scholarly journals Cloning and sequence analysis of an infectious clone of Citrus yellow mosaic virus that can infect sweet orange via Agrobacterium-mediated inoculation

2001 ◽  
Vol 82 (10) ◽  
pp. 2549-2558 ◽  
Author(s):  
Qi Huang ◽  
John S. Hartung

Citrus yellow mosaic virus (CYMV), a member of the family Caulimoviridae, genus Badnavirus, causes citrus mosaic disease, a disease that occurs commonly in India. The CYMV genome has been cloned and its complete nucleotide sequence determined. Its DNA genome is 7559 bp in length and contains six putative open reading frames (ORFs), all on the plus-strand of the genome and each capable of encoding proteins with a molecular mass of greater than 10 kDa. ORF 3, the largest ORF, encodes a putative polyprotein for functions involved in virus movement, assembly and replication. The other ORFs encode proteins whose exact functions are not completely understood. The genome also contains a plant tRNAmet-binding site, which may serve as a primer for minus-strand DNA synthesis, in its intergenic region. Phylogenetic analysis of the badnaviruses revealed that CYMV is most closely related to Cacao swollen shoot virus. It was demonstrated that a construct containing 1·4 copies of the cloned CYMV genome could infect sweet orange via Agrobacterium-mediated inoculation.

Agronomy ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 622 ◽  
Author(s):  
Chandra Mohan Singh ◽  
Poornima Singh ◽  
Aditya Pratap ◽  
Rakesh Pandey ◽  
Shalini Purwar ◽  
...  

Yellow mosaic disease (YMD) affects several types of leguminous crops, including the Vigna species, which comprises a number of commercially important pulse crops. YMD is characterized by the formation of a bright yellow mosaic pattern on the leaves; in severe forms, this pattern can also be seen on stems and pods. This disease leads to tremendous yield losses, even up to 100%, in addition to deterioration in seed quality. Symptoms of this disease are similar among affected plants; YMD is not limited to mungbean (Vigna radiata L. Wilczek) and also affects other collateral and alternate hosts. In the last decade, rapid advancements in molecular detection techniques have been made, leading to an improved understanding of YMD-causing viruses. Three distinct bipartite begomoviruses, namely, Mungbean Yellow Mosaic India Virus (MYMIV), Mungbean Yellow Mosaic Virus (MYMV), and Horsegram Yellow Mosaic Virus (HgYMV), are known to cause YMD in Vigna spp. Vigna crops serve as an excellent protein source for vegetarians worldwide; moreover, they aid in improving soil health by fixing atmospheric nitrogen through a symbiotic association with Rhizobium bacteria. The loss in the yield of these short-duration crops due to YMD, thus, needs to be checked. This review highlights the discoveries that have been made regarding various aspects of YMD affecting mungbean, including the determination of YMD-causing viruses and strategies used to develop high-yielding YMD-resistant mungbean varieties that harness the potential of related Vigna species through the use of different omics approaches.


2002 ◽  
Vol 76 (7) ◽  
pp. 3382-3387 ◽  
Author(s):  
Marilyn J. Roossinck

ABSTRACT Cucumber mosaic virus (CMV) is an RNA plant virus with a tripartite genome and an extremely broad host range. Previous evolutionary analyses with the coat protein (CP) and 5′ nontranslated region (NTR) of RNA 3 suggested subdivision of the virus into three groups, subgroups IA, IB, and II. In this study 15 strains of CMV whose nucleotide sequences have been determined were used for a complete phylogenetic analysis of the virus. The trees estimated for open reading frames (ORFs) located on the different RNAs were not congruent and did not completely support the subgrouping indicated by the CP ORF, indicating that different RNAs had independent evolutionary histories. This is consistent with a reassortment mechanism playing an important role in the evolution of the virus. The evolutionary trees of the 1a and 3a ORFs were more compact and displayed more branching than did those of the 2a and CP ORFs. This may reflect more rigid host-interactive constraints exerted on the 1a and 3a ORFs. In addition, analysis of the 3′ NTR that is conserved among all RNAs indicated that evolutionary constraints on this region are specific to the RNA component rather than the virus isolate. This indicates that functions other than replication are encoded in the 3′ NTR. Reassortment may have led to the genetic diversity found among CMV strains and contributed to its enormous evolutionary success.


