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1.
RFLP- and physical mapping of resistance gene homologues in rice (O. sativa) and Barley (H. vulgare)
D. Leister J. Kurth D. A. Laurie M. Yano T. Sasaki A. Graner P. Schulze-Lefert 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,98(3-4):509-520
The deduced peptide sequences of 25 gene fragments of NBS-LRR resistance (R) gene homologues from rice and barley and of characterized R genes were compared, revealing a string of six conserved motifs. Mapping of the R-gene candidates in rice showed linkage to genes conferring race-specific resistance to rice blast (Pi-k, Pi-f and Pi-1) and bacterial blight disease (Xa-1, Xa-3 and Xa-4), in barley to powdery mildew (Mla) and the rust fungus (Rpg1). In rice four mixed clusters were detected, each harboring at least two highly dissimilar NBS-LRR genes. A YAC-contig was
established for one of these mixed clusters. YAC fragmentation experiments revealed the presence of at least five NBS-LRR
genes within 200 kb in head-to-tail orientation.
Received: 24 July 1998 / Accepted: 14 August 1998 相似文献
2.
Homoeologous set of NBS-LRR genes located at leaf and stripe rust resistance loci on short arms of chromosome 1 of wheat 总被引:2,自引:0,他引:2
Homoeologous group 1 chromosomes of wheat contain important genes that confer resistance to leaf, stem and stripe rusts,
powdery mildew and Russian wheat aphid. A disease resistance gene analog encoding nucleotide binding site-leucine rich repeat
(NBS-LRR), designated RgaYr10, was previously identified at the stripe rust resistant locus, Yr10, located on chromosome 1BS distal to the storage protein, Gli-B1 locus. RgaYr10 identified gene members in the homoeologous region of chromosome 1DS cosegregating with the leaf rust resistance
gene, Lr21, which originally was transferred from a diploid D genome progenitor. Four RgaYr10 gene members were isolated from chromosome
1DS and compared to two gene members previously isolated from the chromosome 1BS homeologue. NBS-LRR genes tightly linked
to stripe rust resistance gene Yr10 on chromosome 1BS were closely related in sequence and structure to NBS-LRR genes tightly linked to leaf rust resistance
gene Lr21 located within the homoeologous region on chromosome 1DS. The level of sequence homology was similar between NBS-LRR genes
that were isolated from different genomes as compared to genes from the same genome.
Electronic Publication 相似文献
3.
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
4.
M. B. Kirkham 《Plant and Soil》1988,105(1):19-24
Genotypes of sorghum [Sorghum bicolor (L.) Moench] vary in drought resistance. Yet it is not known if their hydraulic resistances vary. The objective of this study
was to determine if the hydraulic resistance of a drought-resistant sorghum was the same as that of a drought-sensitive sorghum.
Leaf water and osmotic potentials were measured daily, during a 14-d period, in leaves of a drought-resistant (‘KS9’) and
a drought-sensitive (‘IA25’) sorghum, which had the roots in pots with a commercial potting soil that was either well watered
or allowed to dry. Soil water potential, adaxial stomatal resistance, and transpiration rate were determined daily. Hydraulic
resistance of the plants was calculated from the slope of the line relating soil water potential minus leaf water potential
versus transpiration rate. When the soil was not watered, the drought-sensitive sorghum had a water potential that averaged
−0.50 MPa lower and an osmotic potential that averaged −0.57 MPa lower, but a similar adaxial stomatal resistance (1.19 s
mm−1), compared with the drought-resistant sorghum. Seven days after the beginning of the experiment, the water potential of the
soil with the drought-sensitive sorghum was −0.25 MPa lower than that of the soil with the drought-resistant sorghum. With
the water-limited conditions, the drought-sensitive sorghum depleted the soil-water reserve more quickly and died 2 d before
the drought-resistant sorghum. Under well watered conditions, the two sorghums had similar water potentials (−1.64 MPa), osmotic
potentials (−2.83 MPa), and adaxial stomatal resistances (0.78 s mm−1). The calculated hydraulic resistance of the two sorghums did not differ and averaged 3.4 × 107 MPa s m−1. The results suggested that the variation in susceptibility to drought between the two genotypes was due to differences in
rate of soil-water extraction.
