Rpi-vnt1.1, a Tm-22 Homolog from Solanum venturii, Confers Resistance to Potato Late Blight

Despite the efforts of breeders and the extensive use of fungicide control measures, late blight still remains a major threat to potato cultivation worldwide. The introduction of genetic resistance into cultivated potato is considered a valuable method to achieve durable resistance to late blight. Here, we report the identification and cloning of Rpi-vnt1.1, a previously uncharacterized late-blight resistance gene from Solanum venturii. The gene was identified by a classical genetic and physical mapping approach and encodes a coiled-coil nucleotide-binding leucine-rich repeat protein with high similarity to Tm-22 from S. lycopersicum which confers resistance against Tomato mosaic virus. Transgenic potato and tomato plants carrying Rpi-vnt1.1 were shown to be resistant to Phytophthora infestans. Of 11 P. infestans isolates tested, only isolate EC1 from Ecuador was able to overcome Rpi-vnt1.1 and cause disease on the inoculated plants. Alleles of Rpi-vnt1.1 (Rpi-vnt1.2 and Rpi-vnt1.3) that differed by only a few nucleotides were found in other late-blight-resistant accessions of S. venturii. The late blight resistance gene Rpi-phu1 from S. phureja is shown here to be identical to Rpi-vnt1.1, suggesting either that this strong resistance gene has been maintained since a common ancestor, due to selection pressure for blight resistance, or that genetic exchange between S. venturii and S. phureja has occurred at some time.

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Performance of Transgenic Potato Containing the Late Blight Resistance Gene RB

Plant Disease ◽

10.1094/pdis-92-3-0339 ◽

2008 ◽

Vol 92 (3) ◽

pp. 339-343 ◽

Cited By ~ 52

Author(s):

Dennis A. Halterman ◽

Lara Colton Kramer ◽

Susan Wielgus ◽

Jiming Jiang

Keyword(s):

Late Blight ◽

Resistance Gene ◽

Late Blight Resistance ◽

Transgenic Potato ◽

Field Trials ◽

Blight Resistance ◽

Solanum Bulbocastanum ◽

Wild Potato Species ◽

Foliar Resistance ◽

In The Wild

Late blight of potato, caused by Phytophthora infestans, is one of the most devastating diseases of potato. A major late blight resistance gene, called RB, previously was identified in the wild potato species Solanum bulbocastanum through map-based cloning. The full-length gene coding sequence, including the open reading frame and promoter, has been integrated into cultivated potato (S. tuberosum) using Agrobacterium-mediated transformation. RB-containing transgenic plants were challenged with P. infestans under optimal late blight conditions in greenhouse experiments. All transgenic lines containing RB exhibited strong foliar resistance. Field-grown transgenic tubers also were tested for resistance to P. infestans. In contrast to the foliar resistance phenotype, RB-containing tubers did not exhibit increased resistance. Two years of field trials were used to ascertain whether the presence of RB had any effect on tuber yield. We were unable to detect any significant effect on tuber size or yield after addition of the resistance gene to several S. tuberosum cultivars.

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Late Blight Resistance of RB Transgenic Potato Lines

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.132.6.783 ◽

2007 ◽

Vol 132 (6) ◽

pp. 783-789 ◽

Cited By ~ 26

Author(s):

Joseph C. Kuhl ◽

Kelly Zarka ◽

Joseph Coombs ◽

William W. Kirk ◽

David S. Douches

Keyword(s):

Late Blight ◽

Resistance Gene ◽

Late Blight Resistance ◽

Transgenic Potato ◽

Kanamycin Resistance ◽

Field Resistance ◽

State University ◽

Solanum Bulbocastanum ◽

Native Promoter ◽

Transgenic Lines

Late blight of potato (Solanum tuberosum L.), incited by Phytophthora infestans (Mont.) de Bary, is a devastating disease affecting tuber yield and storage. Recent work has isolated a resistance gene, RB, from the wild species Solanum bulbocastanum Dun. Earlier work in Toluca, Mexico, observed significant levels of field resistance under intense disease pressure in a somatic hybrid containing RB. In this study, five transgenic RB lines were recovered from the late blight susceptible line MSE149-5Y, from the Michigan State University (MSU) potato breeding program. Transgenic lines were molecularly characterized for the RB transgene, RB transcript, and insertion number of the kanamycin resistance gene NPTII. Transgenic lines and the parent line were evaluated for resistance in field and laboratory tests. Molecular characterization alone did not predict which lines were resistant. Three of the RB transformed MSE149-5Y lines showed increased resistance under field conditions at MSU and increased resistance in detached leaf evaluations using multiple isolates individually (US-1, US-1.7, US-8, US-10, and US-14). Transfer of RB into late blight susceptible and resistant lines could provide increased protection to potato late blight. The use of the RB gene for transformation in this way creates a partially cisgenic event in potato because the gene's native promoter and terminator are used. This type of transformation provides a chance to generate greater public acceptance of engineered approaches to trait introgression in food crops.

