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Arora H, Padmaja KL, Paritosh K, Mukhi N, Tewari AK, Mukhopadhyay A, Gupta V, Pradhan AK, Pental D. BjuWRR1, a CC-NB-LRR gene identified in Brassica juncea, confers resistance to white rust caused by Albugo candida. Theor Appl Genet 2019; 132:2223-2236. [PMID: 31049632 DOI: 10.1007/s00122-019-03350-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Accepted: 04/20/2019] [Indexed: 05/28/2023]
Abstract
BjuWRR1, 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. White rust caused by the 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.
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Affiliation(s)
- Heena Arora
- Department of Genetics, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India
| | - K Lakshmi Padmaja
- Centre for Genetic Manipulation of Crop Plants, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India
| | - Kumar Paritosh
- Centre for Genetic Manipulation of Crop Plants, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India
| | - Nitika Mukhi
- Department of Genetics, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India
| | - A K Tewari
- Department of Plant Pathology, Govind Ballabh Pant University of Agriculture and Technology, Udham Singh Nagar, Pantnagar, Uttarakhand, 263145, India
| | - Arundhati Mukhopadhyay
- Centre for Genetic Manipulation of Crop Plants, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India
| | - Vibha Gupta
- Centre for Genetic Manipulation of Crop Plants, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India
| | - Akshay K Pradhan
- Department of Genetics, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India
- Centre for Genetic Manipulation of Crop Plants, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India
| | - Deepak Pental
- Centre for Genetic Manipulation of Crop Plants, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India.
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Sharma S, Padmaja KL, Gupta V, Paritosh K, Pradhan AK, Pental D. Two plastid DNA lineages--Rapa/Oleracea and Nigra--within the tribe Brassiceae can be best explained by reciprocal crosses at hexaploidy: evidence from divergence times of the plastid genomes and R-block genes of the A and B genomes of Brassica juncea. PLoS One 2014; 9:e93260. [PMID: 24691069 PMCID: PMC3972200 DOI: 10.1371/journal.pone.0093260] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Accepted: 03/04/2014] [Indexed: 12/23/2022] Open
Abstract
Brassica species (tribe Brassiceae) belonging to U's triangle--B. rapa (AA), B. nigra (BB), B. oleracea (CC), B. juncea (AABB), B. napus (AACC) and B. carinata (BBCC)--originated via two polyploidization rounds: a U event producing the three allopolyploids, and a more ancient b genome-triplication event giving rise to the A-, B-, and C-genome diploid species. Molecular mapping studies, in situ hybridization, and genome sequencing of B. rapa support the genome triplication origin of tribe Brassiceae, and suggest that these three diploid species diversified from a common hexaploid ancestor. Analysis of plastid DNA has revealed two distinct lineages--Rapa/Oleracea and Nigra--that conflict with hexaploidization as a single event defining the tribe Brassiceae. We analysed an R-block region of A. thaliana present in six copies in B. juncea (AABB), three copies each on A- and B-genomes to study gene fractionation pattern and synonymous base substitution rates (Ks values). Divergence time of paralogues within the A and B genomes and homoeologues between the A and B genomes was estimated. Homoeologous R blocks of the A and B genomes exhibited high gene collinearity and a conserved gene fractionation pattern. The three progenitors of diploid Brassicas were estimated to have diverged approximately 12 mya. Divergence of B. rapa and B. nigra, calculated from plastid gene sequences, was estimated to have occurred approximately 12 mya, coinciding with the divergence of the three genomes participating in the b event. Divergence of B. juncea A and B genome homoeologues was estimated to have taken place around 7 mya. Based on divergence time estimates and the presence of distinct plastid lineages in tribe Brassiceae, it is concluded that at least two independent triplication events involving reciprocal crosses at the time of the b event have given rise to Rapa/Oleracea and Nigra lineages.