Contribution No. 86-249-J from the Kansas Agricultural Experiment Station. The paper is dedicated to the memory of Dr Dan
M Rodgers. 相似文献
5.
6.
Paolo Galli Giovanni Antonio Lodovico Broggini Markus Kellerhals Cesare Gessler Andrea Patocchi 《Molecular breeding : new strategies in plant improvement》2010,26(4):561-572
The Rvi15 (Vr2) apple scab resistance locus found in the GMAL 2473 accession has been previously mapped to the top of the Linkage Group
2 (LG2) by analyzing 89 progeny plants of a cross between ‘Idared’ and GMAL 2473. A new population of 989 progeny plants,
derived from a cross between ‘Golden Delicious’ and GMAL 2473, has been analyzed with the two SSR markers CH02c02a and CH02f06,
previously found to be associated with Rvi15 (Vr2), and with two published markers derived from NBS sequences (ARGH17 and ARGH37) estimated to map close to the Rvi15 (Vr2) locus. ARGH17 and ARGH37, were found to be the closest markers to the resistance locus, bracketing it within an interval
of 1.5 cM. The SSRs mapped one on each side of Rvi15 (Vr2). CH02f06 mapped at 2.9 cM from ARGH37 while CH02a02a mapped at 1.7 from ARGH17. The position of Rvi15 (Vr2) respect to CH02a02a indicates that Rvi15 (Vr2) and Rvi4 (Vh4), a second apple scab gene mapped on the top of LG2, are two different resistance genes. In order to develop even more tightly
linked markers to Rvi15 (Vr2), ARGH17 was used as the starting point for chromosome walking through the Rvi15 (Vr2) homolog region of the cv. ‘Florina’. A single ‘Florina’ BAC clone, 36I17, was sufficient to span the homologous locus in
the new population’s recombinant progeny. Sequencing of the 36I17 BAC clone allowed identifying seven putative ORFs, including
two showing a TIR-NBS-LRR structure. Ten additional markers could be developed mapping within a 1.8 cM interval around the
Rvi15 (Vr2) resistance gene. ARGH17 and GmTNL1 markers, the latter also derived from NBS-LRR resistance gene homolog sequence, are the
closest markers to Rvi15 (Vr2) bracketing it within a 0.5 cM interval. The availability of 12 markers within the Rvi15 (Vr2) region, all within a small physical distance (kbp) in ‘Florina’, suggests that cloning of the Rvi15 (Vr2) apple scab resistance gene from GMAL 2473 will be possible. 相似文献
7.
A. C. J. Frijters Z. Zhang M. van Damme G.-L. Wang P. C. Ronald R. W. Michelmore 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,94(3-4):390-399
Existing bacterial artificial chromosome (BAC) vectors were modified to have unique EcoRI cloning sites. This provided an additional site for generating representative libraries from genomic DNA digested with
a variety of enzymes. A BAC library of lettuce was constructed following the partial digestion of genomic DNA with HindIII or EcoRI. Several experimental parameters were investigated and optimized. The BAC library of over 50,000 clones, representing one
to two genome equivalents, was constructed from six ligations; average insert sizes for each ligation varied between 92.5
and 142 kb with a combined average insert size of 111 kb. The library was screened with markers linked to disease resistance
genes; this identified 134 BAC clones from four regions containing resistance genes. Hybridization with low-copy genomic sequences
linked to resistance genes detected fewer clones than expected from previous estimates of genome size. The lack of hybridization
to chloroplast and mitochondrial sequences demonstrated that the library was predominantly composed of nuclear DNA. The unique
EcoRI site in the BAC vector should allow the integration of BAC cloning with other technologies that utilize EcoRI digestion, such as AFLPTM markers and RecA-assisted restriction endonuclease (RARE) cleavage, to clone specific large EcoRI fragments from genomic DNA.
Received: 5 August 1996 / Accepted: 23 August 1996 相似文献
8.
