New Findings on the Resistance Mechanism of an Elite Diploid Wild Potato Species JAM1-4 in Response to a Super Race Strain of Phytophthora infestans

Late blight is a devastating potato disease worldwide, caused by Phytophthora infestans. The P. infestans strain 2013-18-306 from Yunnan is a “supervirulent race” that overcomes all 11 known late blight resistance genes (R1 to R11) from Solanum demissum. In a previous study, we identified a diploid wild-type potato JAM1-4 (S. jamesii) with high resistance to 2013-18-306. dRenSeq analysis indicated the presence of novel R genes in JAM1-4. RNA-Seq was used to analyze the late blight resistance response genes and defense regulatory mechanisms of JAM1-4 against 2013-18-306. Gene ontology enrichment and KEGG pathway analysis showed that many disease-resistant pathways were significantly enriched. Analysis of differentially expressed genes (DEGs) revealed an active disease resistance mechanism of JAM1-4, and the essential role of multiple signal transduction pathways and secondary metabolic pathways comprised of SA-JA-ET in plant immunity. We also found that photosynthesis in JAM1-4 was inhibited to promote the immune response. Our study reveals the pattern of resistance-related gene expression in response to a super race strain of potato late blight and provides a theoretical basis for further exploration of potato disease resistance mechanisms, discovery of new late blight resistance genes, and disease resistance breeding.

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Two Tomato (Solanum lycopersicum) Thaumatin-like Protein Genes Confer Enhanced Resistance to Late Blight (Phytophthora infestans)

Phytopathology ◽

10.1094/phyto-06-20-0237-r ◽

2021 ◽

Author(s):

Haishan Zhu ◽

Minghua Deng ◽

Zhengan Yang ◽

Lianzhen Mao ◽

Shurui Jiang ◽

...

Keyword(s):

Disease Resistance ◽

Late Blight ◽

Phytophthora Infestans ◽

Resistance Genes ◽

Single Gene ◽

Expression Patterns ◽

Late Blight Resistance ◽

Inbred Lines ◽

Blight Resistance ◽

Tomato Production

Late blight (caused by Phytophthora infestans) poses a serious threat to tomato production, but the number of late blight resistance genes isolated from tomato is limited, making resistance gene mining a high research priority. In this study, highly resistant CLN2037E and susceptible No.5 tomato inbred lines were used to identify late blight resistance genes. Using transcriptome sequencing, we discovered 36 differentially expressed genes (DEGs), including 21 nucleotide binding site-leucine-rich repeat (NBS-LRR) and 15 pathogenesis-related (PR) disease resistance genes. Cluster analysis and real-time quantitative PCR (RT-qPCR) showed that these 36 genes possessed similar expression patterns in different inbred lines after inoculation with P. infestans. Moreover, two PR genes with unique responses were chosen to verify their functions when exposed to P. infestans: Solyc08g080660 and Solyc08g080670, both of which were thaumatin-like protein (TLP) genes and were clustered in the tomato genome. Functions of these two genes were identified by gene overexpression and gene editing technology. Overexpression and knockout of single Solyc08g080660 and Solyc08g080670 corresponded to an increase and decrease in resistance to late blight, respectively, and Solyc08g080660 led to a greater change in disease resistance compared with Solyc08g080670. Co-transformation of dual genes resulted in a much greater effect than any single gene. This study provides novel candidate resistance genes for tomato breeding against late blight and insights into the interaction mechanisms between tomato and P. infestans.

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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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Virulence of Phytophthora infestans isolates from potato in Spain

Plant Protection Science ◽

10.17221/39/2021-pps ◽

2021 ◽

Vol 57 (No. 4) ◽

pp. 279-288

Author(s):

Jose Ignacio Ruiz de Galarreta ◽

Alba Alvarez-Morezuelas ◽

Nestor Alor ◽

Leire Barandalla ◽

Enrique Ritter

Keyword(s):

Late Blight ◽

Phytophthora Infestans ◽

Late Blight Resistance ◽

Blight Resistance ◽

Genetic Changes ◽

Detached Leaves ◽

Severity Of The Disease ◽

Pathogen Populations ◽

Incompatibility Reactions

The oomycete Phytophthora infestans is responsible for the disease known as late blight in potato and tomato. It is the plant pathogen that has caused the greatest impact on humankind so far and, despite all the studies that have been made, it remains the most important in this crop. In Spain during the last years a greater severity of the disease has been observed in both, potato and tomato, probably due to genetic changes in pathogen populations described recently. The aim of this study was the characterization of the physiological strains of 52 isolates of P. infestans obtained in different potato-growing areas in Spain. For this purpose, inoculations on detached leaves were performed in order to determine compatibility or incompatibility reactions. A total of 17 physiological races were found. The less frequent virulence factors were Avr5 and Avr8. By studying the epidemiology of the pathogen, a specific breeding program for late blight resistance can be implemented.

