scholarly journals Deciphering the Molecular Architecture of a Candidate R-gene (BjuWRR1) Product Mediating White Rust Resistance in Brassica juncea

2021 ◽  
Vol 12 (5) ◽  
pp. 393-401
Author(s):  
Chinmaya Kumar Das ◽  
◽  
Umasankar Nayak ◽  
Preetinanda Pati ◽  
Mihir Ranjan Mohanty ◽  
...  
Keyword(s):  
Brassica Juncea ◽  
Molecular Interaction ◽  
Rust Resistance ◽  
Hydrophobic Interactions ◽  
Coiled Coil ◽  
R Gene ◽  
Molecular Architecture ◽  
Three Dimensional Model ◽  
White Rust ◽  
Rust Pathogen

In this investigation, a three-dimensional model of a R-gene encoded product BjuWRR1 which is known to play a role in white rust resistance in Brassica juncea was developed to synthesize innovative ways for evolving white rust resistant cultivars. The model was built from the amino acid sequence of BjuWRR1 using structural template information of a disease resistance protein (RPP13-like protein 4 of Arabidopsis thaliana) with the help of homology-based modelling approach. Built models were validated for their stereochemical parameters and structural descriptors using Ramachandran plot analysis, protein structure analysis and ERRAT analysis. Structural analysis of BjuWRR1 model revealed that it is composed of three distinct domains namely a coiled-coil domain, a central NB-ARC nucleotide binding domain and a hypervariable leucine-rich repeat domain. Further, canonical conserved motifs such as P-loop, Kinase2-motif and HD-motif were found in the NB-ARC domain. The built model would help in understanding the molecular basis of plant-immunity against white rust pathogen by understanding the significance of inter-domain interactions in BuWRR1 in triggering the activation of downstream defense response against the white rust pathogen by promoting oligomerization of coiled-coil domains through stabilized hydrophobic interactions and interaction with NB-ARC domain. Presence of patches of charged residues in each domain of BjuWRR1 indicated their possible role in intra-molecular interaction with other domains. Therefore, this model can help in designing functional genomic studies to understand the role of intra-molecular interaction in BjuWRR1 to mediate resistance against white rust pathogen.

Validation of molecular markers for marker-assisted pyramiding of white rust resistance loci in Indian Mustard (Brassica juncea L.)

2015 ◽  
Vol 95 (5) ◽  
pp. 939-945 ◽  
Author(s):  
Binay K. Singh ◽  
Divakar Nandan ◽  
Supriya Ambawat ◽  
Bhagirath Ram ◽  
Arun Kumar ◽  
...  
Keyword(s):  
Molecular Markers ◽  
Brassica Juncea ◽  
Rust Resistance ◽  
Indian Mustard ◽  
Resistance Locus ◽  
White Rust ◽  
Pcr Products ◽  
Percent Disease Index ◽  
Different Populations

Singh, B. K., Nandan, D., Supriya, A., Ram, B., Kumar, A., Singh, T., Meena, H. S., Kumar, V., Singh, V. V., Rai, P. K. and Singh, D. 2015. Validation of molecular markers for marker-assisted pyramiding of white rust resistance loci in Indian Mustard (Brassica juncea L.). Can. J. Plant Sci. 95: 939–945. Successful application of molecular markers in marker-assisted pyramiding relies on effective determination of the target phenotype. In this respect, evaluation of the efficiency of markers for marker-assisted selection through cross-validation in different genetic backgrounds and in different populations is a crucial step. In the present study, the previously identified Arabidopsis-derived intron polymorphic (IP) markers At5g41560 and At2g36360, which were highly linked with AcB1-A4.1 and AcB1-A5.1, respectively, were validated in a set of 25 genotypes of Indian Mustard and in three different F2 populations. The relationships between the variation of PCR products of the two markers with the percent disease index (PDI) of the tested genotypes, and the co-segregation analysis of the markers with disease phenotype in F2 populations clearly indicated that At5g41560 and At2g36360 are genotype-nonspecific markers and are closely linked to white rust resistance loci AcB1-A4.1 and AcB1-A5.1, respectively. It also became evident from the present study that AcB1-A4.1 and an another white rust resistance locus Ac(2)t are likely the same gene locus.