Characterization and expression profiling of a novel cereal cyst nematode resistance gene analog in wheat 总被引:1,自引:0,他引:1
X. G. Zhai T. Zhao Y. H. Liu H. Long G. B. Deng Z. F. Pan M. Q. Yu 《Molecular Biology》2008,42(6):960-965
Based on the conserved regions of known resistance genes, an NBS-LRR-type CCN resistance gene analog was isolated from the
CCN resistant E-10 near isogenic lines (NILs) of wheat, designated as CreZ (GenBank accession number: EU327996). It contained a complete ORF that was 2775 bp in length and encoded 924 amino acids.
Sequence comparison indicated that it shared 92% nucleotide and 87% amino acid identity with those of the known CCN-resistance
gene Cre3 and had similar characteristic conserved motifs to those in other established NBS-LRR disease resistance genes. The expression
profiling of CreZ indicated that it was specifically expressed in the roots of resistant plants and real-time PCR analysis demonstrated that
expression levels drastically increased when the plants were inoculated with cereal cyst nematodes. It could be inferred,
then, that CreZ belongs to the NBS-LRR resistance gene family and is a candidate gene for potential resistance to the cereal cyst nematode.
Published in Russian in Molekulyarnaya Biologiya, 2008, Vol. 42, No. 6, pp. 1070–1077.
The text was submitted by the authors in English. 相似文献
9.
S. Nakamura S. Asakawa N. Ohmido K. Fukui N. Shimizu S. Kawasaki 《Molecular & general genetics : MGG》1997,254(6):611-620
We constructed a rice Bacterial Artificial Chromosome (BAC) library from green leaf protoplasts of the cultivar Shimokita
harboring the rice blast resistance gene Pi-ta. The average insert size of 155 kb and the library size of seven genome equivalents make it one of the most comprehensive
BAC libraries available, and larger than many plant YAC libraries. The library clones were plated on seven high density membranes
of microplate size, enabling efficient colony identification in colony hybridization experiments. Seven percent of clones
carried chloroplast DNA. By probing with markers close to the blast resistance genes Pi-ta
2
(closely linked to Pi-ta) and Pi-b, respectively located in the centromeric region of chromosome 12 and near the telomeric end of chromosome 2, on average 2.2 ± 1.3
and 8.0 ± 2.6 BAC clones/marker were isolated. Differences in chromosomal structures may contribute to this wide variation
in yield. A contig of about 800 kb, consisting of 19 clones, was constructed in the Pi-ta
2
region. This region had a high frequency of repetitive sequences. To circumvent this difficulty, we devised a “two-step walking”
method. The contig spanned a 300 kb region between markers located at 0 cM and 0.3 cM from Pi-ta
2
. The ratio of physical to genetic distances (> 1,000 kb/cM) was more than three times larger than the average of rice (300
kb/cM). The low recombination rate and high frequency of repetitive sequences may also be related to the near centromeric
character of this region. Fluorescent in situ hybridization (FISH) with a BAC clone from the Pi-b region yielded very clear signals on the long arm of chromosome 2, while a clone from the Pi-ta
2
region showed various cross-hybridizing signals near the centromeric regions of all chromosomes.
Received: 14 August 1996 / Accepted: 2 December 1996 相似文献
10.
