Occurrence of Three Recombinant Strains of Potato Virus Y in Potato in Kazakhstan

Potato virus Y (PVY) exists as a complex of strains, many of which are recombinants. The practical importance of PVY recombinant strains has increased due to their ability to induce potato tuber necrotic ring spot disease (PTNRD) that seriously affects tuber quality. In Saudi Arabia, potato production has increased fivefold during the last three decades, reaching 460,000 tons per year. Although PVY has been reported as one of the main viruses affecting potatoes, no information is available on PVY strains circulating in the country. In August 2014, a survey was conducted in a seed potato field at Al-Jouf, Saudi Arabia. PVY-positive samples selected based on visual symptoms and serological reactivity were subjected to strain typing using multiplex RT-PCR assays and were determined to represent recombinant PVY strains. Whole genome sequences were determined for two representative isolates, S2 and S9, through direct sequencing of a series of overlapping RT-PCR fragments for each isolate, and found to represent strains PVY-NE11 and PVYZ (SYR-III), respectively. One of the recombinant types, SYR-III, was previously found in nearby Syria and Jordan, but the second recombinant, PVY-NE11, was found before only in the United States. Both recombinants, PVY-NE11 and SYR-III, were previously found associated with PTNRD and thought to be rare. The current identification of PVY-NE11 and SYR-III in seed potato in a new geographic region suggests that these recombinants may not be as rare as previously believed. This is the first report on the occurrence of recombinant strains of PVY in potato in Saudi Arabia, and the first report on the PVY-NE11 strain of PVY found in potato outside of the United States.

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Sequential acquisition of Potato virus Y strains by Myzus persicae favors the transmission of the emerging recombinant strains

Virus Research ◽

10.1016/j.virusres.2017.06.023 ◽

2017 ◽

Vol 241 ◽

pp. 116-124 ◽

Cited By ~ 3

Author(s):

Shaonpius Mondal ◽

Stewart M. Gray

Keyword(s):

Potato Virus ◽

Myzus Persicae ◽

Potato Virus Y ◽

Recombinant Strains ◽

Sequential Acquisition

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Tuber Symptoms Associated with Recombinant Strains of Potato virus Y in Specialty Potatoes Under Western Washington Growing Conditions

American Journal of Potato Research ◽

10.1007/s12230-015-9472-6 ◽

2015 ◽

Vol 92 (5) ◽

pp. 593-602 ◽

Cited By ~ 10

Author(s):

C. A. Benedict ◽

D. W. McMoran ◽

D. A. Inglis ◽

A. V. Karasev

Keyword(s):

Potato Virus ◽

Potato Virus Y ◽

Recombinant Strains ◽

Western Washington ◽

Growing Conditions

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Occurrence of Diverse Recombinant Strains of Potato virus Y Circulating in Potato Fields in Egypt

Plant Disease ◽

10.1094/pdis-02-17-0275-re ◽

2017 ◽

Vol 101 (8) ◽

pp. 1463-1469 ◽

Cited By ~ 10

Author(s):

Esraa A. Elwan ◽

Engy E. Abdel Aleem ◽

Faiza A. Fattouh ◽

Kelsie J. Green ◽

Lisa T. Tran ◽

...

Keyword(s):

Potato Tuber ◽

Potato Virus ◽

Potato Virus Y ◽

Molecular Properties ◽

Whole Genome ◽

The Novel ◽

Limited Information ◽

Genome Sequences ◽

Recombinant Strains ◽

Virus Strains

Potato is one of the staple crops in Egypt, grown under irrigation almost continuously year-round. Potato virus Y (PVY) has been reported as one of the main viruses affecting potatoes in Egypt, but limited information is available on PVY strains circulating in potato fields in the country. From 2014 to 2016, virus surveys were conducted in several potato-growing governorates of Egypt, and PVY-positive samples were found to represent at least five distinct recombinant PVY strains, including PVYNTN and PVYN-Wi. Whole genome sequences were determined for four isolates representing strains PVY-SYR-III (Egypt7), PVY-261-4 (Egypt11), PVYNTNa (Egypt35), and a novel recombinant named Egypt24 that combined molecular properties of strains PVY-261-4 and PVY-Wilga156var. At least three recombinants found in Egypt in potato were previously found associated with potato tuber necrotic ringspot disease (PTNRD). The identification of multiple recombinant types of PVY in potato in Egypt, including the novel recombinant Egypt24, suggests a wide presence of PTNRD-inducing virus strains in the country.

