scholarly journals Genetic variability and evolutionary dynamics of atypical Papaya ringspot virus infecting Papaya

PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0258298
Author(s):  
Anam Saleem ◽  
Zahid Ali ◽  
Shyi-Dong Yeh ◽  
Wajeeha Saeed ◽  
Amna Binat Imdad ◽  
...  

Papaya ringspot virus biotype-P is a detrimental pathogen of economically important papaya and cucurbits worldwide. The mutation prone feature of this virus perhaps accounts for its geographical dissemination. In this study, investigations of the atypical PRSV-P strain was conducted based on phylogenetic, recombination and genetic differentiation analyses considering of it’s likely spread across India and Bangladesh. Full length genomic sequences of 38 PRSV isolates and 35 CP gene sequences were subjected to recombination analysis. A total of 61 recombination events were detected in aligned complete PRSV genome sequences. 3 events were detected in complete genome of PRSV strain PK whereas one was in its CP gene sequence. The PRSV-PK appeared to be recombinant of a major parent from Bangladesh. However, the genetic differentiation based on full length genomic sequences revealed less frequent gene flow between virus PRSV-PK and the population from America, India, Colombia, other Asian Countries and Australia. Whereas, frequent gene flow exists between Pakistan and Bangladesh virus populations. These results provided evidence correlating geographical position and genetic distances. We speculate that the genetic variations and evolutionary dynamics of this virus may challenge the resistance developed in papaya against PRSV and give rise to virus lineage because of its atypical emergence where geographic spread is already occurring.

Plant Disease ◽  
2004 ◽  
Vol 88 (5) ◽  
pp. 516-522 ◽  
Author(s):  
Gustavo Fermin ◽  
Valentina Inglessis ◽  
Cesar Garboza ◽  
Sairo Rangel ◽  
Manuel Dagert ◽  
...  

Local varieties of papaya grown in the Andean foothills of Mérida, Venezuela, were transformed independently with the coat protein (CP) gene from two different geographical Papaya ringspot virus (PRSV) isolates, designated VE and LA, via Agrobacterium tumefaciens. The CP genes of both PRSV isolates show 92 and 96% nucleotide and amino acid sequence similarity, respectively. Four PRSV-resistant R0 plants were intercrossed or selfed, and the progenies were tested for resistance against the homologous isolates VE and LA, and the heterologous isolates HA (Hawaii) and TH (Thailand) in greenhouse conditions. Resistance was affected by sequence similarity between the transgenes and the challenge viruses: resistance values were higher for plants challenged with the homologous isolates (92 to 100% similarity) than with the Hawaiian (94% similarity) and, lastly, Thailand isolates (88 to 89% similarity). Our results show that PRSV CP gene effectively protects local varieties of papaya against homologous and heterologous isolates of PRSV.


2003 ◽  
Vol 28 (6) ◽  
pp. 678-681 ◽  
Author(s):  
Marilia G. S. Della Vecchia ◽  
Luis E. A. Camargo ◽  
Jorge A. M. Rezende

This study compared three mild and three severe strains of Papaya ringspot virus - type W (PRSV-W), based on nucleotide and amino acid sequences of the capsid protein (CP) gene. The CP nucleotide sequences of the mild strains shared 98% to 100% identity. When compared to the severe strains the identity ranged from 93% to 95%, except in the case of PRSV-W-2R, which resulted from reversion of the mild strains PRSV-W-2. The CP sequence of the reverting strain showed 100% identity with the sequence of its parental strain. An insertion of six nucleotides in the core region of the CP gene, which reflected the addition of two amino acids (Asn and Asp) in the deduced sequence of the protein, was found in all mild strains. These sequence comparisons were used to design strain-specific primers that were used to specifically amplify regions for either the mild or severe strains.


Animals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2633
Author(s):  
Poh Chiang Chew ◽  
Annie Christianus ◽  
Jaapar M. Zudaidy ◽  
Md Yasin Ina-Salwany ◽  
Chou Min Chong ◽  
...  

In this study, a mixture of Tor tambra and T. tambroides with unknown genetic background were collected from 11 localities in Malaysia for broodstock development and sperm cryo-banking. This study aims to assess the microsatellite (simple sequence repeat, SSR) variation, genetic diversity, genetic differentiation, level of gene flow, population structure, genetic relatedness and their demographic aspects among these Tor populations, in addition to establishing their SSR profile by employing 22 SSR markers via fragment analysis. Total genomic DNA was extracted from 181 samples (91 cryopreserved milt samples and 90 scale samples of live broodfish). Results showed the Tor spp. collection retained their genetic variation but exhibited excessive homozygosity among individuals within population. Moderate genetic differentiation was shown among the populations, with highly significant (p < 0.001) fixation indices (FST, FIS and FIT). A low gene flow over all loci (Nm 1.548) indicates little genetic variation transfer between populations. The genetic structures of all the populations were successfully resolved into four main clusters by an unweighted pair group method with arithmetic mean (UPGMA) dendrogram generated based on Nei’s genetic distances. The population structures based on principal coordinates analysis (PCoA) and the Bayesian model also suggested four distinct clusters following geographical regions and eight closely related populations. This study provided a useful baseline reference for better genetic management and utilization of the Tor spp. stocks in their breeding and conservation programmes.


