共查询到20条相似文献,搜索用时 468 毫秒
1.
We amplified resistance gene analogues (RGAs) from the genomic DNA of 10 rice lines having varying degree of resistance to Magnaporthe grisea by using degenerate primers and various RGAs were mapped in silico on different rice chromosomes. The amplified products were grouped into 3–8 restriction fragment length polymorphic classes by using Mbo1 and Alu1 restriction enzymes. Of 98 RGAs obtained in this study, 65 RGA clones showed more than 95% homology with various RGAs sequences present in the GenBank. Phylogenetic analysis of these RGAs formed 11 groups. Using sequence homology approach, RGAs isolated in this study were physically mapped on 23 loci on chromosomes 1, 2, 3, 4, 5, 6, 7, 8, 10, 11 and 12. Twenty RGAs were mapped near to the chromosomal regions containing known genes/QTLs for rice blast, bacterial leaf blight and sheath blight resistance. Thirty‐nine RGA sequences also contained open reading frame representing signature of potential disease resistance genes. 相似文献
2.
Barley disease resistance gene analogs of the NBS-LRR class: identification and mapping 总被引:11,自引:0,他引:11
Madsen LH Collins NC Rakwalska M Backes G Sandal N Krusell L Jensen J Waterman EH Jahoor A Ayliffe M Pryor AJ Langridge P Schulze-Lefert P Stougaard J 《Molecular genetics and genomics : MGG》2003,269(1):150-161
The majority of verified plant disease resistance genes isolated to date are of the NBS-LRR class, encoding proteins with a predicted nucleotide binding site (NBS) and a leucine-rich repeat (LRR) region. We took advantage of the sequence conservation in the NBS motif to clone, by PCR, gene fragments from barley representing putative disease resistance genes of this class. Over 30 different resistance gene analogs (RGAs) were isolated from the barley cultivar Regatta. These were grouped into 13 classes based on DNA sequence similarity. Actively transcribed genes were identified from all classes but one, and cDNA clones were isolated to derive the complete NBS-LRR protein sequences. Some of the NBS-LRR genes exhibited variation with respect to whether and where particular introns were spliced, as well as frequent premature polyadenylation. DNA sequences related to the majority of the barley RGAs were identified in the recently expanded public rice genomic sequence database, indicating that the rice sequence can be used to extract a large proportion of the RGAs from barley and other cereals. Using a combination of RFLP and PCR marker techniques, representatives of all barley RGA gene classes were mapped in the barley genome, to all chromosomes except 4H. A number of the RGA loci map in the vicinity of known disease resistance loci, and the association between RGA S-120 and the nematode resistance locus Ha2 on chromosome 2H was further tested by co-segregation analysis. Most of the RGA sequences reported here have not been described previously, and represent a useful resource as candidates or molecular markers for disease resistance genes in barley and other cereals. 相似文献
3.
Resistance gene analogues from rice: cloning, sequencing and mapping 总被引:18,自引:0,他引:18
R. Mago S. Nair M. Mohan 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,99(1-2):50-57
Degenerate oligonucleotide primers were designed on the basis of nucleotide-binding-site (NBS) motifs conserved between resistance
genes of Arabidopsis, flax and tobacco and subsequently used as PCR primers to amplify resistance gene analogues (RGA) in rice. Primers amplified
a major band of approximately 500 bp. Restriction analysis of the amplified product revealed that the band was made up of
several different fragments. Many of these fragments were cloned. Sixty different cloned fragments were analysed and assigned
to 14 categories based on Southern blot analysis. Fourteen clones, each representing one of the 14 categories of RGAs were
mapped onto the rice genetic map using a Nipponbare ( japonica)בKasalath’ (indica) mapping population consisting of 186 F2 lines. Of the 14 clones representing each class 12 could be mapped onto five different chromosomes of rice with a major cluster
of 8 RGAs on chromosome 11. Our results indicate that it is possible to use sequence homology from conserved motifs of known
resistance genes to amplify candidate resistance genes from diverse plant taxa.
Received: 23 September 1998 / Accepted: 28 November 1998 相似文献
4.
