scholarly journals Changes in Disease Resistance Phenotypes Associated With Plant Physiological Age Are Not Caused by Variation in R Gene Transcript Abundance

2009 ◽  
Vol 22 (3) ◽  
pp. 362-368 ◽  
Author(s):  
Benjamin P. Millett ◽  
Dimitre S. Mollov ◽  
Massimo Iorizzo ◽  
Domenico Carputo ◽  
James M. Bradeen
Keyword(s):  
Disease Resistance ◽  
Late Blight ◽  
Transcript Abundance ◽  
Plant Age ◽  
Physiological Age ◽  
Blight Resistance ◽  
Gene Transcript ◽  
R Gene ◽  
Transcript Levels ◽  
Foliar Blight

Foliar late blight is one of the most important diseases of potato. Foliar blight resistance has been shown to change as a plant ages. In other pathosystems, resistance (R) gene transcript levels appear to be correlated to disease resistance. The cloning of the broad-spectrum, foliar blight resistance gene RB provided the opportunity to explore how foliar blight resistance and R-gene transcript levels vary with plant age. Plants of Solanum bulbocastanum PT29, from which RB, including the native promoter and other flanking regions, was cloned, and S. tuberosum cv. Dark Red Norland (nontransformed and RB-transformed) representing three different developmental stages were screened for resistance to late blight and RB transcript levels. Preflowering plants of all genotypes exhibited the highest levels of resistance, followed by postflowering and near-senescing plants. The RB transgene significantly affected resistance, enhancing resistance levels of all RB-containing lines, especially in younger plants. RB transgene transcripts were detected at all plant ages, despite weak correlation with disease resistance. Consistent transcript levels in plants of different physiological ages with variable levels of disease resistance demonstrate that changes in disease-resistance phenotypes associated with plant age cannot be attributed to changes in R-gene transcript abundance.

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

2009 ◽  
Vol 22 (4) ◽  
pp. 437-446 ◽  
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.

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

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.

scholarly journals The Late Blight Resistance Locus Rpi-blb3 from Solanum bulbocastanum Belongs to a Major Late Blight R Gene Cluster on Chromosome 4 of Potato

2005 ◽  
Vol 18 (7) ◽  
pp. 722-729 ◽  
Author(s):  
Tae-Ho Park ◽  
Jack Gros ◽  
Anne Sikkema ◽  
Vivianne G. A. A. Vleeshouwers ◽  
Marielle Muskens ◽  
...  
Keyword(s):  
Late Blight ◽  
Gene Cluster ◽  
Late Blight Resistance ◽  
Gene Clusters ◽  
Blight Resistance ◽  
Resistance Locus ◽  
R Gene ◽  
Chromosome 4 ◽  
Solanum Bulbocastanum ◽  
Wild Potato Species

Late blight, caused by Phytophthora infestans, is one of the most devastating diseases in cultivated potato. Breeding of new potato cultivars with high levels of resistance to P. infestans is considered the most durable strategy for future potato cultivation. In this study, we report the identification of a new late-blight resistance (R) locus from the wild potato species Solanum bulbocastanum. Using several different approaches, a high-resolution genetic map of the new locus was generated, delimiting Rpi-blb3 to a 0.93 cM interval on chromosome 4. One amplification fragment length polymorphism marker was identified that cosegregated in 1,396 progeny plants of an intraspecific mapping population with Rpi-blb3. For comparative genomics purposes, markers linked to Rpi-blb3 were tested in mapping populations used to map the three other late-blight R loci Rpi-abpt, R2, and R2-like also to chromosome 4. Marker order and allelic conservation suggest that Rpi-blb3, Rpiabpt, R2, and R2-like reside in the same R gene cluster on chromosome 4 and likely belong to the same gene family. Our findings provide novel insights in the evolution of R gene clusters conferring late-blight resistance in Solanum spp.

scholarly journals Leaf Position Prevails Over Plant Age and Leaf Age in Reflecting Resistance to Late Blight in Potato

2003 ◽  
Vol 93 (6) ◽  
pp. 666-674 ◽  
Author(s):  
M. H. P. W. Visker ◽  
L. C. P. Keizer ◽  
D. J. Budding ◽  
L. C. Van Loon ◽  
L. T. Colon ◽  
...  
Keyword(s):  
Late Blight ◽  
Leaf Age ◽  
Late Blight Resistance ◽  
Plant Age ◽  
Blight Resistance ◽  
Controlled Environment ◽  
General Effect ◽  
Leaf Position ◽  
Nonspecific Resistance ◽  
Growing Conditions

The effects of plant age, leaf age, and leaf position on race-nonspecific resistance against Phytophthora infestans were investigated in a series of field and controlled environment experiments with five different potato (Solanum tuberosum) cultivars. Leaf position proved to be the most significant factor; apical leaves were far more resistant to late blight than basal leaves. Plant age and leaf age had only minor effects; therefore, the resistance of a specific leaf remained about the same during its entire lifetime. The gradual increase in late blight resistance from basal leaves to apical leaves appeared to be a general effect, irrespective of cultivar, growing conditions, or resistance test. Therefore, it is important to consider leaf position in tests for late blight resistance, because contrasts in resistance may be ascribed erroneously to differences between genotypes or treatments, whereas they are actually caused by differences in leaf position.

scholarly journals Potato Tuber Blight Resistance Phenotypes Correlate with RB Transgene Transcript Levels in an Age-Dependent Manner

