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1.
Katharina Hristoforoglu Josef Schmidt Harald Bolhar-Nordenkampf 《Plant Cell, Tissue and Organ Culture》1995,40(3):277-284
Mature zygotic embryos of Abies alba mull were placed on a modified MCM medium (basal medium-BM) with 2.2 M benzyladenine and 2.3 M kinetin to induce embryogenic suspensor masses (ESM). These ESM proliferated on induction medium supplemented with 0.2 M 2,4-dichlorophenoxyacetic acid. From 61 ESM lines induced, 36 are still in culture after 2 years, of which 18 show embryogenic potential indicated by spontaneous formation of globular somatic embryos on the proliferation medium supplemented with 500–1000 mg l-1 casein hydrolysate and 500 mg l-1
l-glutamine. ESMs from cell line 2/56 were conditioned 1 week on BM with 58 mM sucrose and 10 g l-1 activated charcoal for maturation of somatic embryos. Maturation was achieved on BM containing 20 M (±)cis-trans-abscisic acid in combination with 111 mM maltose. Organic nitrogen supplements improved the proliferation rate of cell line 2/56 as well as the maturation and vitality of the somatic embryos. Partial drying was necessary for subsequent root development. Plantlets with a root, primary needles and a terminal bud developed on BM when a combination of 30 mM sucrose and 50 mM maltose was provided as carbon source.Abbreviations BM
basal medium
- BA
benzyladenine
- ESM
embryogenic suspensor mass
- 2,4-d
2,4-dichlorophenoxyacetic acid
- CH
casein hydrolysate
-
l-gln
l-glutamine
- ABA
(±) cis-trans-abscisic acid 相似文献
2.
Y. W. Kim R. Newton J. Frampton K.-H. Han 《In vitro cellular & developmental biology. Plant》2009,45(4):400-406
Embryogenic suspensor mass (ESM) was established from immature seeds of Fraser fir. The initiation frequency of ESM was dependent
on genotype, collection time, medium, and plant growth regulators (PGR) used. The ESM initiation potential was higher with
seeds collected in late June (clone 16-273, 4.7%) or early July (clone 16-45, 2.2%) and decreased as the zygotic embryos matured.
Excised proembryo stage of zygotic embryos was most appropriate to initiation of ESM. Most of the ESM arose from the seeds
that were at the proembryo stage. From the four different culture media we compared, seven ESM lines were obtained: two lines
from Murashige and Skoog (MS) medium with 4.4 μM benzyladenine (BA), one from Schenk and Hildebrandt (SH) medium with 4.5 μM
thidiazuron (TDZ), and four from SH with 4.4 μM 6-benzyladenine. However, only one ESM line from clone 16-273 (June 24, SH+TDZ)
could be proliferated in subsequent culture. Different concentrations of l-glutamine and casein hydrolysate (CH) in the medium were also compared for their effect on ESM proliferation. The highest
proliferation rate (1.16-fold) was obtained from SH medium supplemented with 250 mg/L CH and 3.42 mM l-glutamine. In contrast, the lowest rate was noted when 1,000 mg/L CH plus 3.42 mM l-glutamine (0.17-fold) was added to the medium. As for somatic embryo maturation, the highest number of mature precotyledonary
(100.1/g−1 FW ESM) or cotyledonary (64.3/g−1 FW ESM) somatic embryos was obtained on a medium containing 20 or 80 μM abscisic acid, 10% polyethyleneglycol, 4% maltose,
and 0.3% gellan gum. For germination of the somatic embryos, the cotyledonary somatic embryos derived from maturation medium
were transferred on half-strength Litvay medium containing 0.3% gellan gum. The somatic plantlets were recovered from the
germination medium and transferred to soils. 相似文献
3.
A genetic transformation system has been developed for selected embryogenic cell lines of hybrids Abies alba × A. cephalonica (cell lines AC2, AC78) and Abies alba × A. numidica (cell line AN72) using Agrobacterium tumefaciens. The cell lines were derived from immature or mature zygotic embryos on DCR medium containing BA (1 mg l−1). The T-DNA of plant transformation vector contained the β-glucuronidase reporter gene under the control of double dCaMV 35S promoter and the neomycin phosphotransferase selection marker gene driven by the nos promoter. The regeneration of putative transformed tissues started approximately 1 week after transfer to the selection medium
containing 10 mg geneticin l−1. GUS activity was detected in most of the geneticin-resistant sub-lines AN72, AC2 and AC78, and the transgenic nature of
embryogenic cell lines was confirmed by PCR approach. Plantlet regeneration from PCR-positive embryogenic tissues has been
obtained as well. The presence of both gus and nptII genes was confirmed in 11 out of 36 analysed emblings. 相似文献
4.