Characterisation and genetic mapping of resistance and defence gene analogs in cocoa (Theobroma cacao L.) 总被引:1,自引:0,他引:1
Lanaud Claire Risterucci Ange Marie Pieretti Isabelle N'Goran Jeanne A.K. Fargeas Dominique 《Molecular breeding : new strategies in plant improvement》2004,13(3):211-227
Disease resistance and defence gene analog (RGA/DGA) sequences were isolated in cocoa using a PCR approach with degenerate primers designed from conserved domains of plant resistance and defence genes: the NBS (nucleotide binding site) motif present in a number of resistance genes such as the tobacco N, sub-domains of plant serine/threonine kinases such as the Pto tomato gene, and conserved domains of two defence gene families: pathogenesis-related proteins (PR) of classes 2 and 5. Nucleotide identity between thirty six sequences isolated from cocoa and known resistance or defence genes varied from 58 to 80%. Amino acid sequences translated from corresponding coding sequences produced sequences without stop codons, except for one NBS –like sequence. Most of the RGAs could be mapped on the cocoa genome and three clusters of genes could be observed : NBS-like sequences clustered in two regions located on chromosomes 7 and 10, Pto-like sequences mapped in five genome regions of which one, located on chromosome 4, corresponded to a cluster of five different sequences. PR2-like sequences mapped in two regions located on chromosome 5 and 9 respectively. An enrichment of the genetic map with microsatellite markers allowed us to identify several co-localisations of RGAs, DGAs and QTL for resistance to Phytophthora detected in several progenies, particularly on chromosome 4 where a cluster of Pto-like sequences and 4 QTL for resistance to Phytophthora were observed. Many other serious diseases affect cocoa and the candidate genes, isolated in this study, could be of broader interest in cocoa disease management. 相似文献
5.
The resistance (R) proteins of the TIR- and non-TIR (or CC-) superfamilies possess a nucleotide binding site (NBS) domain.
Within an R gene, the NBS is the region of highest conservation, suggesting an essential role in triggering R protein activity. We compared
the NBS domain of functional R genes and resistance gene analogs (RGA) amplified from S. caripense genomic DNA via PCR using specific and degenerate primers with its counterpart from other plants. An overall high degree
of sequence conservation was apparent throughout the P-loop, kinase-2 and kinase-3a motifs of NBS fragments from all plants.
Within the non-TIR class of R genes a prominent sub-class similar to the potato R1 gene conferring resistance to late blight, was detected. All non-TIR-R1-like R gene fragments that were sequenced possessed an intact open reading frame, whereas 22% of all non-TIR-non-R1-like fragments
and 59% of all TIR-NBS RGA fragments had an interrupted reading frame or contained transposon-specific sequence. The non-TIR-R1-like
fragments had high similarity to Solanaceae R genes and low similarity to RGAs of other plant species including A. thaliana and the cereals. It is concluded that appearance of the non-TIR-R1-like NBS domain represents a relatively recent evolutionary
development.
Electronic supplementary material Supplementary material is available in the online version of this article at
and is accessible for authorized users. 相似文献
6.
Isolation and linkage analysis of expressed disease-resistance gene analogues of sugar beet (Beta vulgaris L.). 总被引:9,自引:0,他引:9
Sandra Hunger Gabriele Di Gaspero Slike M?hring Diana Bellin Ralf Sch?fer-Pregl Dietrich C Borchardt Charles-Eric Durel Martin Werber Bernd Weisshaar Francesco Salamini Katharina Schneider 《Génome》2003,46(1):70-82
7.
Candidate defense genes from rice,barley, and maize and their association with qualitative and quantitative resistance in rice 总被引:23,自引:0,他引:23
Ramalingam J Vera Cruz CM Kukreja K Chittoor JM Wu JL Lee SW Baraoidan M George ML Cohen MB Hulbert SH Leach JE Leung H 《Molecular plant-microbe interactions : MPMI》2003,16(1):14-24
8.