2015 ◽  
Vol 105 (8) ◽  
pp. 1131-1136 ◽  
Author(s):  
Benjamin P. Millett ◽  
Liangliang Gao ◽  
Massimo Iorizzo ◽  
Domenico Carputo ◽  
James M. Bradeen
Keyword(s):  
Late Blight ◽  
Late Blight Resistance ◽  
Blight Resistance ◽  
Dependent Manner ◽  
Transcript Levels ◽  
Tuber Resistance ◽  
Age Dependent ◽  
Organ Specific ◽  
Late Blight Disease ◽  
Blight Disease

Plants have evolved strategies and mechanisms to detect and respond to pathogen attack. Different organs of the same plant may be subjected to different environments (e.g., aboveground versus belowground) and pathogens with different lifestyles. Accordingly, plants commonly need to tailor defense strategies in an organ-specific manner. Phytophthora infestans, causal agent of potato late blight disease, infects both aboveground foliage and belowground tubers. We examined the efficacy of transgene RB (known for conferring foliar late blight resistance) in defending against tuber late blight disease. Our results indicate that the presence of the transgene has a positive yet only marginally significant effect on tuber disease resistance on average. However, a significant association between transgene transcript levels and tuber resistance was established for specific transformed lines in an age-dependent manner, with higher transcript levels indicating enhanced tuber resistance. Thus, RB has potential to function in both foliage and tuber to impart late blight resistance. Our data suggest that organ-specific resistance might result directly from transcriptional regulation of the resistance gene itself.

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

2020 ◽  
Vol 110 (8) ◽  
pp. 1375-1387
Author(s):  
Jiayi Zheng ◽  
Shaoguang Duan ◽  
Miles R. Armstrong ◽  
Yanfeng Duan ◽  
Jianfei Xu ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Late Blight ◽  
Phytophthora Infestans ◽  
Resistance Genes ◽  
Resistance Mechanism ◽  
Late Blight Resistance ◽  
Blight Resistance ◽  
Resistance Response ◽  
Potato Disease ◽  
New Findings

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.

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

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.

Correlation Between Transcript Abundance of the RB Gene and the Level of the RB-Mediated Late Blight Resistance in Potato

2009 ◽  
Vol 22 (4) ◽  
pp. 447-455 ◽  
Author(s):  
Lara C. Kramer ◽  
Mallory J. Choudoir ◽  
Susan M. Wielgus ◽  
Pudota B. Bhaskar ◽  
Jiming Jiang
Keyword(s):  
Late Blight ◽  
Late Blight Resistance ◽  
Transcript Abundance ◽  
Blight Resistance ◽  
Solanum Bulbocastanum ◽  
Pathogen Infection ◽  
Wild Potato Species ◽  
Transgenic Lines ◽  
Rb Gene ◽  
High Level

Numerous disease-resistance genes have been cloned and characterized in various plant species. Only a few of these reported genes were transcriptionally induced or had enhanced transcription upon pathogen infection. Here, we report that transcription of the RB gene, which was cloned from the wild potato species Solanum bulbocastanum and confers resistance to potato late blight, was significantly increased after inoculation with the late blight pathogen Phytophthora infestans. Different RB transgenic lines showed different levels of resistance, which were correlated with the amounts of RB transcript in the transgenic plants. Different transgenic lines also showed different patterns of RB transcription 1, 3, and 5 days after P. infestans inoculation. Interestingly, the RB gene showed a higher basal level of transcription and a more dramatic transcriptional increase upon inoculation in S. bulbocastanum than in all potato transgenic lines. Our results revealed a predictive correlation between transcript abundance of the RB gene and the level of the RB-mediated late blight resistance. High level of resistance was associated with a combination of rapid RB transcript induction immediately after pathogen infection followed by the steady production of RB transcript. Thus, the transcription level of the RB gene provides a valuable marker for selecting and deploying RB-containing potato lines for late blight control.

Identification and functional characterisation of late blight resistance polymorphic genes in Russet Burbank potato cultivar

2021 ◽  
Vol 48 (1) ◽  
pp. 88 ◽  
Author(s):  
Niranjan Hegde ◽  
Dadakhalandar Doddamani ◽  
Ajjamada C. Kushalappa
Keyword(s):  
Disease Resistance ◽  
Late Blight ◽  
Potato Cultivar ◽  
Late Blight Resistance ◽  
Vital Role ◽  
Russet Burbank ◽  
Blight Resistance ◽  
Nucleotide Polymorphisms ◽  
Protein Coding ◽  
Functional Characterisation

In plants, the biosynthesis of the phenylpropanoid, flavonoid and fatty acid pathway monomers, polymers and conjugated metabolites play a vital role in disease resistance. These are generally deposited to reinforce cell walls to contain the pathogen to the site of infection. Identification of sequence variants in genes that biosynthesise these resistance metabolites can explain the mechanisms of disease resistance. The resistant and susceptible genotypes inoculated with Phytophthora infestans were RNA sequenced to identify the single nucleotide polymorphisms (SNPs) and insertion/deletion (InDel) variations. The SNPs/InDels were annotated and classified into different categories based on their effect on gene functions. In the selected 25 biosynthetic genes overlapping 39 transcripts, a total of 52 SNPs/InDels were identified in the protein-coding (CDS) regions. These were categorised as deleterious based on prediction of their effects on protein structure and function. The SNPs/InDels data obtained in this study can be used in genome editing to enhance late blight resistance in Russet Burbank and other potato cultivars.

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