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Virus and helper component interactions favour the transmission of recombinant potato virus Y strains

Journal of General Virology ◽

10.1099/jgv.0.001620 ◽

2021 ◽

Vol 102 (6) ◽

Author(s):

Shaonpius Mondal ◽

William M. Wintermantel ◽

Stewart M. Gray

Keyword(s):

Potato Virus ◽

Potato Virus Y ◽

Potato Crop ◽

Virus Binding ◽

Helper Component ◽

Recombinant Strains ◽

Homologous Virus ◽

The Usa ◽

Acquisition Order ◽

Ordinary Strain

In recent years, several recombinant strains of potato virus Y, notably PVYNTN and PVYN:O have displaced the ordinary strain, PVYO, and emerged as the predominant strains affecting the USA potato crop. Previously we reported that recombinant strains were transmitted more efficiently than PVYO when they were acquired sequentially, regardless of acquisition order. In another recent study, we showed that PVYNTN binds preferentially to the aphid stylet over PVYO when aphids feed on a mixture of PVYO and PVYNTN. To understand the mechanism of this transmission bias as well as preferential virus binding, we separated virus and active helper component proteins (HC), mixed them in homologous and heterologous combinations, and then fed them to aphids using Parafilm sachets. Mixtures of PVYO HC with either PVYN:O or PVYNTN resulted in efficient transmission. PVYN:O HC also facilitated the transmission of PVYO and PVYNTN, albeit with reduced efficiency. PVYNTN HC failed to facilitate transmission of either PVYO or PVYN:O. When PVYO HC or PVYN:O HC was mixed with equal amounts of the two viruses, both viruses in all combinations were transmitted at high efficiencies. In contrast, no transmission occurred when combinations of viruses were mixed with PVYNTN HC. Further study evaluated transmission using serial dilutions of purified virus mixed with HCs. While PVYNTN HC only facilitated the transmission of the homologous virus, the HCs of PVYO and PVYN:O facilitated the transmission of all strains tested. This phenomenon has likely contributed to the increase in the recombinant strains affecting the USA potato crop.

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Strain-Specific Resistance to Potato virus Y (PVY) in Potato and Its Effect on the Relative Abundance of PVY Strains in Commercial Potato Fields

Plant Disease ◽

10.1094/pdis-06-16-0901-re ◽

2017 ◽

Vol 101 (1) ◽

pp. 20-28 ◽

Cited By ~ 44

Author(s):

Cassandra N. Funke ◽

Olga V. Nikolaeva ◽

Kelsie J. Green ◽

Lisa T. Tran ◽

Mohamad Chikh-Ali ◽

...

Keyword(s):

Potato Virus ◽

Potato Virus Y ◽

Specific Resistance ◽

Potato Production ◽

The United States ◽

Potato Cultivars ◽

Columbia Basin ◽

Recombinant Strains ◽

Systemic Movement ◽

Production Area

Potato virus Y (PVY) is a serious threat to potato production due to effects on tuber yield and quality, in particular, due to induction of potato tuber necrotic ringspot disease (PTNRD), typically associated with recombinant strains of PVY. These recombinant strains have been spreading in the United States for the past several years, although the reasons for this continuing spread remained unclear. To document and assess this spread between 2011 and 2015, strain composition of PVY isolates circulating in the Columbia Basin potato production area was determined from hundreds of seed lots of various cultivars. The proportion of nonrecombinant PVYO isolates circulating in Columbia Basin potato dropped ninefold during this period, from 63% of all PVY-positive plants in 2011 to less than 7% in 2015. This drop in PVYO was concomitant with the rise of the recombinant PVYN-Wi strain incidence, from less than 27% of all PVY-positive plants in 2011 to 53% in 2015. The proportion of the PVYNTN recombinant strain, associated with PTNRD symptoms in susceptible cultivars, increased from 7% in 2011 to approximately 24% in 2015. To further address the shift in strain abundance, screenhouse experiments were conducted and revealed that three of the four most popular potato cultivars grown in the Columbia Basin exhibited strain-specific resistance against PVYO. Reduced levels of systemic movement of PVYO in such cultivars would favor spread of recombinant strains in the field. The negative selection against the nonrecombinant PVYO strain is likely caused by the presence of the Nytbr gene identified in potato cultivars in laboratory experiments. Presence of strain-specific resistance genes in potato cultivars may represent the driving force changing PVY strain composition to predominantly recombinant strains in potato production areas.