Author(s):  
Sudeep Pandey ◽  
T.R. Girish ◽  
S. Basavaraj ◽  
A.S. Padmaja ◽  
N. Nagaraju

Background: Yellow mosaic disease (YMD) caused by begomoviruses transmitted through the insect vector Bemisia tabaci poses a serious threat to the production of legume crops. Methods: Season-long surveys were carried out for YMD occurrence in six different legume crops and associated natural weeds both symptomatic and asymptomatic across the districts of southern Karnataka, India. The samples were analyzed through RCA PCR using specific primer pairs. Result: Up to 94.1 per cent YMD incidence was recorded and nine weed species were commonly found associated with legume crops. The weeds viz., Ageratum conyzoides, Alternanthera sessilis, Commelina benghalensis and Euphorbia geniculata were abundantly found in the surveyed regions. The weeds were both symptomatic and asymptomatic. Rolling circle amplification coupled polymerase chain reaction method was employed to detect yellow mosaic virus in asymptomatic weeds. Phylogenetic analysis based on the sequences of PCR amplified products of weeds and symptomatic legumes revealed a close clustering of the weed samples with horsegram yellow mosaic virus, legume yellow mosaic virus and mungbean yellow mosaic virus. Overall, our data suggests the role of weed species associated with legume crops as alternative/collateral hosts of begomoviruses and their role in the epidemiology of yellow mosaic disease.


2021 ◽  
Author(s):  
Yang Sun ◽  
Yan qiong Li ◽  
Wen han Dong ◽  
Ai li Sun ◽  
Ning wei Chen ◽  
...  

Abstract The complete genome of the dsRNA virus isolated from Rhizoctonia solani AG-1 IA 9–11 (designated as Rhizoctonia solani dsRNA virus 11, RsRV11 ) were determined. The RsRV11 genome was 9,555 bp in length, contained three conserved domains, SMC, PRK and RT-like super family, and encoded two non-overlapping open reading frames (ORFs). ORF1 potentially coded for a 204.12 kDa predicted protein, which shared low but significant amino acid sequence identities with the putative protein encoded by Rhizoctonia solani RNA virus HN008 (RsRV-HN008) ORF1. ORF2 potentially coded for a 132.41 kDa protein which contained the conserved motifs of the RNA-dependent RNA polymerase (RdRp). Phylogenetic analysis indicated that RsRV11 was clustered with RsRV-HN008 in a separate clade independent of other virus families. It implies that RsRV11, along with RsRV-HN008 possibly a new fungal virus taxa closed to the family Megabirnaviridae, and RsRV11 is a new member of mycoviruses.


Viruses ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 432 ◽  
Author(s):  
Fangmin Hao ◽  
Mingde Wu ◽  
Guoqing Li

Here, we characterized a negative single-stranded (−ss)RNA mycovirus, Botrytis cinerea mymonavirus 1 (BcMyV1), isolated from the phytopathogenic fungus Botrytis cinerea. The genome of BcMyV1 is 7863 nt in length, possessing three open reading frames (ORF1–3). The ORF1 encodes a large polypeptide containing a conserved mononegaviral RNA-dependent RNA polymerase (RdRp) domain showing homology to the protein L of mymonaviruses, whereas the possible functions of the remaining two ORFs are still unknown. The internal cDNA sequence (10-7829) of BcMyV1 was 97.9% identical to the full-length cDNA sequence of Sclerotinia sclerotiorum negative stranded RNA virus 7 (SsNSRV7), a virus-like contig obtained from Sclerotinia sclerotiorum metatranscriptomes, indicating BcMyV1 should be a strain of SsNSRV7. Phylogenetic analysis based on RdRp domains showed that BcMyV1 was clustered with the viruses in the family Mymonaviridae, suggesting it is a member of Mymonaviridae. BcMyV1 may be widely distributed in regions where B. cinerea occurs in China and even over the world, although it infected only 0.8% of tested B. cinerea strains.


