scholarly journals In-silico identification and differential expression of putative disease resistance-related genes within the collinear region of Brassica napus blackleg resistance locus LepR2’ in Brassica oleracea

2020 ◽  
Vol 61 (5) ◽  
pp. 879-890 ◽  
Author(s):  
Mohammad Rashed Hossain ◽  
Mostari Jahan Ferdous ◽  
Jong-In Park ◽  
Arif Hasan Khan Robin ◽  
Sathishkumar Natarajan ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Brassica Napus ◽  
Resistance Locus ◽  
R Gene ◽  
R Genes ◽  
Blackleg Resistance ◽  
B Genome ◽  
Expression Of Genes ◽  
C Genome ◽  
R Loci

Abstract Blackleg disease, caused by Leptosphaeria maculans, greatly affects the production of cabbage (Brassica oleracea). However, definitive R-gene(s) are yet to be identified in this crop. In contrast, a number of R-loci have been identified in A- or B-genome crops. Identification of few resistant cabbage genotypes indicates the presence of R-genes in this C-genome crop. High ancestral synteny between Brassica genomes suggests that the collinear regions of known A- or B-genome R-loci may also contain functional R-genes in the C-genome. Strong resistance was observed in the cotyledons of cabbage inbred line SCNU-98 against two L. maculans isolates, 03–02 s and 00–100 s. We investigated the collinear region of the Brassica napus blackleg resistance locus LepR2’ in B. oleracea since both isolates of L. maculans contain corresponding avirulence genes. The locus was collinear to a 5.8 Mbp genomic segment of B. oleracea chromosome C09 containing 13 genes that have putative disease resistance-related domains. High expression of genes Bo9g117290 and Bo9g111510 against isolate 00–100 s, and high expression of genes Bo9g126150 and Bo9g111490 against both isolates in the resistant-line SCNU-98 indicate their putative roles in blackleg resistance, which remained to be functionally verified. This work enhances our understanding of R-gene-mediated resistance to blackleg in cabbage.

scholarly journals Recent Findings Unravel Genes and Genetic Factors Underlying Leptosphaeria maculans Resistance in Brassica napus and Its Relatives

2020 ◽  
Vol 22 (1) ◽  
pp. 313
Author(s):  
Aldrin Y. Cantila ◽  
Nur Shuhadah Mohd Saad ◽  
Junrey C. Amas ◽  
David Edwards ◽  
Jacqueline Batley
Keyword(s):  
Brassica Napus ◽  
Genetic Factors ◽  
Quantitative Resistance ◽  
Genetic Resistance ◽  
Leptosphaeria Maculans ◽  
Gene Interaction ◽  
R Gene ◽  
R Genes ◽  
Blackleg Resistance ◽  
Avr Gene

Among the Brassica oilseeds, canola (Brassica napus) is the most economically significant globally. However, its production can be limited by blackleg disease, caused by the fungal pathogen Lepstosphaeria maculans. The deployment of resistance genes has been implemented as one of the key strategies to manage the disease. Genetic resistance against blackleg comes in two forms: qualitative resistance, controlled by a single, major resistance gene (R gene), and quantitative resistance (QR), controlled by numerous, small effect loci. R-gene-mediated blackleg resistance has been extensively studied, wherein several genomic regions harbouring R genes against L. maculans have been identified and three of these genes were cloned. These studies advance our understanding of the mechanism of R gene and pathogen avirulence (Avr) gene interaction. Notably, these studies revealed a more complex interaction than originally thought. Advances in genomics help unravel these complexities, providing insights into the genes and genetic factors towards improving blackleg resistance. Here, we aim to discuss the existing R-gene-mediated resistance, make a summary of candidate R genes against the disease, and emphasise the role of players involved in the pathogenicity and resistance. The comprehensive result will allow breeders to improve resistance to L. maculans, thereby increasing yield.