Friable embryogenic callus and somatic embryo formation from cotyledon explants of African marigold (Tagetes erecta L.) 总被引:3,自引:0,他引:3
Embryogenic callus and somatic embryos were induced from cotyledonary explants of African marigold (Tagetes erecta L.). Cotyledons were first cultured on MS medium supplemented with 2.0 mg l–1 2,4-D and 0.2 mg l–1 kinetin. After 5 weeks, calli were transferred to MS medium supplemented with 0.02 mg l–1 thidiazuron where compact embryogenic callus developed. Friable embryogenic callus developed when the compact embryogenic
callus was transferred to medium containing 2,4-D and subcultured every 2 weeks. Friable embryogenic callus has been maintained
for more than 2 years without losing the capacity to generate embryos. Embryo development was obtained when friable embryogenic
callus was transferred to MS medium supplemented with 3 mg l–1 ABA and 60 g l–1 sucrose. The addition of 10–30 mM
l-glutamine improved embryo development.
Received: 13 May 1997 / Revision received: 24 February 1998 / Accepted: 28 March 1998 相似文献
5.
Kailash Choudhary M. Singh M. S. Rathore N. S. Shekhawat 《Plant biotechnology reports》2009,3(3):205-211
An efficient in vitro regeneration protocol for moth bean [Vigna aconitifolia (Jacq.) Marechal] via somatic embryogenesis has been developed. Embryogenic callus cultures were established from the cotyledonary
node as explant on semi-solid Murashige and Skoog (MS) medium supplemented with 0.75 mg l−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.5 mg l−1 6-benzylaminopurine (BA) and with various additives (50 mg l−1 ascorbic acid and 25 mg l−1 each of adenine sulphate, citric acid and l-arginine). Numerous somatic embryos differentiated on MS basal nutrient medium supplemented with 0.25 mg l−1 2,4-D and 0.5 mg l−1 of kinetin (Kin). Sustained cell division resulted in the formation of cell aggregates, which progressed to the globular-
and heart-shaped somatic embryos and then, if they differentiated properly, to the torpedo shape and cotyledonary stages.
The transfer of embryos onto fresh MS basal medium containing 0.2 mg l−1 BA and 2.0 mg l−1 gibberellic acid enabled the embryos to achieve complete maturation and germination. More than 80% of somatic embryos were
converted into true-to-type fertile plants. In vitro-regenerated plantlets with well-developed roots were successfully hardened
in a greenhouse and established in soil. 相似文献
6.
Mashitha Pise Jaishree Rudra Sunita Bundale Deovrat Begde Nandita Nashikkar Avinash Upadhyay 《In vitro cellular & developmental biology. Plant》2012,48(1):85-91
Asparagus racemosus is an important monocot medicinal plant that is in great demand for its steroidal saponins called shatavarins. This study
was initiated to optimize the conditions for production of shatavarins in cell cultures of A. racemosus in a modified Murashige and Skoog (MS) medium supplemented with six different combinations of growth regulators. Biomass
accumulation was correlated with saponin production over a 30-d culture cycle. Biomass and saponin accumulation patterns were
dependent on combinations of growth regulators and the pH of the medium. Maximum levels of saponin and biomass accumulation
were recorded on day 25 of the culture cycle within a pH range of 3.4 to 5.6. Total saponin produced by the in vitro cultures was 20-fold higher than amounts produced by cultivated plants. Saponin accumulation was not a biomass-associated
phenomenon; cultures which showed the highest biomass accumulation were not the highest saponin accumulators. Maximum biomass
(28.30 ± 0.29 g l−1) and maximum levels of shatavarin IV(11.48 ± 0.61 mg g−1) accumulation was found using a medium containing 2.0 mg l−1 2,4-D, 2 g l−1 casein hydrolysate and 0.005% pectinase. The highest levels of sarsapogenin, secreted and intracellular (4.02 ± 0.09 mg g−1), accumulated using a medium containing 1.0 mg l−1 NAA, 1.0 mg l−1 2,4-D, 0.5 mg l−1 BAP, 2 g l−1 casein hydrolysate and 0.005% pectinase, after 25 d. Shatavarins were secreted into the medium and can be isolated easily
for further purification. 相似文献
7.