scholarly journals Allele Characterization of Genes Required for rpg4-Mediated Wheat Stem Rust Resistance Identifies Rpg5 as the R Gene

2013 ◽  
Vol 103 (11) ◽  
pp. 1153-1161 ◽  
Author(s):  
D. Arora ◽  
T. Gross ◽  
R. Brueggeman
Keyword(s):  
Amino Acid ◽  
Stem Rust ◽  
Rust Resistance ◽  
Nucleotide Substitution ◽  
Wild Barley ◽  
Stop Codon ◽  
Stem Rust Resistance ◽  
R Gene ◽  
Wheat Stem Rust ◽  
Rust Pathogen

A highly virulent form of the wheat stem rust pathogen Puccinia graminis f. sp. tritici race TTKSK is virulent on both wheat and barley, presenting a major threat to world food security. The recessive and temperature-sensitive rpg4 gene is the only effective source of resistance identified in barley (Hordeum vulgare) against P. graminis f. sp. tritici race TTKSK. Efforts to position clone rpg4 localized resistance to a small interval on barley chromosome 5HL, tightly linked to the rye stem rust (P. graminis f. sp. secalis) resistance (R) gene Rpg5. High-resolution genetic analysis and post-transcriptional gene silencing of the genes at the rpg4/Rpg5 locus determined that three tightly linked genes (Rpg5, HvRga1, and HvAdf3) are required together for rpg4-mediated wheat stem rust resistance. Alleles of the three genes were analyzed from a diverse set of 14 domesticated barley lines (H. vulgare) and 8 wild barley accessions (H. vulgare subsp. spontaneum) to characterize diversity that may determine incompatibility (resistance). The analysis determined that HvAdf3 and HvRga1 code for predicted functional proteins that do not appear to contain polymorphisms determining the compatible (susceptible) interactions with the wheat stem rust pathogen and were expressed at the transcriptional level from both resistant and susceptible barley lines. The HvAdf3 alleles shared 100% amino acid identity among all 22 genotypes examined. The P. graminis f. sp. tritici race QCCJ-susceptible barley lines with HvRga1 alleles containing the limited amino acid substitutions unique to the susceptible varieties also contained predicted nonfunctional rpg5 alleles. Thus, susceptibility in these lines is likely due to the nonfunctional RPG5 proteins. The Rpg5 allele analysis determined that 9 of the 13 P. graminis f. sp. tritici race QCCJ-susceptible barley lines contain alleles that either code for predicted truncated proteins as the result of a single nucleotide substitution, resulting in a stop codon at amino acid 161, a single cytosine indel causing a frame shift, and a stop codon at amino acid 217, or an indel that deleted the entire STPK domain. The three P. graminis f. sp. tritici race QCCJ-susceptible lines (Swiss landraces Hv489, Hv492, and Hv611) and the wild barley accession WBDC160 contain rpg5 alleles predicted to encode full-length proteins containing a nonsynonomous nucleotide substitution that results in the amino acid substitution E1287A. This amino acid substitution present in the uncharacterized C-terminal domain is not found in any resistant line and may be important to elicit the resistance reaction. These data suggest that rpg4-mediated resistance against many wheat stem rust pathogen races, including P. graminis f. sp. tritici race TTKSK, rely on the Rpg5 R gene; thus, rpg4- and Rpg5-mediated resistance rely on a common R gene and should not be considered completely distinct. The data also determined that Rpg5 gene-specific molecular markers could be used to detect rpg4-mediated wheat stem rust resistance for marker-assisted selection.

scholarly journals A Mapped Locus on LG A6 of Brassica juncea Line Tumida Conferring Resistance to White Rust Contains a CNL Type R Gene