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Genetic Diversity in Diploid and Tetraploid Late Blight Resistant Potato Germplasm

HortScience ◽

10.21273/hortsci.37.1.178 ◽

2002 ◽

Vol 37 (1) ◽

pp. 178-183 ◽

Cited By ~ 7

Author(s):

Dilson A. Bisognin ◽

David S. Douches

Keyword(s):

Genetic Diversity ◽

Late Blight ◽

Durable Resistance ◽

Late Blight Resistance ◽

Blight Resistance ◽

Pair Group ◽

Potato Germplasm ◽

Genetic Base ◽

The Matrix ◽

Isozyme Loci

An understanding of the genetic relationship within potato germplasm is important to establish a broad genetic base for breeding purposes. The objective of this study was to assess the genetic diversity of potato (Solanum tuberosum subsp. tuberosum Hawkes) germplasm that can be used in the development of cultivars with resistance to late blight caused by Phytophthora infestans (Mont.) de Bary. Thirty-three diploid and 27 tetraploid late blight resistant potato clones were evaluated for their genetic diversity based on 11 isozyme loci and nine microsatellites. A total of 35 allozymes and 42 polymorphic microsatellite fragments was scored for presence or absence. The germplasm was clustered based on the matrix of genetic similarities and the unweighted pair group means analysis of the isozyme and microsatellite data, which were used to construct a dendrogram using NTSYS-pc version 1.7. Twenty-three allozymes and DNA fragments were unique to the wild species. The diploid Solanum species S. berthaultii Hawkes and S. microdontum Bitter formed two distinct phenetic groups. Within S. microdontum, three subgroups were observed. The tetraploid germplasm formed another group, with S. sucrense Hawkes in one subgroup and the cultivated potato and Russian hybrids in another subgroup. Based upon the genetic diversity and the level of late blight resistance, S. microdontum and S. sucrense offer the best choice for strong late blight resistance from genetically diverse sources. This potato germplasm with reported late blight resistance should be introgressed into the potato gene pool to broaden the genetic base to achieve stronger and more durable resistance.

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Faculty Opinions recommendation of Accelerated cloning of a potato late blight-resistance gene using RenSeq and SMRT sequencing.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.726310370.793518186 ◽

2016 ◽

Author(s):

Jiming Jiang

Keyword(s):

Late Blight ◽

Resistance Gene ◽

Late Blight Resistance ◽

Potato Late Blight ◽

Blight Resistance ◽

Smrt Sequencing

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Evaluation of the RPi-ber late blight resistance gene for tuber resistance in the field and laboratory

Plant Breeding ◽

10.1111/j.1439-0523.2010.01836.x ◽

2011 ◽

Vol 130 (4) ◽

pp. 464-468 ◽

Cited By ~ 4

Author(s):

Hilary Mayton ◽

Gilda Rauscher ◽

Ivan Simko ◽

William E. Fry

Keyword(s):

Late Blight ◽

Resistance Gene ◽

Late Blight Resistance ◽

Blight Resistance ◽

Tuber Resistance

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Characterisation of the late blight resistance in potato differential MaR9 reveals a qualitative resistance gene, R9a, residing in a cluster of Tm-2 2 homologs on chromosome IX

Theoretical and Applied Genetics ◽

10.1007/s00122-015-2480-6 ◽

2015 ◽

Vol 128 (5) ◽

pp. 931-941 ◽

Cited By ~ 18

Author(s):

Kwang-Ryong Jo ◽

Richard G. F. Visser ◽

Evert Jacobsen ◽

Jack H. Vossen

Keyword(s):

Late Blight ◽

Resistance Gene ◽

Late Blight Resistance ◽

Blight Resistance ◽

Qualitative Resistance

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Higher Copy Numbers of the Potato RB Transgene Correspond to Enhanced Transcript and Late Blight Resistance Levels

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-22-4-0437 ◽

2009 ◽

Vol 22 (4) ◽

pp. 437-446 ◽

Cited By ~ 72

Author(s):

James M. Bradeen ◽

Massimo Iorizzo ◽

Dimitre S. Mollov ◽

John Raasch ◽

Lara Colton Kramer ◽

...

Keyword(s):

Disease Resistance ◽

Late Blight ◽

Resistance Gene ◽

Resistance Genes ◽

Rna Silencing ◽

Late Blight Resistance ◽

Blight Resistance ◽

Transcript Levels ◽

Cultivated Potato ◽

Copy Numbers

Late blight of potato ranks among the costliest of crop diseases worldwide. Host resistance offers the best means for controlling late blight, but previously deployed single resistance genes have been short-lived in their effectiveness. The foliar blight resistance gene RB, previously cloned from the wild potato Solanum bulbocastanum, has proven effective in greenhouse tests of transgenic cultivated potato. In this study, we examined the effects of the RB transgene on foliar late blight resistance in transgenic cultivated potato under field production conditions. In a two-year replicated trial, the RB transgene, under the control of its endogenous promoter, provided effective disease resistance in various genetic backgrounds, including commercially prominent potato cultivars, without fungicides. RB copy numbers and transcript levels were estimated with transgene-specific assays. Disease resistance was enhanced as copy numbers and transcript levels increased. The RB gene, like many other disease resistance genes, is constitutively transcribed at low levels. Transgenic potato lines with an estimated 15 copies of the RB transgene maintain high RB transcript levels and were ranked among the most resistant of 57 lines tested. We conclude that even in these ultra–high copy number lines, innate RNA silencing mechanisms have not been fully activated. Our findings suggest resistance-gene transcript levels may have to surpass a threshold before triggering RNA silencing. Strategies for the deployment of RB are discussed in light of the current research.

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