Arabidopsis thaliana: A source of candidate disease-resistance genes for Brassica napus

Genome ◽  
2000 ◽  
Vol 43 (3) ◽  
pp. 452-460 ◽  
Author(s):  
D Sillito ◽  
I AP Parkin ◽  
R Mayerhofer ◽  
D J Lydiate ◽  
A G Good
Keyword(s):  
Arabidopsis Thaliana ◽  
Disease Resistance ◽  
Brassica Napus ◽  
Resistance Genes ◽  
Plant Disease Resistance ◽  
Disease Resistance Genes ◽  
R Gene ◽  
R Genes ◽  
Rapid Divergence ◽  
Genomic Regions

Common structural and amino acid motifs among cloned plant disease-resistance genes (R genes), have made it possible to identify putative disease-resistance sequences based on DNA sequence identity. Mapping of such R-gene homologues will identify candidate disease-resistance loci to expedite map-based cloning strategies in complex crop genomes. Arabidopsis thaliana expressed sequence tags (ESTs) with homology to cloned plant R genes (R-ESTs), were mapped in both A. thaliana and Brassica napus to identify candidate R-gene loci and investigate intergenomic collinearity. Brassica R-gene homologous sequences were also mapped in B. napus. In total, 103 R-EST loci and 36 Brassica R-gene homologous loci were positioned on the N-fo-61-9 B. napus genetic map, and 48 R-EST loci positioned on the Columbia × Landsberg A. thaliana map. The mapped loci identified collinear regions between Arabidopsis and Brassica which had been observed in previous comparative mapping studies; the detection of syntenic genomic regions indicated that there was no apparent rapid divergence of the identified genomic regions housing the R-EST loci.Key words: RFLP mapping, candidate R genes, R-gene homologues, genomic collinearity, Arabidopsis ESTs.

scholarly journals Status and advances in mining for blackleg (Leptosphaeria maculans) quantitative resistance (QR) in oilseed rape (Brassica napus)

2021 ◽  
Author(s):  
Junrey Amas ◽  
Robyn Anderson ◽  
David Edwards ◽  
Wallace Cowling ◽  
Jacqueline Batley
Keyword(s):  
Brassica Napus ◽  
Oilseed Rape ◽  
Quantitative Resistance ◽  
Crop Improvement ◽  
Leptosphaeria Maculans ◽  
R Gene ◽  
R Genes ◽  
Blackleg Resistance ◽  
Linkage And Association Analysis ◽  
Breeding Programmes

Abstract Key message Quantitative resistance (QR) loci discovered through genetic and genomic analyses are abundant in the Brassica napus genome, providing an opportunity for their utilization in enhancing blackleg resistance. Abstract Quantitative resistance (QR) has long been utilized to manage blackleg in Brassica napus (canola, oilseed rape), even before major resistance genes (R-genes) were extensively explored in breeding programmes. In contrast to R-gene-mediated qualitative resistance, QR reduces blackleg symptoms rather than completely eliminating the disease. As a polygenic trait, QR is controlled by numerous genes with modest effects, which exerts less pressure on the pathogen to evolve; hence, its effectiveness is more durable compared to R-gene-mediated resistance. Furthermore, combining QR with major R-genes has been shown to enhance resistance against diseases in important crops, including oilseed rape. For these reasons, there has been a renewed interest among breeders in utilizing QR in crop improvement. However, the mechanisms governing QR are largely unknown, limiting its deployment. Advances in genomics are facilitating the dissection of the genetic and molecular underpinnings of QR, resulting in the discovery of several loci and genes that can be potentially deployed to enhance blackleg resistance. Here, we summarize the efforts undertaken to identify blackleg QR loci in oilseed rape using linkage and association analysis. We update the knowledge on the possible mechanisms governing QR and the advances in searching for the underlying genes. Lastly, we lay out strategies to accelerate the genetic improvement of blackleg QR in oilseed rape using improved phenotyping approaches and genomic prediction tools.

scholarly journals Disease Resistance Genetics and Genomics in Octoploid Strawberry