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Molecular and Serological Typing of Potato virus Y Isolates from Brazil Reveals a Diverse Set of Recombinant Strains

Plant Disease ◽

10.1094/pdis-02-12-0163-re ◽

2012 ◽

Vol 96 (10) ◽

pp. 1451-1458 ◽

Cited By ~ 20

Author(s):

Suellen B. F. Galvino-Costa ◽

Antonia dos Reis Figueira ◽

Francisco de Assis Câmara Rabelo-Filho ◽

Flavio Henrique Reis Moraes ◽

Olga V. Nikolaeva ◽

...

Keyword(s):

Potato Virus ◽

Potato Virus Y ◽

Enzyme Linked Immunosorbent Assay ◽

Correct Identification ◽

Single Mutation ◽

Strain Group ◽

Recombinant Strains ◽

Serological Profile ◽

Serological Typing ◽

Serological Reactivity

In Brazil, Potato virus Y (PVY) currently presents a significant problem for potato production, reducing tuber yield and quality. Recombinant tuber necrotic isolates of PVY had been reported to occur in the country but no systematic study of the PVY isolate diversity was conducted thus far. Here, a panel of 36 PVY isolates, randomly collected in Brazil from potato between 1985 and 2009, was subjected to a systematic molecular and serological typing using reverse-transcription polymerase chain reaction and a series of PVYO- and PVYN-specific monoclonal antibodies. The data collected were combined with biological characterization of the same isolates in tobacco. Of the 36 isolates tested, 3 were typed as PVYO, 10 as PVYN:O/N-Wi, 21 as PVYNTN, and 2 as “unusual” or inconclusive. Of the 10 isolates from the recombinant PVYN:O/N-Wi strain group, 1 isolate, MAF-VOY, was found to have an unusual serological profile identical to the nonrecombinant PVYO-O5 strain group. The 21 tested PVYNTN isolates included 1 isolate that did not induce vein necrosis in tobacco and 2 isolates with an unusual serological profile (i.e., displaying negative reactivity to one commercial PVYN-specific monoclonal antibody). Whole genome sequences were determined for four PVY isolates from Brazil, representing PVYO, PVYNTN, and PVYN-Wi strains. The genome of the MAF-VOY isolate was found to be recombinant, having characteristic N-Wi structure with two recombinant junctions and carrying a single mutation in the capsid protein at position 98, which led to an unusual O5 serological reactivity. Taken together, the data obtained suggest that the two recombinant strains, PVYNTN and PVYN:O/N-Wi, now are apparently dominant in the Brazilian potato crop. The data also suggest that recombinant isolates in Brazil often have unusual serological reactivity which may hamper their correct identification by conventional typing based on enzyme-linked immunosorbent assay.

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First Report of Recombinant Potato virus Y Strains Infecting Potato in Jordan

Plant Disease ◽

10.1094/pdis-03-14-0236-pdn ◽

2014 ◽

Vol 98 (7) ◽

pp. 1017-1017

Author(s):

G. Anfoka ◽

F. Haj Ahmad ◽

M. Altaleb ◽

M. Al Shhab ◽

S. Abubaker ◽

...

Keyword(s):