Summary High-frequency embryogenesis systems were established for hybrid yellow-poplar (Liriodendron tulipifera×L. chinense) and hybrid sweetgum (Liquidambar styraciflua×L. formosana) by modifying a medium originally developed for embryogenic yellow-poplar cultures. Embryogenic cultures of both hybrids,
consisting of proembryogenic masses (PEMs), were initiated from immature hybrid seeds on an induction-maintenance medium (IMM)
supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D), benzyladenine (BA), and casein hydrolyzate (CH). For hybrid yellow-poplar,
as many as 2100 germinable somatic embryos per 4000 cells or cell clumps were produced when PEMs were grown in liquid IMM
lacking CH, at a pH that varied with genotype (3.5 or 5.6), followed by size fractionation and plating on semisolid embryo
development medium (DM; IMM lacking 2,4-D and BA) without CH, but supplemented with 4.0 mgl−1 (15 μM) abscisic acid. For hybrid sweetgum, up to 1650 germinable somatic embryos per 4000 cells or cell clumps were produced when
PEMs were grown in liquid IMM without CH, but with 550 mgl−1
l-glutamine, 510 mg l−1 asparagine, and 170 mg l−1 arginine at pH 5.6. Somatic embryos developed from cell clumps on DM without any plant growth regulators or other supplements.
Hundreds of somatic embryos of both hybrids were germinated on DM without CH, transferred to potting mix, and hardened off
in a humidifying chamber for transfer to the greenhouse. 相似文献
8.
Jatropha curcas L. (Physic nut) is a commercially important non-edible oil seed crop known for its use as an alternate source of biodiesel.
In order to investigate the morphogenic potential of immature embryo, explants from four developmental stages were cultured
on medium supplemented with combinations of auxins and cytokinins. It was found that the size of embryo is critical for the
establishment of callus. Immature embryos (1.1–1.5 cm) obtained from the fruits 6 weeks after pollination showed a good response
of morphogenic callus induction (85.7%) and subsequent plant regeneration (70%) with the maximum number of plantlets (4.7/explant)
on Murashige and Skoog’s (MS) medium supplemented with IBA (0.5 mg l−1) and BA (1.0 mg l−1). The above medium when supplemented with growth adjuvants such as 100 mg l−1 casein hydrolysate + 200 mg l−1
l-glutamine + 8.0 mg l−1 CuSO4 resulted in an even higher frequency of callus induction (100%). Plant regeneration (90%) with the maximum number of plantlets
(10/explant) was achieved on MS medium supplemented with 500 mg l−1 polyvinyl pyrrolidone + 30 mg l−1 citric acid + 1 mg l−1 BA + 0.5 mg l−1 Kn + 0.25 mg l−1 IBA. It was observed that plantlet regeneration could occur either through organogenesis of morphogenic callus or via multiplication
of pre-existing meristem in immature embryos. The age of immature embryos and addition of a combination of growth adjuvants
to the culture medium appear to be critical for obtaining high regeneration rates. Well-developed shoots rooted on half-strength
MS medium supplemented with 0.5 mg l−1 IBA and 342 mg l−1 trehalose. The rooted plants after acclimatization were successfully transferred to the field in different agro-climatic
zones in India. This protocol has been successfully evaluated on five elite lines of J. curcas. 相似文献
9.
Remi Nakagawa Shinjiro Ogita Takafumi Kubo Ryo Funada 《Plant Cell, Tissue and Organ Culture》2006,85(2):229-234
We examined the effects of polyamines, namely, putrescine, spermidine and spermine, and of amino acids, such as l-arginine and l-ornithine, as part of our efforts to identify factors that stimulate the development of proembryogenic masses (PEMs) of Cryptomeria japonica. We maintained two distinct types of PEM designated PEMs A, which consisted of normal embryogenic cells as single embryos with elongated suspensor cells, and PEMs B, which consisted of abnormal embryogenic cells with coalesced embryos on modified Campbell and Durzan medium (mCD) supplemented with individual polyamines at 0–100 μM or amino acids at 0–16.4 mM. All additives had a stimulatory/suppressive effect. Microscopy and image-processing techniques revealed that the regions of authentic embryos of PEMs that were treated with l-ornithine were remarkably enlarged and that the suspensor cells had elongated in the same direction. When all PEMs A were transferred to maturation medium (mCD that contained abscisic acid and maltose at various concentrations), only PEMs that had been treated with l-ornithine matured into somatic embryos and were able to germinate on hormone-free mCD. Our results indicate that l-ornithine is an important stimulator of the development of PEMs to the pre-filamentous stage in C. japonica. 相似文献
10.