2010 ◽  
Vol 17 (1) ◽  
pp. 19-22 ◽  
Author(s):  
Maria Krzakowa ◽  
Marcin Michalak

Genetic differentiation of common reed (Phragmites australis) populations from selected lakes of Pomerania (NW Poland), revealed by electrophoretically detected peroxidase variabilityThree populations of common reed (Phragmites australis(Cav) Trin. ex Steud.), growing under differing edaphic conditions in lakes near the town of Koszalin (the Pomerania region in north-western Poland), were studied in respect to frequencies of electrophoretically detected allozymes in two peroxidase loci: a monomeric locus with three alleles and a dimeric locus with two alleles. On the basis of genetic distances, similarity between these populations and levels of variation were assessed both within populations (GST = 0.0376) and between populations (DST = 0.0194). Gene flow between populations was low (Nm= 6.399).


Plant Disease ◽  
2017 ◽  
Vol 101 (6) ◽  
pp. 985-993 ◽  
Author(s):  
Solomon Maina ◽  
Brenda A. Coutts ◽  
Owain R. Edwards ◽  
Luis de Almeida ◽  
Abel Ximenes ◽  
...  

To examine possible genetic connectivity between crop viruses found in Southeast Asia and Australia, Papaya ringspot virus biotype W (PRSV-W) isolates from cucurbits growing in East Timor and northern Australia were studied. East Timorese samples from cucumber (Cucumis sativus) or pumpkin (Cucurbita moschata and C. maxima) were sent to Australia on FTA cards. These samples and others of pumpkin, rockmelon, honeydew melon (Cucumis melo), or watermelon (Citrullus lanatus) growing in one location each in northwest, north, or northeast Australia were subjected to high throughput sequencing (HTS). When the 17 complete PRSV genomic sequences obtained by HTS were compared with 32 others from GenBank, the five from East Timor were in a different major phylogroup from the 12 Australian sequences. Moreover, the East Timorese and Australian sequences each formed their own minor phylogroups named VI and I, respectively. A Taiwanese sequence was closest to the East Timorese (89.6% nt dentity), and Mexican and Brazilian sequences were the closest to the Australian (92.3% nt identity). When coat protein gene (CP) sequences from the 17 new genomic sequences were compared with 126 others from GenBank, three Australian isolates sequenced more than 20 years ago grouped with the new Australian sequences, while the closest sequence to the East Timorese was from Thailand (93.1% nt identity). Recombination analysis revealed 13 recombination events among the 49 complete genomes. Two isolates from East Timor (TM50, TM32) and eight from GenBank were recombinants, but all 12 Australian isolates were non-recombinants. No evidence of genome connectivity between Australian and Southeast Asian PRSV populations was obtained. The strand-specific RNA library approach used optimized data collection for virus genome assembly. When an Australian PRSV isolate was inoculated to plants of zucchini (Cucurbita pepo), watermelon, rockmelon, and honeydew melon, they all developed systemic foliage symptoms characteristic of PRSV-W, but symptom severity varied among melon cultivars.


Plant Disease ◽  
2019 ◽  
Vol 103 (11) ◽  
pp. 2920-2924 ◽  
Author(s):  
Islam Hamim ◽  
Maher Al Rwahnih ◽  
Wayne B. Borth ◽  
Jon Y. Suzuki ◽  
Michael J. Melzer ◽  
...  

Papaya ringspot virus (PRSV) is the major constraint to papaya (Carica papaya) production in Bangladesh. Disease symptoms occurred in 90 to 100% of the plants surveyed. Full-length genomes of PRSV strains from severely infected papaya plants were determined using the Illumina NextSeq 500 platform, followed by Sanger DNA sequencing of viral genomes obtained by reverse-transcription PCR(RT-PCR). The genome sequences of two distinct PRSV strains, PRSV BD-1 (10,300 bp) and PRSV BD-2 (10,325 bp) were 74 and 83% identical to each other, respectively, at the nucleotide and amino acid levels. PRSV BD-1 and PRSV BD-2 were 74 to 75% and 79 to 88% identical, respectively, to other full-length PRSV sequences at the nucleotide level. Based on phylogenetic analysis, PRSV BD-2 was most closely related to PRSV-Meghalaya (MF356497) from papaya in India. PRSV BD-1 formed a branch distinct from the other PRSV sequences based on nucleotide and amino acid sequence comparisons. Comparisons of the genome sequences of these two strains with other sequenced PRSV genomes indicated two putative recombination events in PRSV BD-2. One recombinant event contained a 2,766-nucleotide fragment highly identical to PRSV-Meghalaya (MF356497). The other recombinant event contained a 5,105-nucleotide fragment highly identical to PRSV-China (KY933061). The occurrence rates of PRSV BD-1 and PRSV BD-2 in the sampled areas of Bangladesh were approximately 19 and 69%, respectively. Plants infected with both strains (11%) exhibited more severe symptoms than plants infected with either strain alone. The full-length genome sequences of these new PRSV strains and their distribution provide important information regarding the dynamics of papaya ringspot virus infections in papaya in Bangladesh.