Frans J. M. Maathuis 《Plant and Soil》2007,299(1-2):1-15
Toxic aluminum (Al) ion is a major constraint to plant growth in acid soils. Aluminum tolerance in wheat (Triticum aestivum L.) is strongly related to the Al-triggered efflux of malate from root apices. A role of the secreted malate has been postulated
to be in chelating Al and thus excluding it from root apices (malate hypothesis), but the actual process has yet to be fully
elucidated. We measured Al content and root growth during and after Al exposure using seedlings of near-isogenic lines [ET8
(Al tolerant) and ES8 (Al sensitive)] differing in the capacity to induce Al-triggered malate efflux. Aluminum doses that
caused 50% root growth inhibition during 24-h exposure to Al in calcium (Ca) solution (0.5 mM CaCl2, pH 4.5) were 50 μM in ET8 and 5 μM in ES8. Under such conditions, the amount of Al accumulated in root apices was approximately
2-fold higher in ET8 than ES8. Al-treated seedlings were then transferred to the Al-free Ca solution for 24 h. Compared to
control roots (no Al pretreatment), root regrowth of Al-treated roots was about 100% in ET8 and about 25% in ES8. The impaired
regrowth in ES8 was observed even after 24-h exposure to 2.5 μM Al which had caused only 20% root growth inhibition. The addition
of malate (100 μM) during exposure to 50 μM Al in ES8 enhanced root growth 1.6 times and regrowth in Al-free solution 7 times,
resulting in similar root growth and regrowth as in ET8. Short-term Al treatments of ES8 for up to 5 h indicated that the
Al-caused inhibition of root regrowth started after 1-h exposure to Al. The stimulating effect of malate on root regrowth
was observed when malate was present during Al exposure, but not when roots previously exposed to Al were rinsed with malate,
although Al accumulation in root apices was similar under these malate treatments. We conclude that the malate secreted from
root apices under Al exposure is essential for the apices to commence regrowth in Al-free medium, the trait that is not related
to the exclusion of Al from the apices. 相似文献
11.
Streptomyces lividans 1326 carries inducible mercury resistance genes on the chromosome, which are arranged in two divergently transcribed operons.
Expression of the genes is negatively regulated by the repressor MerR, which binds in the intercistronic region between the
two operons. The merR gene was expressed in E. coli using a T7 RNA polymerase/promoter expression system, and MerR was purified to around 95% homogeneity by ammonium sulfate
precipitation, gel filtration and affinity chromatography. Gel filtration showed that the native MerR is a dimer with a molecular
mass of 31 kDa. Two DNA binding sites were identified in the intercistronic mer promoter region by footprinting experiments. No evidence for cooperativity in the binding of MerR to the adjacent operator
sequences was observed in gel mobility shift assays. The dissociation constants (KD) for binding of MerR were: binding site I, 8.5 × 10−9 M; binding site II, 1.2 × 10−8 M; and for the complete promoter/operator region 1 × 10−8 M. The half-life of the MerR-DNA complex was 19.4 min and 18.8 min for binding site I and binding site II, respectively.
The KD value for binding of mercury(II)chloride to MerR, again determined by mobility shift assay, was 1.1 × 10−7 M.
Received: 18 August 1998 / Accepted: 5 May 1999 相似文献
12.
Paul N. Adler Elisabeth C. Martin Jeannette Charlton Katherine Jones 《Genesis (New York, N.Y. : 2000)》1991,12(5):349-361
The Posterior Sex Combs (Psc) gene of Drosophila is a member of the Polycomb (Pc) group of transregulatory genes. Previous analyses of the function of this gene in Drosophila em-bryogenesis have been hampered by the lack of a null mutation. We recently isolated a mutation that deletes the 5′ end of the Psc gene. This allele appears to be a null mutation, and we have used it to determine the Psc zygotic null phenotype and to look at the interactions of a null allele of Psc with five other Pc group mutations. We find evidence for transformations along both the anterior-posterior and dorsal-ventral axes in embryos of a variety of genotypes that include a null mutation in Psc. The phenotypes of embryos that are doubly mutant for a null allele of Psc and a mutation in a second Pc group gene show dramatic synergistic effects, but in their specifics they are dependent on the identify of the second Pc group gene. This is different from the relatively uniform phenotypes seen among double mutants that contained the allele Psc1, which has both gain and loss of function properties. The differences in the phenotypes of the doubly mutant embryos allow us to eliminate one class of molecular models to explain the dramatic synergism seen with mutations in this group of genes. 相似文献
13.