Cloning of resistance gene analogs located on the alien chromosome in an addition line of wheat-Thinopyrum intermedium 总被引:2,自引:0,他引:2
Jiang SM Hu J Yin WB Chen YH Wang RR Hu ZM 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2005,111(5):923-931
Homology-based gene/gene-analog cloning method has been extensively applied in isolation of RGAs (resistance gene analogs)
in various plant species. However, serious interference of sequences on homoeologous chromosomes in polyploidy species usually
occurred when cloning RGAs in a specific chromosome. In this research, the techniques of chromosome microdissection combined
with homology-based cloning were used to clone RGAs from a specific chromosome of Wheat-Thinopyrum alien addition line TAi-27,
which was derived from common wheat and Thinopyrum
intermedium with a pair of chromosomes from Th. intermedium. The alien chromosomes carry genes for resistance to BYDV. The alien chromosome in TAi-27 was isolated by a glass needle
and digested with proteinase K. The DNA of the alien chromosome was amplified by two rounds of Sau3A linker adaptor-mediated
PCR. RGAs were amplified by PCR with the degenerated primers designed based on conserved domains of published resistance genes
(R genes) by using the alien chromosome DNA, genomic DNA and cDNA of Th. intermedium, TAi-27 and 3B-2 (a parent of TAi-27) as templates. A total of seven RGAs were obtained and sequenced. Of which, a constitutively
expressed single-copy NBS-LRR type RGA ACR3 was amplified from the dissected alien chromosome of TAi-27, TcDR2 and TcDR3 were
from cDNA of Th. intermedium, AcDR3 was from cDNA of TAi-27, FcDR2 was from cDNA of 3B-2, AR2 was from genomic DNA of TAi-27 and TR2 was from genomic
DNA of Th. intermedium. Sequence homology analyses showed that the above RGAs were highly homologous with known resistance genes or resistance gene
analogs and belonged to NBS-LRR type of R genes. ACR3 was recovered by PCR from genomic DNA and cDNA of Th. intermedium and TAi-27, but not from 3B-2. Southern hybridization using the digested genomic DNA of Th. intermedium, TAi-27 and 3B-2 as the template and ACR3 as the probe showed that there is only one copy of ACR3 in the genome of Th. intermedium and TAi-27, but it is absent in 3B-2. The ACR3 could be used as a specific probe of the R gene on the alien chromosome of
TAi-27. Results of Northern hybridization suggested that ACR3 was constitutively expressed in Th. intermedium and TAi-27, but not 3B-2, and expressed higher in leaves than in roots. This research demonstrated a new way to clone RGAs
located on a specific chromosome. The information reported here should be useful to understand the resistance mechanism of,
and to clone resistant genes from, the alien chromosome in TAi-27. 相似文献
9.
Huang D Wu W Lu L 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2004,108(7):1371-1377
Amplification of resistance gene analogs (RGAs) is both a useful method for acquiring DNA markers closely linked to disease resistance (R) genes and a potential approach for the rapid cloning of R genes in plants. However, the screening of target sequences from among the numerous amplified RGAs can be very laborious. The amplification of RGAs from specific chromosomes could greatly reduce the number of RGAs to be screened and, consequently, speed up the identification of target RGAs. We have developed two methods for amplifying RGAs from single chromosomes. Method 1 uses products of Sau3A linker adaptor-mediated PCR (LAM-PCR) from a single chromosome as the templates for RGA amplification, while Method 2 directly uses a single chromosomal DNA molecule as the template. Using a pair of degenerate primers designed on the basis of the conserved nucleotide-binding-site motifs in many R genes, RGAs were successfully amplified from single chromosomes of pomelo using both these methods. Sequencing and cluster analysis of RGA clones obtained from single chromosomes revealed the number, type and organization of R-gene clusters on the chromosomes. We suggest that Method 1 is suitable for analyzing chromosomes that are unidentifiable under a microscope, while Method 2 is more appropriate when chromosomes can be clearly identified.Communicated by P. Langridge 相似文献
10.
Cloning and characterisation of a family of disease resistance gene analogs from wheat and barley 总被引:7,自引:0,他引:7
S. Seah K. Sivasithamparam A. Karakousis E. S. Lagudah 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,97(5-6):937-945
The most common class of plant disease resistance (R) genes cloned so far belong to the NBS-LRR group which contain nucleotide-binding
sites (NBS) and a leucine-rich repeat (LRR). Specific primer sequences derived from a previously isolated NBS-LRR sequence
at the Cre3 locus, which confers resistance to cereal cyst nematode (CCN) in wheat (Triticum aestivum L.) were used in isolating a family of resistance gene analogs (RGA) through a polymerase chain reaction (PCR) cloning approach.
