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1.
Lolium temulentum L. (Darnel ryegrass) has been proposed to be used as a model species for functional genomics studies in forage and turf grasses,
because it is a self-fertile, diploid species with a short life cycle and is closely related to other grasses. Embryogenic
calluses were induced from mature embryos of a double haploid line developed through anther culture. The calluses were broken
up into small pieces and used for Agrobacterium tumefaciens-mediated transformation. A. tumefaciens strain EHA105 harboring pCAMBIA1301 and pCAMBIA1305.2 vectors were used to infect embryogenic callus pieces. Hygromycin was
used as a selection agent in stable transformation experiments. Hygromycin resistant calluses were obtained after 4–6 weeks
of selection and transgenic plants were produced in 10–13 weeks after Agrobacterium-mediated transformation. Fertile plants were readily obtained after transferring the transgenics to the greenhouse. Transgenic
nature of the regenerated plants was demonstrated by Polymerase chain reaction (PCR), Southern hybridization analysis, and
GUS staining. Progeny analysis showed Mendelian inheritance of the transgenes. The transformation system provides a valuable
tool for functionality tests of candidate genes in forage and turf grasses. 相似文献
2.
A. Nadolska-Orczyk A. Przetakiewicz K. Kopera A. Binka W. Orczyk 《Journal of Plant Growth Regulation》2005,24(1):2-10
Transgenic plants of triticale cv. Wanad were obtained after transformation using three combinations of strain/vectors. Two
of them were hypervirulent Agrobacterium tumefaciens strains (AGL1 and EHA101) with vectors containing bar under maize ubiquitin 1 promoter (pDM805), and both hpt under p35S and nptII under pnos (pGAH). The third one was a regular LBA4404 strain containing super-binary plasmid pTOK233 with selection genes
the same as in pGAH. The efficiency of transformation was from 0 to 16% and it was dependent on the selection factor, auxin
pretreatment, and the strain/vector combination. The highest number of transgenic plants was obtained after transformation
with LBA4404(pTOK233) and kanamycin selection. Pretreatment of explants with picloram led to the highest number of plants
obtained after transformation with both Agrobacterium/vector systems LBA4404(pTOK233) and EHA101(pGAH) and selected with kanamycin. Transgenic character of selected plants was
examined by PCR using specific primers for bar, gus, nptII, and hpt and confirmed by Southern blot hybridization analysis. There was no GUS expression in T0 transgenic plants transformed with gus under p35S. However the GUS expression was detectable in the progeny of some lines. Only 30% of 46 transgenic lines showed
Mendelian segregation of GUS expressing to GUS not expressing plants. In the remaining 70% the segregation was non-Mendelian
and the rate was much lower than 3:1. Factors that might effect expression of transgenes in allohexaploid monocot species
are discussed. 相似文献
3.
Transgenic zoysiagrass (Zoysia japonica) plants obtained by Agrobacterium-mediated transformation 总被引:1,自引:0,他引:1
Zoysiagrass (Zoysia japonica Steud.) is an important turfgrass that spreads by stolons and rhizomes. By exploring the potential of direct shoot formation from stolons, we developed a straightforward and efficient transformation protocol without callus induction and propagation. Sterilized stolon nodes were infected and co-cultivated with Agrobacterium tumefaciens harboring pCAMBIA vectors. Hygromycin phosphotransferase gene (hph) was used as the selectable marker and hygromycin was used as the selection agent. Both green and albino shoots were directly regenerated from the infected stolon nodes 4–5 weeks after hygromycin selection. Greenhouse-grown plants were obtained 10–12 weeks after Agrobacterium-mediated transformation. Based on the number of transgenic plants obtained and the number of stolon nodes infected, a transformation frequency of 6.8% was achieved. Stable integration of the transgenes in the plant genome was demonstrated by PCR and Southern blot hybridization analyses. Expression of the transgenes was confirmed by RT-PCR analysis and GUS staining. The new transformation system opens up new opportunities for the functional characterization of genes and promoters and the development of novel germplasm in zoysiagrass. 相似文献
4.
An efficient and reproducible transformation method of sonication- assisted Agrobacterium-mediated transformation (SAAT) was developed for chickpea (Cicer arietinum L.). Agrobacterium tumefaciens (LBA4404) harboring pCAMBIA1305.2 was used to transform decapitated embryo explants of two cultivars of chickpeas. By using
a series of co-cultivation, callus induction, shoot initiation and root inducing media, a large number of transgenic plants
were recovered. Transient expressions of GUS gene were detected by X-Gluc histochemical assay in transformed tissues. DNA analysis of T0 and T1 plants by PCR and Southern
hybridization confirmed the integration of transgenes in initial and next generation transformants in different transgenic
lines. The transformation efficiency was more than two times higher in SAAT treatment than simple Agrobacterium without sonication. 相似文献
5.