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Affiliation(s)
- Sarita Sharma
- Centre for Genetic Manipulation of Crop Plants, University of Delhi South Campus, New Delhi, India
| | - K. Lakshmi Padmaja
- Centre for Genetic Manipulation of Crop Plants, University of Delhi South Campus, New Delhi, India
| | - Vibha Gupta
- Centre for Genetic Manipulation of Crop Plants, University of Delhi South Campus, New Delhi, India
| | - Kumar Paritosh
- Centre for Genetic Manipulation of Crop Plants, University of Delhi South Campus, New Delhi, India
| | - Akshay K. Pradhan
- Centre for Genetic Manipulation of Crop Plants, University of Delhi South Campus, New Delhi, India
- Department of Genetics, University of Delhi South Campus, New Delhi, India
| | - Deepak Pental
- Centre for Genetic Manipulation of Crop Plants, University of Delhi South Campus, New Delhi, India
- Department of Genetics, University of Delhi South Campus, New Delhi, India
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Panjabi P, Jagannath A, Bisht NC, Padmaja KL, Sharma S, Gupta V, Pradhan AK, Pental D. Comparative mapping of Brassica juncea and Arabidopsis thaliana using Intron Polymorphism (IP) markers: homoeologous relationships, diversification and evolution of the A, B and C Brassica genomes. BMC Genomics 2008; 9:113. [PMID: 18315867 PMCID: PMC2277410 DOI: 10.1186/1471-2164-9-113] [Citation(s) in RCA: 124] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2007] [Accepted: 03/03/2008] [Indexed: 11/25/2022] Open
Abstract
Background Extensive mapping efforts are currently underway for the establishment of comparative genomics between the model plant, Arabidopsis thaliana and various Brassica species. Most of these studies have deployed RFLP markers, the use of which is a laborious and time-consuming process. We therefore tested the efficacy of PCR-based Intron Polymorphism (IP) markers to analyze genome-wide synteny between the oilseed crop, Brassica juncea (AABB genome) and A. thaliana and analyzed the arrangement of 24 (previously described) genomic block segments in the A, B and C Brassica genomes to study the evolutionary events contributing to karyotype variations in the three diploid Brassica genomes. Results IP markers were highly efficient and generated easily discernable polymorphisms on agarose gels. Comparative analysis of the segmental organization of the A and B genomes of B. juncea (present study) with the A and B genomes of B. napus and B. nigra respectively (described earlier), revealed a high degree of colinearity suggesting minimal macro-level changes after polyploidization. The ancestral block arrangements that remained unaltered during evolution and the karyotype rearrangements that originated in the Oleracea lineage after its divergence from Rapa lineage were identified. Genomic rearrangements leading to the gain or loss of one chromosome each between the A-B and A-C lineages were deciphered. Complete homoeology in terms of block organization was found between three linkage groups (LG) each for the A-B and A-C genomes. Based on the homoeology shared between the A, B and C genomes, a new nomenclature for the B genome LGs was assigned to establish uniformity in the international Brassica LG nomenclature code. Conclusion IP markers were highly effective in generating comparative relationships between Arabidopsis and various Brassica species. Comparative genomics between the three Brassica lineages established the major rearrangements, translocations and fusions pivotal to karyotype diversification between the A, B and C genomes of Brassica species. The inter-relationships established between the Brassica lineages vis-à-vis Arabidopsis would facilitate the identification and isolation of candidate genes contributing to traits of agronomic value in crop Brassicas and the development of unified tools for Brassica genomics.
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Affiliation(s)
- Priya Panjabi
- Centre for Genetic Manipulation of Crop Plants, University of Delhi South Campus, Benito Juarez Road, New Delhi 110021, India.
