic; transcription start points were determined for both mRNAs. The synthesis of thealpAandalpBmRNAs was shown to occur predominantly in the late logarithmic growth phase. The amount ofalpAmRNA in cells ofLysobactersp. strain XL1 was much higher, which correlates with greater production of endopeptidase L1 than of L5.


2020 ◽  
Vol 8 (6) ◽  
pp. 817 ◽  
Author(s):  
Raja Asad Ali Khan ◽  
Saba Najeeb ◽  
Shaukat Hussain ◽  
Bingyan Xie ◽  
Yan Li

Phytopathogenic fungi, causing significant economic and production losses, are becoming a serious threat to global food security. Due to an increase in fungal resistance and the hazardous effects of chemical fungicides to human and environmental health, scientists are now engaged to explore alternate non-chemical and ecofriendly management strategies. The use of biocontrol agents and their secondary metabolites (SMs) is one of the potential approaches used today. Trichoderma spp. are well known biocontrol agents used globally. Many Trichoderma species are the most prominent producers of SMs with antimicrobial activity against phytopathogenic fungi. Detailed information about these secondary metabolites, when grouped together, enhances the understanding of their efficient utilization and further exploration of new bioactive compounds for the management of plant pathogenic fungi. The current literature provides the information about SMs of Trichoderma spp. in a different context. In this review, we summarize and group different antifungal SMs of Trichoderma spp. against phytopathogenic fungi along with a comprehensive overview of some aspects related to their chemistry and biosynthesis. Moreover, a brief overview of the biosynthesis pathway, action mechanism, and different approaches for the analysis of SMs and the factors affecting the regulation of SMs in Trichoderma is also discussed.


2017 ◽  
Author(s):  
Ana C Conrado ◽  
Hugo Arruda ◽  
David Stanton ◽  
Samuel W James ◽  
Peter Kille ◽  
...  

Pontoscolex corethrurus (Müller, 1857) plays an important role in soil terrestrial ecosystems and has been widely used as an animal model for a large variety of ecological studies, in particular due to its common presence and generally high abundance in human-disturbed tropical soils. In this study we describe the complete mitochondrial genome of the peregrine earthworm Pontoscolex corethrurus. This is the first record of a mitochondrial genome within the Rhinodrilidae family. Its mitochondrial genome is 14 835 bp in length containing 37 genes (13 protein-coding genes (PCG), 2 rRNA genes and 22 tRNA genes). It has the same gene content and structure as in other sequenced earthworms, but unusual among invertebrates it has several overlapping open reading frames. All genes are encoded on the same strand, most of the PCGs use ATG as the start codon except for NAD3, which uses GTG as the start codon. The T+A content of the mitochondrial genome is 59.9% (31.9% A, 27.9% T, 14.9% G, and 25.3% for C). The annotated genome sequence has been deposited in GenBank under the accession number KT988053.


2017 ◽  
Author(s):  
Ana C Conrado ◽  
Hugo Arruda ◽  
David Stanton ◽  
Samuel W James ◽  
Peter Kille ◽  
...  

Pontoscolex corethrurus (Müller, 1857) plays an important role in soil terrestrial ecosystems and has been widely used as an animal model for a large variety of ecological studies, in particular due to its common presence and generally high abundance in human-disturbed tropical soils. In this study we describe the complete mitochondrial genome of the peregrine earthworm Pontoscolex corethrurus. This is the first record of a mitochondrial genome within the Rhinodrilidae family. Its mitochondrial genome is 14 835 bp in length containing 37 genes (13 protein-coding genes (PCG), 2 rRNA genes and 22 tRNA genes). It has the same gene content and structure as in other sequenced earthworms, but unusual among invertebrates it has several overlapping open reading frames. All genes are encoded on the same strand, most of the PCGs use ATG as the start codon except for NAD3, which uses GTG as the start codon. The T+A content of the mitochondrial genome is 59.9% (31.9% A, 27.9% T, 14.9% G, and 25.3% for C). The annotated genome sequence has been deposited in GenBank under the accession number KT988053.