6.
An efficient Agrobacterium-mediated method for transformation of popular Bangladeshi Indica rice genotypes has been developed. Mature embryo-derived calluses as well as immature embryos were used as the target material. Transgenic plant production frequency was higher using the immature embryos than mature embryo-derived calluses. However, 3-week-old mature embryo-derived calluses served as an excellent starting material. The super-binary vector (pTOK233) was generally more effective than the binary vector (pC1301-Xa21mSS) particularly with recalcitrant Bangladeshi genotypes such as BR22. However, transformation of the Japonica cultivar Taipei-309 was equally effective with either plasmid. Inclusion of acetosyringone (200M) in co-cultivation media proved essential for successful transformation and the optimum co-cultivation period found was to be 3days. A large number of morphologically normal, fertile transgenic plants were obtained which expressed gus as determined by histochemical staining. Integration of the hpt gene into the genome of transgenic plants was confirmed by molecular analysis. Mendelian inheritance of transgenes (hpt and gus gene) was observed in T1 progeny. 相似文献
7.
A rapid, efficient, routine system has been established forAgrobacterium tumefaciens-mediated production of hundreds of fertile transgenic plants from commercially important rice cultivars, including an indica
cultivar, Pusa Basmati 1. Calli induced from embryos of mature rice seeds were cocultivated withA. tumefaciens strain LBA4404 carrying the plasmid pTOK233, then exposed to hygromycin selection followed by an efficient regeneration system.
Based on the total number of calli co-cultivated, the transformation frequencies of independent transgenic rice plants including
cultivars Pusa Basmati 1, E-yi 105, E-wan 5 and Zhong-shu-wan-geng, were 13.5, 13.0, 9.1, and 9.3%, respectively. T1 seeds
were harvested within 7–8 mo of initiation of mature embryo cultures. Data from Southern hybridization analysis proved that
foreign genes on T-DNA were stably integrated into the rice genome at low copy/site numbers. Mendelian inheritance of the
transgenes was confirmed in T1 progeny. 相似文献
8.
Improved protocols for transformation of indica rice mediated by Agrobacterium tumefaciens 总被引:2,自引:0,他引:2
A highly efficient gene transfer method mediated by Agrobacterium tumefaciens was developed for Group I indica rice, which had been quite recalcitrant in tissue culture and transformation. Freshly isolated immature embryos from plants grown in a greenhouse were inoculated with A. tumefaciens LBA4404 that harbored super-binary vector pTOK233 or pSB134, which had a hygromycin-resistance gene and a GUS gene in the T-DNA. The efficiency of gene transfer varied with the kinds of gelling agents and the basic compositions of co-cultivation media. The highest activity of GUS after co-cultivation was observed when NB medium solidified with agarose was used. For the subsequent cultures, two types of media (modified NB and CC) were chosen to recover hygromycin-resistant cells efficiently. The transformation protocol thus developed worked very well in all of the varieties tested in this study, and the transformation frequency (number of independent hygromycin-resistant and GUS-positive plants per embryo) reached more than 30% in IR8, IR24, IR26, IR36, IR54, IR64, IR72, Xin Qing Ai 1, Nan Jin 11, and Suewon 258. Most of the transformants (T0) were normal in morphology and fertile. Stable integration, expression and inheritance of transgenes were demonstrated by molecular and genetic analysis of transformants in the T0 and T1 generations. For the recovery of multiple independent transgenic events from a single immature embryo, procedures were developed to section the embryo into as many as 30 pieces after non-selective cultures following co-cultivation. Transformants were then obtained from the pieces cultured on the selective media, and, in the highest case, more than seven independent transgenic plants per original embryo (transformation frequency of 738%) were produced. Thus, the efficiency of transformation was remarkably improved. 相似文献
9.