2020 ◽  
Vol 10 ◽  
Author(s):  
Latika Bhayana ◽  
Kumar Paritosh ◽  
Heena Arora ◽  
Satish Kumar Yadava ◽  
Priyansha Singh ◽  
...  
Keyword(s):  
Brassica Juncea ◽  
R Gene ◽  
White Rust

Molecular markers linked to white rust resistance in mustard Brassica juncea

1998 ◽  
Vol 97 (5-6) ◽  
pp. 865-870 ◽  
Author(s):  
K. V. Prabhu ◽  
D. J. Somers ◽  
G. Rakow ◽  
R. K. Gugel
Keyword(s):  
Molecular Markers ◽  
Brassica Juncea ◽  
Rust Resistance ◽  
White Rust

scholarly journals BjuWRR1, a CC-NB-LRR gene identified in Brassica juncea, confers resistance to white rust caused by Albugo Candida

2019 ◽  
Author(s):  
Heena Arora ◽  
K. Lakshmi Padmaja ◽  
Kumar Paritosh ◽  
Nitika Mukhi ◽  
A. K. Tewari ◽  
...  
Keyword(s):  
Genetic Transformation ◽  
Brassica Juncea ◽  
Gene Pool ◽  
Evolutionary Dynamics ◽  
Genomic Sequence ◽  
Oilseed Crop ◽  
R Gene ◽  
East European ◽  
Albugo Candida ◽  
White Rust

AbstractWhite rust caused by oomycete pathogen Albugo candida is a significant disease of crucifer crops including Brassica juncea (mustard), a major oilseed crop of the Indian subcontinent. Earlier a resistance-conferring locus named AcB1-A5.1 was mapped in an east European gene pool line of B. juncea – Donskaja-IV. This line was tested along with some other lines of B. juncea (AABB), B. rapa (AA) and B. nigra (BB) for resistance to six isolates of A. candida collected from different mustard growing regions of India. Donskaja-IV was found to be completely resistant to all the tested isolates. Sequencing of a BAC spanning the locus AcB1-A5.1 showed the presence of a single CC-NB-LRR protein encoding R gene. The genomic sequence of the putative R gene with its native promoter and terminator was used for the genetic transformation of a susceptible Indian gene pool line Varuna and was found to confer complete resistance to all the isolates. This is the first white rust resistance-conferring gene described from Brassica species and has been named BjuWRR1. Allelic variants of the gene in B. juncea germplasm and orthologues in the Brassicaceae genomes were studied to understand the evolutionary dynamics of the BjuWRR1 gene.HighlightBjuWRR1, a CNL type R gene, was identified from an east European gene pool line of Brassica juncea and validated for conferring resistance to white rust by genetic transformation.

Genetics of white rust resistance in Indian mustard (Brassica juncea L.) and its validation on using molecular markers

2020 ◽  
Vol 80 (03) ◽  
Author(s):  
V. V. Singh ◽  
Monika Dubey ◽  
Neeraj Gurjar ◽  
Balbeer . ◽  
Priyamedha . ◽  
...  
Keyword(s):  
Molecular Markers ◽  
Brassica Juncea ◽  
Banding Pattern ◽  
Rust Resistance ◽  
Dominant Gene ◽  
Indian Mustard ◽  
Single Dominant Gene ◽  
White Rust ◽  
Resistant Genotypes

White rust resistance loci (AcB1-A4.1 and AcB1-A5.1) associated with intron polymorphic (IP) markers i.e. At5g41560 and At2g36360, respectively, were used for validation of P1, P2, F1, F2, BC1F1 and BC2F1 generations. The donor parents namely, Bio-YSR and BEC-144 produced desired banding pattern of 430 and 750 bp while recipients viz., NRCHB 101 and DRMR-150-35 exhibited different pattern from donors confirming white rust resistance loci 4.1 and 5.1 with marker At5g41560 and At2g36360, respectively. Confirmation of these set of two IP markers in the parents and F1s lead us to further screening of selected F2, BC1F1 and BC2F1 populations. Available data on white rust reaction in different generations under study revealed that single dominant gene is responsible for white rust resistance. Potential of molecular markers in developing white rust resistant genotypes is proved under present study.

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