2019 ◽  
Vol 9 (10) ◽  
pp. 3315-3332 ◽  
Author(s):  
Christopher R. Barbey ◽  
Seonghee Lee ◽  
Sujeet Verma ◽  
Kevin A. Bird ◽  
Alan E. Yocca ◽  
...  
Keyword(s):  
Disease Resistance ◽  
A Priori ◽  
Eqtl Analysis ◽  
R Gene ◽  
R Genes ◽  
Specialty Crop ◽  
Crop Disease ◽  
Strawberry Cultivar ◽  
Gene Collection ◽  
Resistance Genetics

Octoploid strawberry (Fragaria ×ananassa) is a valuable specialty crop, but profitable production and availability are threatened by many pathogens. Efforts to identify and introgress useful disease resistance genes (R-genes) in breeding programs are complicated by strawberry’s complex octoploid genome. Recently-developed resources in strawberry, including a complete octoploid reference genome and high-resolution octoploid genotyping, enable new analyses in strawberry disease resistance genetics. This study characterizes the complete R-gene collection in the genomes of commercial octoploid strawberry and two diploid ancestral relatives, and introduces several new technological and data resources for strawberry disease resistance research. These include octoploid R-gene transcription profiling, dN/dS analysis, expression quantitative trait loci (eQTL) analysis and RenSeq analysis in cultivars. Octoploid fruit eQTL were identified for 76 putative R-genes. R-genes from the ancestral diploids Fragaria vesca and Fragaria iinumae were compared, revealing differential inheritance and retention of various octoploid R-gene subtypes. The mode and magnitude of natural selection of individual F. ×ananassa R-genes was also determined via dN/dS analysis. R-gene sequencing using enriched libraries (RenSeq) has been used recently for R-gene discovery in many crops, however this technique somewhat relies upon a priori knowledge of desired sequences. An octoploid strawberry capture-probe panel, derived from the results of this study, is validated in a RenSeq experiment and is presented for community use. These results give unprecedented insight into crop disease resistance genetics, and represent an advance toward exploiting variation for strawberry cultivar improvement.

Molecular cytogenetic identification of B genome chromosomes linked to blackleg disease resistance in Brassica napus × B. carinata interspecific hybrids

2014 ◽  
Vol 127 (6) ◽  
pp. 1305-1318 ◽  
Author(s):  
Rudolph Fredua-Agyeman ◽  
Olivier Coriton ◽  
Virginie Huteau ◽  
Isobel A. P. Parkin ◽  
Anne-Marie Chèvre ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Brassica Napus ◽  
Interspecific Hybrids ◽  
Blackleg Disease ◽  
Molecular Cytogenetic ◽  
B Genome

Identification and mapping of a third blackleg resistance locus in Brassica napus derived from B. rapa subsp. sylvestris

Genome ◽  
2008 ◽  
Vol 51 (1) ◽  
pp. 64-72 ◽  
Author(s):  
Fengqun Yu ◽  
Derek J. Lydiate ◽  
S. Roger Rimmer
Keyword(s):  
Brassica Napus ◽  
Linkage Group ◽  
Resistance Gene ◽  
Leptosphaeria Maculans ◽  
Resistance Locus ◽  
Dominant Allele ◽  
Breeding Lines ◽  
Disease Reaction ◽  
Blackleg Resistance ◽  
Map Location

The spectrum of resistance to isolates of Leptosphaeria maculans and the map location of a new blackleg resistance gene found in the canola cultivar Brassica napus ‘Surpass 400’ are described. Two blackleg resistance genes, LepR1 and LepR2, from B. rapa subsp. sylvestris and introgressed in B. napus were identified previously. ‘Surpass 400’ also has blackleg resistance introgressed from B. rapa subsp. sylvestris. Using 31 diverse isolates of L. maculans, the disease reaction of ‘Surpass 400’ was compared with those of the resistant breeding lines AD9 (which contains LepR1), AD49 (which contains LepR2), and MC1-8 (which contains both LepR1 and LepR2). The disease reaction on ‘Surpass 400’ was different from those observed on AD9 and MC1-8, indicating that ‘Surpass 400’ carries neither LepR1 nor both LepR1 and LepR2 in combination. Disease reactions of ‘Surpass 400’ to most of the isolates tested were indistinguishable from those of AD49, which suggested ‘Surpass 400’ might contain LepR2 or a similar resistance gene. Classical genetic analysis of F1 and BC1 plants showed that a dominant allele conferred resistance to isolates of L. maculans in ‘Surpass 400’. The resistance gene, which mapped to B. napus linkage group N10 in an interval of 2.9 cM flanked by microsatellite markers sR12281a and sN2428Rb and 11.7 cM below LepR2, was designated LepR3. A 9 cM region of the B. napus genome containing LepR3 was found to be syntenic with a segment of Arabidopsis chromosome 5.