Kumar V Satyanarayana KV Sarala Itty S Indu EP Giridhar P Chandrashekar A Ravishankar GA 《Plant cell reports》2006,25(3):214-222
A system for genetic transformation of Coffea canephora by co-cultivation with Agrobacterium rhizogenes harbouring a binary vector has been developed. The objective of the present study was the genetic transformation and direct
regeneration of transformants through secondary embryos bypassing an intervening hairy root stage. Transformants were obtained
with a transformation efficiency up to 3% depending on the medium adjuvant used. A. rhizogenes strain A4 harbouring plasmid pCAMBIA 1301 with an intron uidA reporter and hygromycin phosphotransferase (hptII) marker gene was used for sonication-assisted transformation of Coffea canephora. The use of hygromycin in the secondary embryo induction medium allowed the selection of transgenic secondary embryos having
Ri T-DNA along with the T-DNA from the pCAMBIA 1301 binary vector. In addition transgenic secondary embryos devoid of Ri-T-DNA
but with stable integration of the T-DNA from the binary vector were obtained. The putative transformants were positive for
the expression of the uidA gene. PCR and Southern blot analysis confirmed the independent, transgenic nature of the analysed plants and indicated single
and multiple locus integrations. The study clearly demonstrates that A. rhizogenes can be used for delivering transgenes into tree species like Coffea using binary vectors with Agrobacterium tumefaciens T-DNA borders. 相似文献
10.
An efficient protocol for sugarcane (Saccharum spp. L.) transformation mediated by Agrobacterium tumefaciens 总被引:4,自引:0,他引:4
Arencibia Ariel D. Carmona Elva R. Tellez Pilar Chan Ming-Tsair Yu Su-May Trujillo Luis E. Oramas Pedro 《Transgenic research》1998,7(3):213-222
This is the first successful report of the recovery of morphologically normal transgenic sugarcane plants from co-cultivation of calluses with Agrobacterium tumefaciens. Transformation frequencies (total of transgenic plants/number of cell clusters) were between 9.4 × 10–3 and 1.15 × 10–2. In our experiments, both LBA4404 (pTOK233) and EHA101 (pMTCA3IG), carrying a super-binary vector or supervirulent strain, respectively, were successful for sugarcane transformation. We found that three main factors: (1) the use of young regenerable calluses as target explants; (2) induction and/or improvement of the A. tumefaciens virulence system with sugarcane cell cultures and (3) pre-induction of organogenesis or somatic-embryogenesis-like sexual embryos, seem to be crucial in order to increase the cells competence for T-DNA transfer process. Patterns generated by Southern hybridization confirmed that T-DNAs were randomly integrated into sugarcane genome without th e persistence of A. tumefaciens in the transgenic plants 相似文献
11.
Tang W 《Plant cell reports》2003,21(6):555-562
Additional virulence (vir) genes in Agrobacterium tumefaciens and sonication were investigated for their impact on transformation efficiency in loblolly pine (Pinus taeda L.). Mature zygotic embryos of loblolly pine were co-cultivated with disarmed A. tumefaciens strain EHA105 containing either plasmid vector pCAMBIA1301 or vector pCAMBIA1301 with an additional 15.8-kb fragment carrying extra copies of the Vir B, Vir C, and Vir G regions from the supervirulent plasmid pTOK47. pCAMBIA1301 contains hygromycin resistance and the beta-glucuronidase (GUS) reporter gene. Expression of GUS was observed after 3-6 days of co-cultivation, with peak expression at approximately 21 days. The highest numbers of GUS-expressing areas were visible up to 21 days after co-cultivation, declining rapidly thereafter. Both transient and stable transformation efficiencies increased when the explants were sonicated before co-cultivation and/or the additional virB, virC, and virG genes were included with the pCAMBIA1301 plasmid T-DNA. Use of the plasmid with additional vir genes and sonication dramatically enhanced the efficiency of Agrobacterium-mediated gene transfer not only in transient expression but also in the recovery of hygromycin-resistant lines. Stably transformed cultures and transgenic plants were produced from embryos transformed with A. tumefaciens EHA105 carrying pCAMBIA1301 or pCAMBIA1301+pTOK47 in the three families of loblolly pine. The presence of the introduced GUS and hygromycin phosphotransferase genes in the transgenic plants was confirmed by polymerase chain reaction and Southern hybridization analyses. 相似文献
12.
Al-Forkan M Power JB Anthony P Lowe KC Davey MR 《Cellular & molecular biology letters》2004,9(2):287-300
Morphologically normal, fertile transgenic plants were obtained by co-culturing embryogenic calli of the Bangladeshi Indica rice cultivars BR26 and Binni with Agrobacterium tumefaciens strain LBA4404 carrying the super binary vector pTOK233. Acetosyringone (100 microM) in the medium during co-culture (25-28 degrees C) and selection on hygromycin B (50 mg l(-1)) were essential for efficient transformation. Stable integration and expression of beta-glucuronidase, neomycin phosphotransferase and hygromycin phosphotransferase genes in regenerated plants were confirmed by histochemical and fluorometric assays, ELISA and Southern analysis. Two to 3 copies of T-DNA were integrated into regenerated plants; transgene expression did not correlate with gene copy number. Mendelian segregation of transgenes occurred in T1 seed progeny. 相似文献
13.