Natural Occurrence of Mycotoxins in Staple Cereals from Ethiopia 总被引:1,自引:0,他引:1
The occurrence of mycotoxins in barley, sorghum, teff (Eragrostis tef) and wheat from Ethiopia has been studied. Samples were analyzed for aflatoxin B1 (AFB1), ochratoxin A (OTA), deoxynivalenol (DON), nivalenol (NIV) and zearalenone (ZEN) using high performance liquid chromatography
(HPLC) and for fumonisins (FUM) using enzyme linked immunosorbent assay (ELISA). AFB1 and OTA were detected in samples of
all the four crops. AFB1 was detected in 8.8% of the 352 samples analyzed at concentrations ranging from trace to 26 μg kg−1. OTA occurred in 24.3% of 321 samples at a mean concentration of 54.1 μg kg−1 and a maximum of 2106 μg kg−1. DON occurred in barley, sorghum and wheat at 40–2340 μg kg−1 with an overall incidence of 48.8% among the 84 mainly ‘suspect’ samples analyzed; NIV was co-analyzed with DON and was detected
at 40 μg kg−1 in a wheat sample and at 50, 380, and 490 μg kg−1 in three sorghum samples. FUM and ZEN occurred only in sorghum samples with low frequencies at concentrations reaching 2117
and 32 μg kg−1, respectively. The analytical results indicate higher mycotoxin contamination in sorghum, which could be related to the widespread
storage of sorghum grain in underground pits leading to elevated seed moisture contents. This is the first report on the occurrence
of OTA in teff. 相似文献
14.
Kami J Poncet V Geffroy V Gepts P 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2006,112(6):987-998
The APA family of seed proteins consists of three subfamilies, in evolutionary order of hypothesized appearance: phytohaemagglutinins
(PHA), α-amylase inhibitors (αAI), and arcelins (ARL). The APA family plays a defensive role against mammalian and insect
seed predation in common bean (Phaseolus vulgaris L.). The main locus (APA) for this gene family is situated on linkage group B4. In order to elucidate the pattern of duplication and diversification
at this locus, we developed a BAC library in each of four different Phaseolus genotypes that represent presumptive steps in the evolutionary diversification of the APA family. Specifically, BAC libraries
were established in one P. lunatus (cv. ‘Henderson: PHA+ αAI− ARL−) and three P. vulgaris accessions (presumed ancestral wild G21245 from northern Peru: PHA+ αAI + ARL−; Mesoamerican wild G02771: PHA+ αAI + ARL+; and Mesoamerican breeding line BAT93: PHA+ αAI + ARL−). The libraries were constructed after HindIII digestion of high molecular weight DNA, obtained with a novel nuclei isolation procedure. The frequency of empty or cpDNA-sequence-containing
clones in all libraries is low (generally <1%). The Henderson, G21245, and G02771 libraries have a 10× genome coverage, whereas
the BAT93 library has a 20× coverage to allow further, more detailed genomic analysis of the bean genome. The complete sequence
of a 155 kbp-insert clone of the G02771 library revealed six sequences belonging to the APA gene family, including members
of the three subfamilies, as hypothesized. The different subfamilies were interspersed with retrotransposon sequences. In
addition, other sequences were identified with similarity to chloroplast DNA, a dehydrin gene, and the Arabidopsis flowering
D locus. Linkage between the dehydrin gene and the D1711 RFLP marker identifies a potential syntenic region between parts of common bean linkage group B4 and cowpea linkage group
2 相似文献
15.
Construction of a 550 kb BAC contig spanning the genomic region containing the apple scab resistance gene Vf 总被引:2,自引:0,他引:2
Patocchi A Vinatzer BA Gianfranceschi L Tartarini S Zhang HB Sansavini S Gessler C 《Molecular & general genetics : MGG》1999,262(4-5):884-891
A positional cloning project was started in apple with the aim of isolating the Vf resistance gene of Malus floribunda 821. Vf confers resistance against apple scab, the most important disease in apple orchards. A chromosome walk starting from two
molecular markers (M18-CAPS and AM19-SCAR) flanking Vf was performed, using a bacterial artificial chromosome (BAC) library containing inserts of the cultivar Florina, which is
heterozygous for Vf. Thirteen BAC clones spanning the region between the two markers were identified in nine chromosome walking steps. The size
of the resulting contig is approximately 550 kb. In order to map the Vf region in more detail, we analyzed over 2000 plants from different populations segregating for Vf with markers produced from BAC end sequences. In this way, we were able to restrict the possible location of the Vf gene to a minimum of five clones spanning an interval of approximately 350 kb.