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Ramchiary N, Padmaja KL, Sharma S, Gupta V, Sodhi YS, Mukhopadhyay A, Arumugam N, Pental D, Pradhan AK. Mapping of yield influencing QTL in Brassica juncea: implications for breeding of a major oilseed crop of dryland areas. Theor Appl Genet 2007; 115:807-17. [PMID: 17646960 DOI: 10.1007/s00122-007-0610-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2006] [Accepted: 07/07/2007] [Indexed: 05/16/2023]
Abstract
Quantitative trait loci (QTL) analysis of yield influencing traits was carried out in Brassica juncea (AABB) using a doubled haploid (DH) mapping population of 123 lines derived from a cross between Varuna (a line representing the Indian gene pool) and Heera (representing the east European gene pool) to identify potentially useful alleles from both the parents. The existing AFLP based map of B. juncea was further saturated with RFLP and SSR markers which led to the identification of the linkage groups belonging to the A (B. rapa) and B (B. nigra) genome components of B. juncea. For QTL dissection, the DH lines were evaluated at three different environments and phenotyped for 12 quantitative traits. A total of 65 QTL spread over 13 linkage groups (LG) were identified from the three environments. QTL analysis showed that the A genome has contributed more than the B genome to productivity (68% of the total QTL detected) suggesting a more prominent role of the A genome towards domestication of this crop. The east European line, Heera, carried favorable alleles for 42% of the detected QTL and the remaining 58% were in the Indian gene pool line, Varuna. We observed clustering of major QTL in a few linkage groups, particularly in J7 and J10 of the A genome, with QTL of different traits having agronomically antagonistic allelic effects co-mapping to the same genetic interval. QTL analysis also identified some well-separated QTL which could be readily transferred between the two pools. Based on the QTL analysis, we propose that improvement in yield could be achieved more readily by heterosis breeding rather than by pure line breeding.
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Affiliation(s)
- N Ramchiary
- Department of Genetics, University of Delhi South Campus, Benito Juarez Road, New Delhi 110021, India
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Padmaja KL, Arumugam N, Gupta V, Mukhopadhyay A, Sodhi YS, Pental D, Pradhan AK. Mapping and tagging of seed coat colour and the identification of microsatellite markers for marker-assisted manipulation of the trait in Brassica juncea. Theor Appl Genet 2005; 111:8-14. [PMID: 15902399 DOI: 10.1007/s00122-005-1933-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2004] [Accepted: 01/14/2005] [Indexed: 05/02/2023]
Abstract
Microsatellite marker technology in combination with three doubled haploid mapping populations of Brassica juncea were used to map and tag two independent loci controlling seed coat colour in B. juncea. One of the populations, derived from a cross between a brown-seeded Indian cultivar, Varuna, and a Canadian yellow-seeded line, Heera, segregated for two genes coding for seed coat colour; the other two populations segregated for one gene each. Microsatellite markers were obtained from related Brassica species. Three microsatellite markers (Ra2-A11, Na10-A08 and Ni4-F11) showing strong association with seed coat colour were identified through bulk segregant analysis. Subsequent mapping placed Ra2-A11 and Na10-A08 on linkage group (LG) 1 at an interval of 0.6 cM from each other and marker Ni4-F11 on LG 2 of the linkage map of B. juncea published previously (Pradhan et al., Theor Appl Genet 106:607-614, 2003). The two seed coat colour genes were placed with markers Ra2-A11 and Na10-A08 on LG 1 and Ni4-F11 on LG 2 based on marker genotyping data derived from the two mapping populations segregating for one gene each. One of the genes (BjSC1) co-segregated with marker Na10-A08 in LG 1 and the other gene (BjSC2) with Ni4-F11 in LG 2, without any recombination in the respective mapping populations of 130 and 103 segregating plants. The identified microsatellite markers were studied for their length polymorphism in a number of yellow-seeded eastern European and brown-seeded Indian germplasm of B. juncea and were found to be useful for the diversification of yellow seed coat colour from a variety of sources into Indian germplasm.
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Affiliation(s)
- K Lakshmi Padmaja
- Department of Genetics and Centre for Genetic Manipulation of Crop Plants, University of Delhi South Campus, Benito Juarez Road, New Delhi 110021, India
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