Identification and mapping of a novel blackleg resistance locus LepR4 in the progenies from Brassica napus × B. rapa subsp. sylvestris

2012 ◽  
Vol 126 (2) ◽  
pp. 307-315 ◽  
Author(s):  
Fengqun Yu ◽  
Richard K. Gugel ◽  
H. Randy Kutcher ◽  
Gary Peng ◽  
S. Roger Rimmer
Keyword(s):  
Brassica Napus ◽  
Resistance Locus ◽  
Blackleg Resistance

scholarly journals The Genetic Architecture of Disease Resistance in Maize: A Synthesis of Published Studies

2006 ◽  
Vol 96 (2) ◽  
pp. 120-129 ◽  
Author(s):  
Randall J. Wisser ◽  
Peter J. Balint-Kurti ◽  
Rebecca J. Nelson
Keyword(s):  
Disease Resistance ◽  
Genetic Architecture ◽  
Visual Inspection ◽  
Statistical Tests ◽  
R Gene ◽  
R Genes ◽  
Consensus Map ◽  
Maize Germplasm ◽  
Genome Wide ◽  
Breeding Schemes

Fifty publications on the mapping of maize disease resistance loci were synthesized. These papers reported the locations of 437 quantitative trait loci (QTL) for disease (dQTL), 17 resistance genes (R-genes), and 25 R-gene analogs. A set of rules was devised to enable the placement of these loci on a single consensus map, permitting analysis of the distribution of resistance loci identified across a variety of maize germplasm for a number of different diseases. The confidence intervals of the dQTL were distributed over all 10 chromosomes and covered 89% of the genetic map to which the data were anchored. Visual inspection indicated the presence of clusters of dQTL for multiple diseases. Clustering of dQTL was supported by statistical tests that took into account genome-wide variations in gene density. Several novel clusters of resistance loci were identified. Evidence was also found for the association of dQTL with maturity-related QTL. It was evident from the distinct dQTL distributions for the different diseases that certain breeding schemes may be more suitable for certain diseases. This review provides an up-to-date synthesis of reports on the locations of resistance loci in maize.

scholarly journals Disease Resistance Genetics and Genomics in Octoploid Strawberry

2019 ◽  
Author(s):  
Christopher Barbey ◽  
Seonghee Lee ◽  
Sujeet Verma ◽  
Kevin A. Bird ◽  
Alan E. Yocca ◽  
...  
Keyword(s):  
Disease Resistance ◽  
A Priori ◽  
Eqtl Analysis ◽  
R Gene ◽  
R Genes ◽  
Specialty Crop ◽  
Crop Disease ◽  
Strawberry Cultivar ◽  
Gene Collection ◽  
Resistance Genetics