Meadow fescue (Festuca pratensis Huds.) is an important cool-season forage grass in Europe and Asia. We developed a protocol for producing meadow fescue transgenic
plants mediated by Agrobacterium tumefaciens transformation. Embryogenic calli derived from mature embryos were transformed with A. tumefaciens strain AGL1 carrying the binary vector pDM805, coding for the phosphinothricin acetyltransferase (bar) and β-glucuronidase (uidA) genes. Bialaphos was used as the selective agent throughout all phases of tissue culture. In total, 40 independent transgenic
plants were recovered from 45 bialaphos-resistant callus lines and an average transformation efficiency of 2% was achieved.
The time frame from infection of embryogenic calli with Agrobacterium to transferring the transgenic plants to the greenhouse was 18 weeks. In a study of 11 BASTA-resistant transgenic lines,
the uidA gene was expressed in 82% of the transgenic lines. Southern blot analysis revealed that 82% of the tested lines integrated
one or two copies of the uidA gene.
C. Gao and J. Liu contributed equally to the work. 相似文献
14.
P. Espinosa J. Lorenzo A. Iglesias L. Yabor E. Menéndez J. Borroto L. Hernández A. Arencibia 《Plant cell reports》2002,21(2):136-140
A procedure for producing pineapple [Ananas comosus (L.) Merr.] transgenic plants was developed that involved selection by micropropagation in temporary immersion bioreactors (TIBs). Pineapple calluses ranging in size from 1.5 mm to 2.0 mm that were co-cultivated with Agrobacterium tumefaciens strains AT2260 (pIG121Hm) and LBA4404 (pTOK233) for 24 h produced the highest percentage (40%) of GUS+ calluses. Phosphinothricin and hygromycin, but not kanamycin, were effective selection markers in TIBs. Large-scale transformation experiments with AT2260 (pHCA58) and AT2260 (pHCG59) resulted in up to a 6.6% efficiency of transgenic plant recovery. TIB technology was found to be more efficient for transgenic plant selection than conventional micropropagation. Polymerase chain reaction and genomic Southern blot analyses confirmed the non-chimeric nature of the transgenic plants recovered from TIBs. 相似文献
15.
Hai Ping Hong Hongyi Zhang Paula Olhoft Steve Hill Hunt Wiley Effie Toren Helke Hillebrand Todd Jones Ming Cheng 《In vitro cellular & developmental biology. Plant》2007,43(6):558-568
A regeneration and transformation system has been developed using organogenic calluses derived from soybean axillary nodes
as the starting explants. Leaf-node or cotyledonary-node explants were prepared from 7 to 8-d-old seedlings. Callus was induced
on medium containing either Murashige and Skoog (MS) salts or modified Finer and Nagasawa (FNL) salts and B5 vitamins with
various concentrations of benzylamino purine (BA) and thidiazuron (TDZ). The combination of BA and TDZ had a synergistic effect
on callus induction. Shoot differentiation from the callus occurred once the callus was transferred to medium containing a
low concentration of BA. Subsequently, shoots were elongated on medium containing indole-3-acetic acid (IAA), zeatin riboside,
and gibberellic acid (GA). Plant regeneration from callus occurred 90 ∼ 120 d after the callus was cultured on shoot induction
medium. Both the primary callus and the proliferated callus were used as explants for Agrobacterium-mediated transformation. The calluses were inoculated with A. tumefaciens harboring a binary vector with the bar gene as the selectable marker gene and the gusINT gene for GUS expression. Usually 60–100% of the callus showed transient GUS expression 5 d after inoculation. Infected
calluses were then selected on media amended with various concentrations of glufosinate. Transgenic soybean plants have been
regenerated and established in the greenhouse. GUS expression was exhibited in various tissues and plant organs, including
leaf, stem, and roots. Southern and T1 plant segregation analysis of transgenic events showed that transgenes were integrated into the soybean genome with a copy
number ranging from 1–5 copies. 相似文献
16.