The cloning, analysis and genetic mapping of a family of RGAs from wheat (cv ‘Chinese Spring’) and barley (Hordeum vulgare L. cvs ‘Chebec’ and ‘Harrington’) are presented. The wheat and barley RGAs contain other conserved motifs present in known
R genes from other plants and share between 55–99% amino acid sequence identity to the NBS-LRR sequence at the Cre3 locus. Phylogenetic analysis of the RGAs with other cloned R genes and RGAs from various plant species indicate that they
belong to a superfamily of NBS-containing genes. Two of the barley derived RGAs were mapped onto loci on chromosomes 2H (2),
5H (7) and 7H (1) using barley doubled haploid (DH) mapping populations. Some of these loci identified are associated with
regions carrying resistance to CCN and corn leaf aphid.
Received: 6 January 1998 / Accepted: 1 April 1998 相似文献
11.
Junrey C. Amas Philipp E. Bayer Wei Hong Tan Soodeh Tirnaz William J. W. Thomas David Edwards Jacqueline Batley 《Plant biotechnology journal》2023,21(10):2100-2112
Brassica rapa is grown worldwide as economically important vegetable and oilseed crop. However, its production is challenged by yield-limiting pathogens. The sustainable control of these pathogens mainly relies on the deployment of genetic resistance primarily driven by resistance gene analogues (RGAs). While several studies have identified RGAs in B. rapa, these were mainly based on a single genome reference and do not represent the full range of RGA diversity in B. rapa. In this study, we utilized the B. rapa pangenome, constructed from 71 lines encompassing 12 morphotypes, to describe a comprehensive repertoire of RGAs in B. rapa. We show that 309 RGAs were affected by presence-absence variation (PAV) and 223 RGAs were missing from the reference genome. The transmembrane leucine-rich repeat (TM-LRR) RGA class had more core gene types than variable genes, while the opposite was observed for nucleotide-binding site leucine-rich repeats (NLRs). Comparative analysis with the B. napus pangenome revealed significant RGA conservation (93%) between the two species. We identified 138 candidate RGAs located within known B. rapa disease resistance QTL, of which the majority were under negative selection. Using blackleg gene homologues, we demonstrated how these genes in B. napus were derived from B. rapa. This further clarifies the genetic relationship of these loci, which may be useful in narrowing-down candidate blackleg resistance genes. This study provides a novel genomic resource towards the identification of candidate genes for breeding disease resistance in B. rapa and its relatives. 相似文献
12.
Recently, a number of disease-resistance genes related to a diverse range of pathogens were isolated from a wide variety of plant species. The majority of plant disease-resistance genes encoded a nucleotide-binding site (NBS) domain. According to the comparisons of the NBS domain of cloned R -genes, it has shown highly conserved amino acid motifs in this structure, which made it possible to isolate resistance gene analogs (RGAs) by PCR using degenerate primers. We have designed three pairs of degenerate primers based on two conserved motifs in the NBS domain of resistance proteins encoded by R -genes to amplify genomic sequences from ryegrass ( Lolium sp.). Sixteen NBS-like RGAs were isolated from turf and forage type grasses. The sequence analysis of these RGAs revealed that there existed a high similarity (up to 85%) between RGA sequences among ryegrass species and other plants. The alignment of the predicted amino acid sequences of RGAs showed that ryegrass RGAs contained four conserved motifs (P-Loop, kinase-2, kinase-3a, GLPL) present in other known plant NBS-leucine rich repeat resistance genes. These ryegrass RGAs all belonged to non-toll and interleukin-1 receptor subclass. Phylogenetic analysis of ryegrass RGAs and other cloned R -genes indicated that gene mutation was the predominant source of gene variations, and the sequence polymorphism was due to purifying selection rather than diversifying selection. We further analyzed the source of gene variation in other monocots, rice, barley, wheat, and maize based on the data published before. Our analysis indicated that the source of RGA diversity in these monocots was the same as in ryegrass. Thus, monocots were probably the same as dicots in the source of RGA diversity. Ryegrass RGAs in the present paper represented a large group of resistance gene homologs in monocots. We discussed the origin and the evolution of R -genes in grass species. 相似文献
13.