Plant Disease ◽  
2020 ◽  
Vol 104 (10) ◽  
pp. 2713-2719 ◽  
Author(s):  
Fei Xing ◽  
Wanying Hou ◽  
Sebastien Massart ◽  
Dehang Gao ◽  
Wenhui Li ◽  
...  

Apple mosaic disease is widespread in the major apple-producing areas in China and is frequently associated with the presence of the newly identified Apple necrotic mosaic virus (ApNMV), belonging to subgroup 3 of Ilarvirus genus in the family of Bromoviridae. Mosaic symptoms were also observed in a hawthorn tree. Deep sequencing revealed the hawthorn tree with mosaic symptom was infected by ApNMV, which was confirmed by RT-PCR. The complete nucleotide sequences of RNA1 (3,378 nt), RNA2 (2,778 nt), and RNA3 (1,917 nt) of ApNMV from the hawthorn were obtained, sharing 93.8 to 96.8%, 89.7 to 96.1%, and 89.8 to 94.6% nucleotide identities with those from apples and crabapples, respectively. Two hypervariable regions were found, which showed 59.2 to 85.7% and 64.0 to 89.3% sequence identities at position 142 to 198 aa and at position 780 to 864 aa in the POL protein, respectively, between the hawthorn isolate and other isolates (apple, crabapple). A grafting test demonstrated that ApNMV was easily transmissible from hawthorns to apple trees, with severe chlorosis, yellowing, mosaic, curling, and necrosis. In addition, a total of 11,685 hawthorn trees were surveyed for the incidence of mosaic disease from five provinces in China, and only six were found showing typical mosaic symptoms. A total of 145 individual trees (six symptomatic, 68 asymptomatic, and 71 other symptoms) were tested for the presence or absence of ApNMV by RT-PCR. Among them, six symptomatic, four asymptomatic, and 10 other symptomatic trees tested positive for ApNMV. Taken together, these results demonstrated that the hawthorn tree was identified as a new natural host for ApNMV with a relatively low frequency (13.8%, 20 out of 145) in the main producing areas, and it was likely to be the causal pathogen of hawthorn mosaic disease.


Author(s):  
Hélène Pidon ◽  
Neele Wendler ◽  
Antje Habekuβ ◽  
Anja Maasberg ◽  
Brigitte Ruge-Wehling ◽  
...  

Abstract Key message We mapped the Rym14Hb resistance locus to barley yellow mosaic disease in a 2Mbp interval. The co-segregating markers will be instrumental for marker-assisted selection in barley breeding. Abstract Barley yellow mosaic disease is caused by Barley yellow mosaic virus and Barley mild mosaic virus and leads to severe yield losses in barley (Hordeum vulgare) in Central Europe and East-Asia. Several resistance loci are used in barley breeding. However, cases of resistance-breaking viral strains are known, raising concerns about the durability of those genes. Rym14Hb is a dominant major resistance gene on chromosome 6HS, originating from barley’s secondary genepool wild relative Hordeum bulbosum. As such, the resistance mechanism may represent a case of non-host resistance, which could enhance its durability. A susceptible barley variety and a resistant H. bulbosum introgression line were crossed to produce a large F2 mapping population (n = 7500), to compensate for a ten-fold reduction in recombination rate compared to intraspecific barley crosses. After high-throughput genotyping, the Rym14Hb locus was assigned to a 2Mbp telomeric interval on chromosome 6HS. The co-segregating markers developed in this study can be used for marker-assisted introgression of this locus into barley elite germplasm with a minimum of linkage drag.


2017 ◽  
Vol 5 (37) ◽  
Author(s):  
Yeonhwa Jo ◽  
Myung-Kyu Song ◽  
Hoseong Choi ◽  
Jae-Seong Park ◽  
Jae-Wung Lee ◽  
...  

ABSTRACT Here, we report the genome sequence of grapevine virus T (GVT), a novel single-stranded RNA virus identified from a transcriptome of grapevine. The genome of GVT is 8,701 nucleotides in length and encodes five open reading frames. GVT is a putative member of the genus Foveavirus in the family Betaflexiviridae.


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