ABSTRACTOctoploid strawberry (Fragaria × ananassa) is a valuable specialty crop, but profitable production and availability are threatened by many pathogens. Efforts to identify and introgress useful disease resistance genes (R-genes) in breeding programs are complicated by strawberry’s complex octoploid genome. Recently-developed resources in strawberry, including a complete octoploid reference genome and high-resolution octoploid genotyping, enable new analyses in strawberry disease resistance genetics. This study characterizes the complete R-gene collection in the genomes of commercial octoploid strawberry and two diploid ancestral relatives, and introduces several new technological and data resources for strawberry disease resistance research. These include octoploid R-gene transcription profiling, dN/dS analysis, eQTL analysis and RenSeq analysis in cultivars. Octoploid fruit transcript expression quantitative trait loci (eQTL) were identified for 77 putative R-genes. R-genes from the ancestral diploids Fragaria vesca and Fragaria iinumae were compared, revealing differential inheritance and retention of various octoploid R-gene subtypes. The mode and magnitude of natural selection of individual F. × ananassa R-genes was also determined via dN/dS analysis. R-gene sequencing using enriched libraries (RenSeq) has been used recently for R-gene discovery in many crops, however this technique somewhat relies upon a priori knowledge of desired sequences. An octoploid strawberry capture-probe panel, derived from the results of this study, is validated in a RenSeq experiment and is presented for community use. These results give unprecedented insight into crop disease resistance genetics, and represent an advance towards exploiting variation for strawberry cultivar improvement.

scholarly journals Interactive Regulation of Hormone and Resistance Gene in Proline Metabolism Is Involved in Effector-Triggered Immunity or Disease Susceptibility in the Xanthomonas campestris pv. campestris–Brassica napus Pathosystem

2022 ◽  
Vol 12 ◽  
Author(s):  
Md Al Mamun ◽  
Md Tabibul Islam ◽  
Bok-Rye Lee ◽  
Dong-Won Bae ◽  
Tae-Hwan Kim
Keyword(s):  
Brassica Napus ◽  
Binding Site ◽  
Xanthomonas Campestris ◽  
Disease Susceptibility ◽  
Proline Accumulation ◽  
R Gene ◽  
R Genes ◽  
Proline Metabolism ◽  
Leucine Rich Repeat ◽  
Effector Triggered Immunity

To characterize cultivar variations in hormonal regulation of the transition between pattern-triggered immunity (PTI) and effector-triggered immunity or susceptibility (ETI or ETS), the responses of resistance (R-) genes, hydrogen peroxide, and proline metabolism in two Brassica napus cultivars to contrasting disease susceptibility (resistant cv. Capitol vs. susceptible cv. Mosa) were interpreted as being linked to those of endogenous hormonal levels and signaling genes based on a time course of disease symptom development. Disease symptoms caused by the Xanthomonas campestris pv. campestris (Xcc) infections were much more developed in cv. Mosa than in cv. Capitol, as shown by an earlier appearance (at 3 days postinoculation [3 DPI]) and larger V-shaped necrosis lesions (at 9–15 DPI) in cv. Mosa. The cultivar variations in the R-genes, hormone status, and proline metabolism were found in two different phases (early [0–3 DPI] and later [9–15 DPI]). In the early phase, Xcc significantly upregulated PTI-related cytoplasmic kinase (Botrytis-induced kinase-1 [BIK1]) expression (+6.3-fold) with salicylic acid (SA) accumulation in cv. Capitol, while relatively less (+2.6-fold) with highly increased jasmonic acid (JA) level in cv. Mosa. The Xcc-responsive proline accumulation in both cultivars was similar to upregulated expression of proline synthesis-related genes (P5CS2 and P5CR). During the later phase in cv. Capitol, Xcc-responsive upregulation of ZAR1 (a coiled-coil-nucleotide binding site-leucine-rich repeat [CC-NB-LRR-type R-gene]) was concomitant with a gradual increase in JA levels without additional proline accumulation. However, in cv. Mosa, upregulation of TAO1 (a toll/interleukin-1 receptor-nucleotide binding site-leucine-rich repeat [TIR-NB-LRR-type R-gene]) was consistent with an increase in SA and abscisic acid (ABA) levels and resulted in an antagonistic depression of JA, which led to a proline accumulation. These results indicate that Xcc-induced BIK1- and ZAR1-mediated JA signaling interactions provide resistance and confirm ETI, whereas BIK1- and TAO1-enhanced SA- and/or ABA-mediated proline accumulation is associated with disease susceptibility (ETS).

Sign in / Sign up

Export Citation Format

Share Document