Suren K. Samuelian Angela M. Baldo Jeremy A. Pattison Courtney A. Weber 《Tree Genetics & Genomes》2008,4(4):881-896
Plant R genes confer resistance to pathogens in a gene-for-gene mode. Seventy-five putative resistance gene analogs (RGAs) containing
conserved domains were cloned from Rubus idaeus L. cv. ‘Latham’ using degenerate primers based on RGAs identified in Rosaceae species. The sequences were compared to 195
RGA sequences identified from five Rosaceae family genera. Multiple sequence alignments showed high similarity at multiple
nucleotide-binding site (NBS) motifs with homology to Drosophila Toll and mammalian interleukin-1 receptor (TIR) and non-TIR
RNBSA-A motifs. The TIR sequences clustered separately from the non-TIR sequences with a bootstrap value of 76%. There were
11 clusters each of TIR and non-TIR type sequences of multiple genera with bootstrap values of more than 50%, including nine
with values of more than 75% and seven of more than 90%. Polymorphic sequence characterized amplified region and cleaved amplified
polymorphic sequence markers were developed for nine Rubus RGA sequences with eight placed on a red raspberry genetic linkage map. Phylogenetic analysis indicated four of the mapped
sequences share sequence similarity to groupTIR I, while three others were spread in non-TIR groups. Of the 75 Rubus RGA sequences analyzed, members were placed in five TIR groups and six non-TIR groups. These group classifications closely
matched those in 12 of 13 studies from which these sequences were derived. The analysis of related DNA sequences within plant
families elucidates the evolutionary relationship and process involved in pest resistance development in plants. This information
will aid in the understanding of R genes and their proliferation within plant genomes.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
14.
Vágújfalvi A Crosatti C Galiba G Dubcovsky J Cattivelli L 《Molecular & general genetics : MGG》2000,263(2):194-200
Although cold acclimation in cereals involves the expression of many cold-regulated genes, genetic studies have shown that
only very few chromosomal regions carry loci that play an important role in frost tolerance. To investigate the genetic relationship
between frost tolerance and the expression of cold-regulated genes, the expression and regulation of the wheat homolog of
the barley cold-regulated gene cor14b was studied at various temperatures in frost-sensitive and frost-tolerant wheat genotypes. At 18/15 °C (day/night temperatures)
frost-tolerant plants accumulated cor14b mRNAs and expressed COR14b proteins, whereas the sensitive plants did not. This result indicates that the threshold temperature
for induction of the wheat cor14b homolog is higher in frost-resistant plants, and allowed us to use this polymorphism in a mapping approach. Studies made
with chromosome substitution lines showed that the polymorphism for the threshold induction temperature of the wheat cor14b homolog is controlled by a locus(i) located on chromosome 5A of wheat, while the cor14b gene was mapped in Triticum monococcum on the long arm of chromosome 2Am. The analysis of single chromosome recombinant lines derived from a cross between Chinese Spring/Triticum spelta 5A and Chinese Spring/Cheyenne 5A identified two loci with additive effects that are involved in the genetic control of cor14b mRNA accumulation. The first locus was tightly linked to the marker psr911, while the second one was located between the marker Xpsr2021 and Frost resistance 1 (Fr1).
Received: 20 July 1999 / Accepted: 15 November 1999 相似文献
15.
Cloutier S McCallum BD Loutre C Banks TW Wicker T Feuillet C Keller B Jordan MC 《Plant molecular biology》2007,65(1-2):93-106
In hexaploid wheat, leaf rust resistance gene Lr1 is located at the distal end of the long arm of chromosome 5D. To clone this gene, an F1-derived doubled haploid population and a recombinant inbred line population from a cross between the susceptible cultivar
AC Karma and the resistant line 87E03-S2B1 were phenotyped for resistance to Puccinia triticina race 1-1 BBB that carries the avirulence gene Avr1. A high-resolution genetic map of the Lr1 locus was constructed using microsatellite, resistance gene analog (RGA), BAC end (BE), and low pass (LP) markers. A physical
map of the locus was constructed by screening a hexaploid wheat BAC library from cultivar Glenlea that is known to have Lr1. The locus comprised three RGAs from a gene family related to RFLP marker Xpsr567. Markers specific to each paralog were
developed. Lr1 segregated with RGA567-5 while recombinants were observed for the other two RGAs. Transformation of the susceptible cultivar
Fielder with RGA567-5 demonstrated that it corresponds to the Lr1 resistance gene. In addition, the candidate gene was also confirmed by virus-induced gene silencing. Twenty T
1 lines from resistant transgenic line T
0-938 segregated for resistance, partial resistance and susceptibility to Avr1 corresponding to a 1:2:1 ratio for a single hemizygous insertion. Transgene presence and expression correlated with the phenotype.