Author(s):  
Delano James ◽  
James Phelan ◽  
Daniel Sanderson

Blackcurrant leaf chlorosis associated virus (BCLCaV) was detected recently by next-generation sequencing (NGS) and proposed as a new and distinct species in the genus Idaeovirus. Genomic components of BCLCaV that were detected and confirmed include: 1) RNA-1 that is monocistronic and encodes the replicase complex; 2) a bicistronic RNA-2 that encodes a movement protein (MP) and the coat protein (CP) of the virus, with open reading frames (ORF) that overlap by a single adenine (A) nucleotide (nt) representing the third position of an opal stop codon of the MP ORF2a and the first position of the start codon of the CP ORF2b; 3) a subgenomic form of RNA-2 (RNA-3) that contains ORF2b; and 4) a concatenated form of RNA-2 that consists of a complementary and inverted RNA-3 conjoined to the full-length RNA-2. Analysis of NGS-derived paired-end reads revealed the existence of bridge reads encompassing the 3’-terminus and 5’-terminus of RNA-2 or RNA-3 of BCLCaV. The full RNA-2 or RNA-3 could be amplified using outward facing or abutting primers; also RNA-2/RNA-3 could be detected even after three consecutive RNase R enzyme treatments with denaturation at 95 oC preceding each digestion. Evidence was obtained indicating that there are circular forms of BCLCaV RNA-2 and RNA-3.


2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Chenchen Liu ◽  
Mei Li ◽  
Estifanos Tsegaye Redda ◽  
Jie Mei ◽  
Jiantai Zhang ◽  
...  

Abstract Background Trichoderma spp. are used extensively in agriculture as biological control agents to prevent soil-borne plant diseases. In recent years, mycoviruses from fungi have attracted increasing attention due to their effects on their hosts, but Trichoderma mycoviruses have not been the subject of extensive study. We sought to discover novel mycoviruses from Trichoderma spp. and to determine the effects of the biocontrol function of Trichoderma spp. Methods Mycoviruses were screened by dsRNA extraction and metagenomic analysis. RT-PCR, 5′ RACE, and 3′ RACE were used to obtain the genome sequence. MEGA software was used to classify the new mycovirus. The effects of the identified mycovirus on the biological properties of the host strain 525 were evaluated using cucumber plants and Fusarium oxysporum f. sp. cucumerinum. Results A novel mycovirus, Trichoderma harzianum mycovirus 1 (ThMV1) (accession number MH155602), was discovered in Trichoderma harzianum strain 525, a soil-borne fungus collected from Inner Mongolia, China. The mycovirus exhibited a double-stranded RNA (dsRNA) genome with a complete genome sequence of 3160 base pairs and two open reading frames (ORFs) on the negative strand. Phylogenetic analysis indicated that it belongs to an unclassified family of dsRNA mycoviruses. The removal of ThMV1 from the host 525 strain reduced host biomass production and improved the biocontrol capability of the host for Fusarium oxysporum f. sp. cucumerinum. At same time, the presence of ThMV1 improved the growth of cucumber. Conclusion ThMV1 is a new unclassified mycovirus found in T. harzianum. It not only affects the phenotype of the host strain but also reduces its biocontrol function, which sheds light on the interaction between the mycovirus and Trichoderma spp.


2020 ◽  
Vol 33 (8) ◽  
pp. 1036-1039 ◽  
Author(s):  
Yi Zhou ◽  
Yilian Wang ◽  
Kai Chen ◽  
Yuanzheng Wu ◽  
Jindong Hu ◽  
...  

Trichoderma species are widely used to control fungal and nematode diseases of crops. To date, only one complete Trichoderma genome has been sequenced, T. reesei QM6a, a model fungus for industrial enzyme production, while the species or strains used for biological control of plant diseases are only available as draft genomes. Previously, we demonstrated that two Trichoderma strains (T. afroharzianum and T. cyanodichotomus) provide effective control of nematode and fungal plant pathogens. Based on deep sequencing using Illumina and Pacbio platforms, we have assembled high-quality genomes of the above two strains, with contig N50 reaching 4.2 and 1.7 Mbp, respectively, which is greater than those of published draft genomes. The genome data will provide a resource to assist research on the biological control mechanisms of Trichoderma spp.


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