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Transcriptome analysis of scions grafted to potato rootstock for improving late blight resistance

10.21203/rs.3.rs-58639/v2 ◽

2020 ◽

Author(s):

Yuexin Li ◽

Degang Zhao

Keyword(s):

Disease Resistance ◽

Late Blight ◽

Protein Kinases ◽

Molecular Mechanisms ◽

Late Blight Resistance ◽

Potato Late Blight ◽

Susceptible Variety ◽

Resistant Variety ◽

Blight Resistance ◽

Expression Levels

Abstract Background: Late blight seriously threatens potato cultivation worldwide. The severe and widespread damage caused by the fungal pathogen can lead to drastic decreases in potato yield. Although grafting technology has been widely used to improve crop resistance, the effects of grafting on potato late blight resistance as well as the associated molecular mechanisms remain unclear. Therefore, we performed RNA transcriptome sequencing analysis and the late blight resistance testing of the scion when the potato late blight-resistant variety Qingshu 9 and the susceptible variety Favorita were used as the rootstock and scion, respectively, and vice versa. The objective of this study was to evaluate the influence of the rootstock on scion disease resistance and to clarify the related molecular mechanisms.Results: A Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis revealed that the expression levels of genes related to plant–pathogen interactions, plant mitogen-activated protein kinase (MAPK) signaling pathways, and plant hormone signal transduction pathways were significantly up-regulated in the scion when Qingshu 9 was used as the rootstock. These genes included late blight response genes encoding calcium-dependent protein kinases (CDPKs), chitin elicitor receptor kinases (CERKs), LRR receptor serine/threonine protein kinases (LRR-LRKs), NPR family proteins in the salicylic acid synthesis pathway, and MAPKs. When Favorita was used as the rootstock, the expression levels of the late blight response genes were not up-regulated in the Qingshu 9 scion, but the expression levels of the genes related to proline metabolism, fatty acid chain elongation, and diterpenoid biosynthesis pathways were down-regulated. Resistance results showed that self-grafting of the susceptible variety and grafting with the resistant variety as the rootstock increased the resistance of the susceptible scion to late blight. However, the resistance was stronger after grafting with the resistant variety as the rootstock. Using the susceptible variety as the rootstock decreased the late blight resistance of the resistant scion.Conclusions: Our results showed that changes to the expression of disease resistance genes in the scion after grafting are associated with late blight resistance. The results provide the basis for exploring the molecular mechanism underlying the effects of rootstocks on scion disease resistance.

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Detection of Novel QTLs for Late Blight Resistance Derived from the Wild Potato Species Solanum microdontum and Solanum pampasense

Genes ◽

10.3390/genes11070732 ◽

2020 ◽

Vol 11 (7) ◽

pp. 732

Author(s):

Fergus Meade ◽

Ronald Hutten ◽

Silke Wagener ◽

Vanessa Prigge ◽

Emmet Dalton ◽

...

Keyword(s):

Late Blight ◽

Resistance Genes ◽

Late Blight Resistance ◽

Gene Clusters ◽

Genetic Maps ◽

Blight Resistance ◽

Wild Potato ◽

Wild Potato Species ◽

Potato Species ◽

Solanum Microdontum

Wild potato species continue to be a rich source of genes for resistance to late blight in potato breeding. Whilst many dominant resistance genes from such sources have been characterised and used in breeding, quantitative resistance also offers potential for breeding when the loci underlying the resistance can be identified and tagged using molecular markers. In this study, F1 populations were created from crosses between blight susceptible parents and lines exhibiting strong partial resistance to late blight derived from the South American wild species Solanum microdontum and Solanum pampasense. Both populations exhibited continuous variation for resistance to late blight over multiple field-testing seasons. High density genetic maps were created using single nucleotide polymorphism (SNP) markers, enabling mapping of quantitative trait loci (QTLs) for late blight resistance that were consistently expressed over multiple years in both populations. In the population created with the S. microdontum source, QTLs for resistance consistently expressed over three years and explaining a large portion (21–47%) of the phenotypic variation were found on chromosomes 5 and 6, and a further resistance QTL on chromosome 10, apparently related to foliar development, was discovered in 2016 only. In the population created with the S. pampasense source, QTLs for resistance were found in over two years on chromosomes 11 and 12. For all loci detected consistently across years, the QTLs span known R gene clusters and so they likely represent novel late blight resistance genes. Simple genetic models following the effect of the presence or absence of SNPs associated with consistently effective loci in both populations demonstrated that marker assisted selection (MAS) strategies to introgress and pyramid these loci have potential in resistance breeding strategies.