Potato Virus ◽

Potato Virus Y ◽

Solanum Tuberosum L ◽

Potato Crop ◽

Potato Production ◽

First Report ◽

Recombinant Strains ◽

Potato Plants ◽

Three Samples ◽

Aphid Vectors

Potato (Solanum tuberosum L.) is an important vegetable crop in Jordan, occupying second position after olives. In 2012, potatoes were planted on about 6,000 ha with a production of about 141,000 t (2). Potato virus Y (PVY) is a serious problem for potato production worldwide. Recombinant strains of the virus were reported to cause tuber necrotic ringspot disease (PTNRD) in many potato-growing regions of the world. In the last few years, a new recombinant PVYNTN-NW that belongs to PVYZ (3) has been reported in the neighboring Syria. It included three recombination patterns, SYR-I, SYR-II, and SYR-III, and caused severe PTNRD (1). Since PVY is easily transmitted from one region to another by aphid vectors and infected potato seeds, this study was initiated to investigate the possible occurrence of PVY strains in Jordan. In October 2013, 33 leaf samples were collected from symptomatic potato plants cv. Spunta from Wadi Rum, Jordan (GPS coordinates 29°31′37.76″ N, 35°42′48.75″ E), the largest potato-producing area in Jordan. Sampled plants displayed leaf mottling and yellowing, symptoms similar to those caused by PVY. All samples were tested for PVY by DAS-ELISA using the ELISA kit (monoclonal cocktail) developed by BIOREBA (Reinach, Switzerland) to detect all PVY isolates. Twenty-nine samples were found positive for PVY by ELISA. To confirm virus infection, total RNA was extracted from all ELISA-positive samples and used as template in uniplex RT-PCR using strain-specific primers (1). The band pattern of PCR amplicons showed that 12 samples were infected with PVYNTN-NW genotype SYR-III and produced bands of 1,085, 441, and 278 bp. One sample was infected with PVYNTN (A) and produced bands of 1,307, 633, and 441 bp, and one other sample was infected with PVYNTN-NW genotype SYR-II and produced bands of 1,085 and 441 bp. Mixed infection with PVYNTN-NW genotype SYR-III and PVYNTN (B) was also detected in one sample producing bands of 278, 441, 1,085, and 1,307 bp. To confirm infection with the recombinant strains, PCR fragments of 278 bp amplified from three samples and 1,085 bp obtained from another three samples were directly sequenced and sequences were deposited in GenBank under accession numbers KJ159968, KJ159969, and KJ159970 for the 278-bp fragment and KJ159974, KJ159975, and KJ159976 for the 1,085-bp fragment. Sequence comparison with other PVY strains available in the NCBI database showed that the 278-bp fragment had the highest nucleotide sequence identity (100%) with PVY isolates SYR-III-A26 (AB461467) and SYR-III-2-4 (AB461457) from Syria. BLAST searches also showed that the 1,085-bp fragment shared 99% nucleotide identities with PVY isolates SYR-II-L3 (AB461482) and SYR-II-Be4 (AB461474) from Aleppo, Syria. To our knowledge, this is the first report of PVY recombinants in Jordan, and the first report of PVYNTN-NW recombinants infecting potato crop outside Syria. Since Europe is the main supplier of potato seeds for farmers in Jordan and Syria, the introduction of PVYNTN-NW to the region could have happened through infected potato seeds. Results of this study create new challenges for potato growers in Jordan as well as other countries in the region. References: (1) M. Chikh Ali et al. J. Virol. Methods 165:15, 2010. (2) FAO. http://faostat.fao.org/ (3) A. V. Karasev and S. M. Gray. Ann. Rev. Phytopathol. 51:571, 2013.

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Potato virus Y Transmission Efficiency from Potato Infected with Single or Multiple Virus Strains

Phytopathology ◽

10.1094/phyto-09-16-0322-r ◽

2017 ◽

Vol 107 (4) ◽

pp. 491-498 ◽

Cited By ~ 7

Author(s):

Shaonpius Mondal ◽

Yu-Hsuan Lin ◽

Juliet E. Carroll ◽

Erik J. Wenninger ◽

Nilsa A. Bosque-Pérez ◽

...

Keyword(s):

Potato Virus ◽

Potato Virus Y ◽

Green Peach Aphid ◽

Potato Crop ◽

Potato Cultivar ◽

Aphid Transmission ◽

The United States ◽

Transmission Efficiency ◽

Recombinant Strains ◽

Virus Strains

There has been a recent shift in the prevalence of Potato virus Y (PVY) strains affecting potato with the ordinary strain PVYO declining and the recombinant strains PVYNTN and PVYN:O emerging in the United States. Multiple PVY strains are commonly found in potato fields and even in individual plants. Factors contributing to the emergence of the recombinant strains are not well defined but differential aphid transmission of strains from single and mixed infections may play a role. We found that the transmission efficiencies by Myzus persicae, the green peach aphid, of PVYNTN, PVYN:O, and PVYO varied depending on the potato cultivar serving as the virus source. Overall transmission efficiency was highest from sources infected with three virus strains, whereas transmission from sources infected with one or two virus strains was not significantly different. Two strains were concomitantly transmitted by individual aphids from many of the mixed-source combinations, especially if PVYO was present. Triple-strain infections were not transmitted by any single aphid. PVYO was transmitted most efficiently from mixed-strain infection sources. The data do not support the hypothesis that differential transmission of PVY strains by M. persicae is a major contributing factor in the emergence of recombinant PVY strains in the U.S. potato crop.

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