The resistance phenotype expressed by Lr1 seemed therefore to be dependant on the zygosity status. T
3-938 sister lines with and without the transgene were further tested with 16 virulent and avirulent rust isolates. Rust reactions
were all as expected for Lr1 thereby providing additional evidence toward the Lr1 identity of RGA567-5. Sequence analysis of Lr1 indicated that it is not related to the previously isolated Lr10 and Lr21 genes and unlike these genes, it is part of a large gene family.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
The Canadian Crown's right to retain a non-exclusive, royalty-free licence in and to any copyright is acknowledged. 相似文献
16.
Western white pine (Pinus monticola Dougl. ex. D. Don., WWP) shows genetic variation in disease resistance to white pine blister rust (Cronartium ribicola). Most plant disease resistance (R) genes encode proteins that belong to a superfamily with nucleotide-binding site domains (NBS) and C-terminal leucine-rich repeats (LRR). In this work a PCR strategy was used to clone R gene analogs (RGAs) from WWP using oligonucleotide primers based on the conserved sequence motifs in the NBS domain of angiosperm NBS-LRR genes. Sixty-seven NBS sequences were cloned from disease-resistant trees. BLAST searches in GenBank revealed that they shared significant identity to well-characterized R genes from angiosperms, including L and M genes from flax, the tobacco N gene and the soybean gene LM6. Sequence alignments revealed that the RGAs from WWP contained the conserved motifs identified in angiosperm NBS domains, especially those motifs specific for TIR-NBS-LRR proteins. Phylogenic analysis of plant R genes and RGAs indicated that all cloned WWP RGAs can be grouped into one major branch together with well-known R proteins carrying a TIR domain, suggesting they belong to the subfamily of TIR-NBS-LRR genes. In one phylogenic tree, WWP RGAs were further subdivided into fourteen clusters with an amino acid sequence identity threshold of 75%. cDNA cloning and RT-PCR analysis with gene-specific primers demonstrated that members of 10 of the 14 RGA classes were expressed in foliage tissues, suggesting that a large and diverse NBS-LRR gene family may be functional in conifers. These results provide evidence for the hypothesis that conifer RGAs share a common origin with R genes from angiosperms, and some of them may play important roles in defense mechanisms that confer disease resistance in western white pine. Ratios of non-synonymous to synonymous nucleotide substitutions (Ka/Ks) in the WWP NBS domains were greater than 1 or close to 1, indicating that diversifying selection and/or neutral selection operate on the NBS domains of the WWP RGA family.Communicated by R. Hagemann 相似文献
17.
Carmen Palomino M. D. Fernández-Romero J. Rubio A. Torres M. T. Moreno T. Millán 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,118(4):671-682
A composite linkage map was constructed based on two interspecific recombinant inbred line populations derived from crosses
between Cicer arietinum (ILC72 and ICCL81001) and Cicer reticulatum (Cr5-10 or Cr5-9). These mapping populations segregate for resistance to ascochyta blight (caused by Ascochyta rabiei), fusarium wilt (caused by Fusarium oxysporum f. sp. ciceris) and rust (caused by Uromyces ciceris-arietini). The presence of single nucleotide polymorphisms in ten resistance gene analogs (RGAs) previously isolated and characterized
was exploited. Six out of the ten RGAs were novel sequences. In addition, classes RGA05, RGA06, RGA07, RGA08, RGA09 and RGA10
were considerate putatively functional since they matched with several legume expressed sequences tags (ESTs) obtained under
infection conditions. Seven RGA PCR-based markers (5 CAPS and 2 dCAPS) were developed and successfully genotyped in the two
progenies. Six of them have been mapped in different linkage groups where major quantitative trait loci conferring resistance
to ascochyta blight and fusarium wilt have been reported. Genomic locations of RGAs were compared with those of known Cicer R-genes and previously mapped RGAs. Association was detected between RGA05 and genes controlling resistance to fusarium wilt
caused by races 0 and 5. 相似文献
18.