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Competition between Phytophthora infestans Effectors Leads to Increased Aggressiveness on Plants Containing Broad-Spectrum Late Blight Resistance

PLoS ONE ◽

10.1371/journal.pone.0010536 ◽

2010 ◽

Vol 5 (5) ◽

pp. e10536 ◽

Cited By ~ 40

Author(s):

Dennis A. Halterman ◽

Yu Chen ◽

Jiraphan Sopee ◽

Julio Berduo-Sandoval ◽

Amilcar Sánchez-Pérez

Keyword(s):

Late Blight ◽

Phytophthora Infestans ◽

Broad Spectrum ◽

Late Blight Resistance ◽

Blight Resistance

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Resistance to Phytophthora infestans Clonal Lineage US-23 in Potato Cultivars and Its Relationship with Early Blight Resistance and Tuber Yield

Plant Disease ◽

10.1094/pdis-03-21-0594-re ◽

2021 ◽

Author(s):

Weiya Xue ◽

Kathleen G. Haynes ◽

Xinshun Qu

Keyword(s):

Late Blight ◽

Phytophthora Infestans ◽

Early Blight ◽

Tuber Yield ◽

Late Blight Resistance ◽

Field Trials ◽

Potato Cultivars ◽

Blight Resistance ◽

Clonal Lineage ◽

Progress Curve

Resistance to late blight, caused by Phytophthora infestans clonal lineage US-23, in 217 old and modern potato cultivars was evaluated in field trials in 2016 and 2017 in Pennsylvania. Significant differences in resistance were found among these cultivars (P < 0.0001). Significant interaction between cultivars and environments was found (P < 0.0001). The values of relative area under the disease progress curve ranged from 0 to 0.5841 in 2016 and from 0 to 0.5469 in 2017. Broad-sense heritability of late blight resistance was estimated to be 0.91 with a 95% confidence interval of 0.88 to 0.93. Cluster analysis classified the cultivars into 5 groups: resistant, moderately resistant, intermediate, moderately susceptible, and susceptible. Thirty cultivars showing resistance and 32 cultivars showing moderate resistance were identified. The 217 cultivars were also evaluated for foliar maturity, tuber yield and resistance to early blight, caused by Alternaria solani. A few cultivars with late blight resistance independent of late maturity were found. Late blight resistance and early blight resistance were positively correlated, and 17 cultivars possessed resistance to both diseases. Yield tradeoff associated with late blight resistance was not observed among the cultivars in the absence of disease pressure.

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STUDIES ON FERTILITY AND LATE BLIGHT RESISTANCE IN SOLANUM BULBOCASTANUM DUN. IN MEXICO

Canadian Journal of Botany ◽

10.1139/b59-003 ◽

1959 ◽

Vol 37 (1) ◽

pp. 41-49 ◽

Cited By ~ 21

Author(s):

K. M. Graham ◽

J. S. Niederhauser ◽

Leopoldo Servin

Keyword(s):

Late Blight ◽

Phytophthora Infestans ◽

Late Blight Resistance ◽

Field Resistance ◽

Blight Resistance ◽

Solanum Bulbocastanum ◽

Mexican Isolate

Solanum balbocastanum Dun. was collected extensively throughout its range in Mexico and Guatemala. Experimental self- and cross-pollinations showed that the species is highly self-sterile and consists of cross-sterile and cross-fertile individuals. Self-sterility may be due to the presence of incompatibility factors or to triploidy. Authentic hybrids were produced between S. bulbocastanum and S. trifidum Correll, and between S. bulbocastanum and S. pinnatisectum Dun.After inoculation with race 1.2.3.4 of Phytophthora infestans three types of reaction were observed among 1148 seedlings of S. bulbocastanum: immunity with no perceptible lesions, resistance expressed by non-sporulating lesions of the hypersensitive type, and susceptibility indicated by large sporulating necrotic lesions. Seedlings resistant to an isolate of race 1.2.3.4 of Canadian origin did not always show the same level of resistance to a Mexican isolate of the same race. Varying degrees of field resistance were observed among seedling plants, while tuber-propagated plants were generally field immune. Solanum bulbocastanum is considered a mixture of resistant and susceptible genotypes.

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