2015 ◽  
Vol 106 (1) ◽  
pp. 124-134 ◽  
Author(s):  
C.X. Duan ◽  
W.C. Li ◽  
Z.D. Zhu ◽  
D.D. Li ◽  
S.L. Sun ◽  
...  

AbstractCallosobruchus chinensis (Linnaeus) is one of the most destructive pests of leguminous seeds. Genetic differentiation and diversity analysis of 345 C. chinensis individuals from 23 geographic populations using 20 polymorphic simple sequence repeats revealed a total of 149 alleles with an average of 7.45 alleles per locus. The average Shannon's information index was 1.015. The gene flow and genetic differentiation rate values at the 20 loci ranged from 0.201 to 1.841 and 11.0–47.2%, with averages of 0.849 and 24.4%, respectively. In the 23 geographic populations, the effective number of alleles and observed heterozygosity ranged from 1.441 to 2.218 and 0.191–0.410, respectively. Shannon's information index ranged from 0.357 to 0.949, with the highest value in Hohhot and the lowest in Rudong. In all comparisons, the fixation index (FST) values ranged from 0.049 to 0.441 with a total FST value of 0.254 among the 23 C. chinensis populations, indicating a moderate level of genetic differentiation and gene flow among these populations. Analysis of molecular variance revealed that the genetic variation within populations accounted for 76.7% of the total genetic variation. The genetic similarity values between populations varied from 0.617 to 0.969, whereas genetic distances varied from 0.032 to 0.483. Using unweighted pair-group method using arithmetical averages cluster analysis, the 23 geographic collections were classified into four distinct genetic groups but most of them were clustered into a single group. The pattern of the three concentrated groups from polymerase chain reactions analysis showed a somewhat different result with cluster.


2020 ◽  
Author(s):  
Anam Saleem ◽  
Zahid Ali ◽  
Shyi-Dong Yeh ◽  
Wajeeha Saeed ◽  
Amna Imdad ◽  
...  

Abstract The mutation prone RNA genome of Papaya ringspot virus could be a driving force behind its geographical spread and dissemination. Here we present the molecular investigations on atypical PRSV–P strain identified from Pakistan with genome sequence phylogenetic and recombination analysis. The PRSV-P, Pakistan outbreak strain showing a geographic spread across India and Bangladesh in phylogenetic lineage. In major recombination events, it has acquired genome variation in amino terminal of PRSV coat protein gene, whereas the gene for helper component-proteinase (HC–Pro), a nonstructural coding region of multi-domain provenance, also evolves at nucleotide and amino acid levels. The phylogenetic analysis of another highly variable P1 region showed evolutionary dynamics with respect to other geographical strains, particularly the Indian isolate from North East region (Meghalaya). PRSV–PK holds high levels of genetic divergence in comparison to American, Australian and Asian isolates. The genetic and phylogeographic analyses indicate that a spatial recombination has occurred from first PRSV, however temporal evolution is within the region of occurrence. The genetic variations and evolutionary dynamics of this virus may challenge the resistance developed in papaya against PRSV and give rise to virus lineage because of its atypical emergence where geographic spread is already occurring.


2002 ◽  
Vol 27 (2) ◽  
pp. 174-180 ◽  
Author(s):  
ROBERTO C. A. LIMA ◽  
MANOEL T. SOUZA JR. ◽  
GILVAN PIO-RIBEIRO ◽  
J. ALBERSIO A. LIMA

Papaya ringspot virus (PRSV) is the causal agent of the main papaya (Carica papaya) disease in the world. Brazil is currently the world's main papaya grower, responsible for about 40% of the worldwide production. Resistance to PRSV on transgenic plants expressing the PRSV coat protein (cp) gene was shown to be dependent on the sequence homology between the cp transgene expressed in the plant genome and the cp gene from the incoming virus, in an isolate-specific fashion. Therefore, knowledge of the degree of homology among the cp genes from distinct PRSV isolates which are present in a given area is important to guide the development of transgenic papaya for the control of PRSV in that area. The objective of the present study was to assess the degree of homology among the PRSV cp genes of several Brazilian isolates of this virus. Papaya and PRSV are present in many different ecosystems within Brazil. Twelve PRSV isolates, collected in eight different states from four different geographic regions, were used in this study. The sequences of the cp gene from these isolates were compared among themselves and to the gene used to generate transgenic papaya for Brazil. An average degree of homology of 97.3% at the nucleotide sequence was found among the Brazilian isolates. When compared to 27 isolates from outside Brazil in a homology tree, the Brazilian isolates were clustered with Australian, Hawaiian, and Central and North American isolates, with an average degree of homology of 90.7% among them.


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