Thellungiella halophila is a salt-tolerant close relative of Arabidopsis, which is adopted as a halophytic model for stress tolerance research. We established an Agrobacterium tumefaciens-mediated transformation procedure for T. halophila. Leaf explants of T. halophila were incubated with A. tumefaciens strain EHA105 containing a binary vector pCAMBIA1301 with the hpt gene as a selectable marker for hygromycin resistance and an intron-containing β-glucuronidase gene as a reporter gene. Following
co-cultivation, leaf explants were cultured on selective medium containing 10 mg l−1 hygromycin and 500 mg l−1 cefotaxime. Hygromycin-resistant calluses were induced from the leaf explants after 3 weeks. Shoot regeneration was achieved
after transferring the calluses onto fresh medium of the same composition. Finally, the shoots were rooted on half strength
MS basal medium supplemented with 10 mg l−1 hygromycin. Incorporation and expression of the transgenes were confirmed by PCR, Southern blot analysis and GUS histochemical
assay. Using this protocol, transgenic T. halophila plants can be obtained in approximately 2 months with a high transformation frequency of 26%. 相似文献
17.
This paper reports on the successful Agrobacterium-mediated transformation of oat, and on some factors influencing this process. In the first step of the experiments, three
cultivars, two types of explant, and three combinations of strain/vectors, which were successfully used for transformation
of other cereals were tested. Transgenic plants were obtained from the immature embryos of cvs. Bajka, Slawko and Akt and
from leaf base explants of cv. Bajka after transformation with A. thumefaciens strain LBA4404(pTOK233). The highest transformation rate (12.3%) was obtained for immature embryos of cv. Bajka. About 79%
of the selected plants proved to be transgenic; however, only 14.3% of the T0 plants and 27.5% of the T1 showed GUS expression. Cell competence of both types of explant differed in terms of their transformation ability and transgene
expression. The next step of the study was to test the suitability for oat transformation of the pGreen binary vector combined
with different selection cassettes: nptII or bar under the nos or 35S promoter. Transgenic plants were selected in combinations transformed with nos::nptII, 35S::nptII and nos::bar. The highest transformation efficiency (5.3%) was obtained for cv. Akt transformed with nos::nptII. A detailed analysis of the T0 plants selected from a given callus line and their progeny revealed that they were the mixture of transgenic, chimeric-transgenic
and non-transgenic individuals. Southern blot analysis of T0 and T1 showed simple integration pattern with the low copy number of the introduced transgenes. 相似文献
18.
19.
Agrobacterium tumefaciens-mediated transformation of japonica and indica rice varieties 总被引:1,自引:0,他引:1
Genetic transformation of rice (Oryza sativa L.) mediated by Agrobacterium ttumefaciens has been confirmed for japonica varieties and extended to include the more recalcitrant indica varieties. Immature embryos were inoculated with either A. tumefaciens At656 (pCNL56) or LBA4404 (pTOK233). Experimental conditions were developed initially for immature embryos treated with strain At656, based upon both transient and stable -glucuromdase (GUS) activities. However, plant regeneration following selection on G418 (pCNL56 contained the nptII gene) did not occur. Using the same basic protocol, but inoculating immature embryos of rice with LBA4404 (pTOK233), resulted in efficient (about 27%) production of transgenic plants of the japonica variety, Radon, and an acceptable efficiency (from 1–5%) for the indica varieties IR72 and TCS10. Transformation was based upon resistance to hygromycin (pTOK233 contains the hpt gene), the presence of GUS activity (from the gusA gene), Southern blots for detection of the integrated gusA gene, and transmission of GUS activity to progeny in a Mendelian 3:1 segregation ratio. Southern blots indicated two to three copies of the gene integrated in most transformants. Transgenic plants of both the japonica and indica varieties were self-fertile and comparable in this respect to seed-grown plants. Key factors facilitating the transformation of rice by Agrobacterium tumefaciens appeared to be the use of embryos as the expiant, the use of hygromycin as the selection agent (which does not interfere with rice regeneration), the presence of extra copies of certain vir genes on the binary vector of pTOK233, and maintaining high concentrations of acetosyringone for inducing the vir genes during co-cultivation of embryos with Agrobacterium.Abbreviations AS
acetosyringone
- DMRT
Duncan's Multiple Range Test
- GUS
-glucuronidase
- T-DNA
transferred DNA
We wish to thank Dr. Toshihiko Komari, Japan Tobacco Inc. for providing Ayrobacterium tumefaciens strain LBA4404 (pTOK322). Support by the Rockefeller Foundation in the form of a fellowship to R.R.A. and a grant to T.K.H. is acknowledged. This is journal paper number 14,914 from the Purdue University Agricultural Experiment Station. 相似文献