NBS-LRR sequence family is associated with leaf and stripe rust resistance on the end of homoeologous chromosome group 1S of wheat 总被引:7,自引:2,他引:5
W. Spielmeyer L. Huang H. Bariana A. Laroche B. S. Gill E. S. Lagudah 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,101(7):1139-1144
A detailed RFLP map was constructed of the distal end of the short arm of chromosome 1D of Aegilops tauschii and wheat. At least two unrelated resistance-gene analogs (RGAs) mapped close to known leaf rust resistance genes (Lr21 and Lr40) located distal to seed storage protein genes on chromosome 1DS. One of the two RGA clones, which was previously shown to
be part of a candidate gene for stripe rust resistance (Yr10) located within the homoeologous region on 1BS, identified at least three gene family members on chromosome 1DS of Ae. tauschii. One of the gene members co-segregated with the leaf rust resistance genes, Lr21 and Lr40, in Ae. tauschii and wheat segregating families. Hence, a RGA clone derived from a candidate gene for stripe rust resistance located on chromosome
1BS detected candidate genes for leaf rust resistance located in the corresponding region on 1DS of wheat.
Received: 10 January 2000 / Accepted: 25 March 2000 相似文献
19.
Muehlbauer GJ Bhau BS Syed NH Heinen S Cho S Marshall D Pateyron S Buisine N Chalhoub B Flavell AJ 《Molecular genetics and genomics : MGG》2006,275(6):553-563
Transposable elements are ubiquitous genomic parasites with an ancient history of coexistence with their hosts. A few cases have emerged recently where these genetic elements have been recruited for normal function in the host organism. We have identified an expressed hobo/Ac/Tam (hAT) family transposase-like gene in cereal grasses which appears to represent such a case. This gene, which we have called gary, is found in one or two copies in barley, two diverged copies in rice and two very similar copies in hexaploid wheat. No gary homologues are found in Arabidopsis. In all three cereal species, an apparently complete 2.5 kb transposase-like open reading frame is present and nucleotide substitution data show evidence for positive selection, yet the predicted gary protein is probably not an active transposase, as judged by the absence of key amino acids required for transposase function. Gary is expressed in wheat and barley spikes and gary cDNA sequences are also found in rice, oat, rye, maize, sorghum and sugarcane. The short inverted terminal repeats, flanked by an eight-nucleotide host sequence duplication, which are characteristic of a hAT transposon are absent. Genetic mapping in barley shows that gary is located on the distal end of the long arm of chromosome 2H. Wheat homologues of gary map to the same approximate location on the wheat group 2 chromosomes by physical bin-mapping and the more closely related of the two rice garys maps to the syntenic location near the bottom of rice chromosome 4. These data suggest that gary has resided in a single genomic location for at least 60 Myr and has lost the ability to transpose, yet expresses a transposase-related protein that is being conserved under host selection. We propose that the gary transposase-like gene has been recruited by the cereal grasses for an unknown function.Electronic Supplementary Material Supplementary material is available for this article at and is accessible for authorized users. 相似文献
20.
McFadden HG Lehmensiek A Lagudah ES 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2006,113(6):987-1002
Using two divergent nucleotide binding site (NBS) regions from wheat sequences of the NBS-LRR (leucine rich repeat) class, we retrieved 211 wheat and barley NBS-containing resistance gene analogue (RGA) expressed sequence tags (ESTs). These ESTs were grouped into 129 gene sequence groups that contained ESTs that were at least 70% identical at the DNA level over at least 200 bp. Probes were obtained for 89 of these RGA families and chromosome locations were determined for 72 of these probes using nullitetrasomic Chinese Spring wheat lines. RFLP analysis of 49 of these RGA probes revealed 65 mappable polymorphic bands in the doubled haploid Cranbrook × Halberd wheat population (C × H). These bands mapped to 49 loci in C × H. RGA loci were detected on all 21 chromosomes using the nullitetrasomic lines and on 18 chromosomes (linkage groups) in the C × H map. This identified a set of potential markers that could be developed further for use in mapping and ultimately cloning NBS-LRR-type disease resistance genes in wheat.Electronic Supplementary Material Supplementary material is available to authorised users in the online version of this article at . 相似文献