Received: 4 July 1999 / Accepted: 16 September 1999 相似文献
16.
Jeung JU Kim BR Cho YC Han SS Moon HP Lee YT Jena KK 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2007,115(8):1163-1177
Rice blast disease caused by Magnaporthe grisea is a continuous threat to stable rice production worldwide. In a modernized agricultural system, the development of varieties
with broad-spectrum and durable resistance to blast disease is essential for increased rice production and sustainability.
In this study, a new gene is identified in the introgression line IR65482-4-136-2-2 that has inherited the resistance gene
from an EE genome wild Oryza species, O. australiensis (Acc. 100882). Genetic and molecular analysis localized a major resistance gene, Pi40(t), on the short arm of chromosome 6, where four blast resistance genes (Piz, Piz-5, Piz-t, and Pi9) were also identified, flanked by the markers S2539 and RM3330. Through e-Landing, 14 BAC/PAC clones within the 1.81-Mb equivalent virtual contig were identified on Rice Pseudomolecule3. Highly stringent
primer sets designed for 6 NBS-LRR motifs located within PAC clone P0649C11 facilitated high-resolution mapping of the new
resistance gene, Pi40(t). Following association analysis and detailed haplotyping approaches, a DNA marker, 9871.T7E2b, was identified to be linked
to the Pi40(t) gene at the 70 Kb chromosomal region, and differentiated the Pi40(t) gene from the LTH monogenic differential lines possessing genes Piz, Piz-5, Piz-t, and Pi-9. Pi40(t) was validated using the most virulent isolates of Korea as well as the Philippines, suggesting a broad spectrum for the resistance
gene. Marker-assisted selection (MAS) and pathotyping of BC progenies having two japonica cultivar genetic backgrounds further
supported the potential of the resistance gene in rice breeding. Our study based on new gene identification strategies provides
insight into novel genetic resources for blast resistance as well as future studies on cloning and functional analysis of
a blast resistance gene useful for rice improvement. 相似文献
17.
Bachlava E Radwan OE Abratti G Tang S Gao W Heesacker AF Bazzalo ME Zambelli A Leon AJ Knapp SJ 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2011,122(6):1211-1221
Nucleotide binding site-leucine rich repeat (NBS-LRR) proteins are encoded by a ubiquitous gene family in sunflower and frequently
harbor disease resistance genes. We investigated NBS-LRR-encoding resistance gene candidates (RGCs) flanking the downy mildew
resistance genes Pl
8
and Pl
14
and the rust resistance gene R
Adv
, which map on the NBS-LRR clusters of linkage groups 1 and 13 in sunflower genome. We shotgun sequenced bacterial artificial
chromosome (BAC) clones proximal to Pl
8
, Pl
14
, and R
Adv
and identified seven novel non-Toll/interleukin-1 receptor (TIR)-like NBS-LRR RGCs, which clustered with previously identified
RGCs of linkage group 13 but were phylogenetically distant from the TIR- and non-TIR-NBS-LRR-encoding superfamilies of sunflower.
Six of the seven predicted RGCs have intact open reading frames and reside in genomic segments with abundant transposable
elements. The genomic localization and sequence similarity of the novel non-TIR-like predicted RGCs suggests that they originated
from tandem duplications. RGCs in the proximity of Pl
8
and R
Adv
were likely introgressed from silverleaf sunflower genome, where the RGC cluster of linkage group 13 is duplicated in two
independent chromosomes that have different architecture and level of recombination from the respective common sunflower chromosomes. 相似文献
18.
An efficient protocol for the Agrobacterium tumefaciens-mediated transformation of calla lily (Zantedeschia elliottiana (W. Wats.) Engl. cultivar ‘Florex Gold’) is described. Shoot basal discs were co-cultivated with A. tumefaciens C58C1 carrying a plasmid containing neomycin phosphotransferase (nptII) and plant ferredoxin-like protein (pflp) genes. After Agrobacterium co-cultivation, the shoot basal discs were exposed to 100 mg l−1 kanamycin for selection. Twenty-eight out of 260 discs (10.8%) were found to have survived and produced shoot clusters. Twenty-six
of these were confirmed to contain the pflp transgene by PCR, ending up in 10% transformation efficiency. The disease resistance investigation revealed that 18 transgenic
plants exhibited resistance to soft rot disease caused by Erwinia carotovora subsp. carotovora. The presence of pflp gene was demonstrated by PCR, and its accumulation and activity was confirmed by Western blot and disease resistance assay.
This was the first report to show the successful transformation and resistance to a bacterial pathogen in Zantedeschia. The protocol is useful for the quality improvement of calla lily through genetic transformation. 相似文献
19.
N. Selvaraj S. Kasthurirengan A. Vasudevan M. Manickavasagam C. W. Choi A. Ganapathi 《In vitro cellular & developmental biology. Plant》2010,46(4):329-337
Efficient Agrobacterium tumefaciens-mediated transformation and a higher recovery of transformed plants of cucumber cv. Poinsett76 were achieved via direct organogenesis
from cotyledon explants. Stable transformants were obtained by inoculating explants with A. tumefaciens strains EHA105 or LBA4404, both harboring the binary vector pME508, which contains the neomycin phosphotransferase II (nptII) and phosphinothricin resistance genes (bar) conferring resistance to kanamycin and PPT, respectively, as selectable markers and the sgfp-tyg gene for the green fluorescent protein (GFP) as a visual marker driven by the constitutive CaMV35S promoter in the presence
of acetosyringone (50 μM). Transformed shoots were obtained on MS Murashige and Skoog (Plant Physiol. 15: 473–497, 1962) medium supplemented with 1 mg L−1 benzyladenine (BA), 20 mg L−1
l-glutamine and 2 mg L−1 phosphinothricin (PPT) or 100 mg L−1 kanamycin. The regenerated shoots were examined in vivo using a hand-held long wave UV lamp for GFP expression. The GFP screening helped identify escapes and chimeric shoots at
regular intervals to increase the growth of transformed shoots on cotyledon explants. Elongation and rooting of putative transformants
were achieved on PPT (2 mg L−1) containing MS media with 0.5 mg L−1 gibberellic acid (GA3) and 0.6 mg L−1 indole butyric acid (IBA), respectively. PCR and Southern analyses confirmed the integration of the sgfp gene into the genome of T0 and the progenies. T1 segregation of transgenic progeny exhibited Mendelian inheritance of the transgene. The use of EHA105 resulted in 21% transformation
efficiency compared to 8.5% when LBA4404 was used. This higher rate was greatly facilitated by PPT selection coupled with
effective screening of transformants for GFP expression, thus making the protocol highly useful for the recovery of a higher
number of transgenic cucumber plants. 相似文献
20.
The maize rp1 rust resistance gene identifies homologues in barley that have been subjected to diversifying selection 总被引:1,自引:0,他引:1
M.A. Ayliffe N.C. Collins J.G Ellis A. Pryor 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,100(7):1144-1154
A number of agronomically important grasses (sorghum, wheat, panicum, sugar cane, oats, rice and barley) are shown to contain
sequences homologous to rp1, a maize gene that confers race-specific resistance to the rust fungus Puccinia sorghi. Mapping of rp1-related sequences in barley identified three unlinked loci on chromosomes 1HL, 3HL and 7HS. The locus located on chromosome
7HS comprises a small gene family of at least four members, two of which were isolated and are predicted to encode nucleotide
binding site-leucine-rich repeat (NBS-LRR) proteins that are respectively 58% and 60% identical to the maize rp1 protein. Evidence of positive selection for sequence diversification acting upon these two barley genes was observed; however,
diversifying selection was restricted to the carboxy terminal half of the LRR domain. One of these rp1 homologous genes cosegregated with the barley Rpg1 stem rust resistance gene amongst 148 members of the Steptoe × Morex double haploid mapping family. Three other unrelated
resistance gene-like sequences, potentially encoding NBS-LRR proteins, are also shown to be linked to the Rpg1 locus but not cosegregating with the gene.
Received: 2 August 1999 / Accepted: 28 September 1999 相似文献