Wei Tang Zhongchen Guo Fan Ouyang 《In vitro cellular & developmental biology. Plant》2001,37(5):558-563
Summary Mature zygotic embryos of eight (open-pollinated) families of loblolly pine (Pinus taeda L.) were cultured on eight different basal salt formulations, each supplemented with 36.2 μM 2,4-dichlorophenoxyacetic acid, 17.8 μM 6-benzyladenine, 18.6 μM kinetin, 500 mg l−1 casein hydrolysate, and 500 mg l−1
l-glutamine for 9 wk; embryogenic tissue was formed on cotyledons, hypocotyls, and radieles of mature zygotic embryos. Callus
was subcultured on the callus proliferation medium, the same as the induction medium but with one-fifth concentration of auxin
and cytokinin for 9 wk. On this medium a white to translucent, glossy, mucilaginous embryogenic callus containing embryogenic
suspensor masses (ESMs) was obtained. The highest frequency of explants forming embryogenic tissue, 17%, occurred on a modified
Murashige and Skoog salts basal medium containing the concentration of KNO3, Ca(NO3)2·4H2O, NH4NO3, KCl, ZnSO4·7H2O, and MnSO4·H2O, 720, 1900, 400, 250, 25.8, and 25.35 mg l−1, respectively. Embryogenic suspension cultures were established by culturing embryogenic callus in liquid callus proliferation
medium. Liquid cultures containing ESMs were transferred to medium containing abscisic acid, polyethylene glycols, and activated
charcoal for stimulating the production of cotyledonary somatic embryos. Mature somatic embryos germinated for 4–12 wk on
medium containing indole-butyric acid, gibberellic acid, 6-benzyladenine, activated charcoal, and reduced sucrose concentration
(15 g l−1). Two hundred and ninety-one regenerated plantlets were transferred to a perlite:peatmoss:vermiculite (1∶1∶1) mixture, then
the plants were transplanted to soil in the earth, and 73 plantlets survived in the field. 相似文献
11.
A simple protocol for direct shoot organogenesis and plant regeneration in Lessertia frutescens using hypocotyl and cotyledon segments is reported. l-canavanine content in the derived shoots is also quantified. Media containing different concentrations and combinations of
the cytokinins kinetin (K) and benzyladenine (BA) were tested for shoot induction potential. The best shoot regeneration rate
(83%) was obtained from hypocotyl segments cultured in Murashige and Skoog (MS) medium supplemented with 1 mg l−1 K; these hypocotyls also produced the largest number of shoots per explant (3.5) and the longest shoots per explant (13.3
mm). The best shoot regeneration rate (46%) using cotyledons as explant material was obtained in MS medium supplemented with
1 mg l−1 K and 1 mg l−1 BA or with 5 mg l−1 K and 0.5 mg l−1 BA. The highest number of cotyledon-derived shoots (1.5) was obtained in MS medium containing 2 mg l−1 K and 0.5 mg l−1 BA, and the longest cotyledon-derived shoots (6.1 mm) were obtained in MS medium containing 1 mg l−1 K and 0.5 mg l−1 BA. Shoots derived from hypocotyls cultured on media containing 1 mg l−1 K contained the highest quantity of l-canavanine (1.42 mg g−1) relative to the control (0.52 mg g−1). Shoots derived from cotyledons cultured on media containing 2 mg l−1 K contained the highest quantity of l-canavanine (2.07 mg g−1) compared to the control. Scanning electron microscopy revealed that shoots regenerated directly from the wounded epidermal
tissue, although callus formation was observed in most cultures. Young shoot clusters proliferated into healthy adventitious
shoots that were subsequently transferred directly onto rooting medium (MS medium containing 4 mg l−1 indole-3-butyric acid), eliminating the need for an additional multiplication or elongation phase. The in vitro plants were
successfully acclimatized in a growth chamber, achieving an 85% survival rate. 相似文献
12.
Zuzana Vondráková Kateřina Eliášová Lucie Fischerová Martin Vágner 《Central European Journal of Biology》2011,6(4):587-596
The somatic embryogenesis of conifers is a process susceptible to exogenous phytohormonal treatments. We report the effects
of the synthetic auxin 2,4-dichlorophenoxyacetic acid (2,4-D) and the auxin inhibitor p-chlorophenoxyisobutyric acid (PCIB) on the endogenous level of the auxin indole-3-acetic acid (IAA) and on the anatomical
composition of early somatic embryos of Abies alba (European silver fir). The embryogenic suspensor mass (ESM) of Abies alba proliferated on a medium supplemented by 2,4-D as well as on an auxin-free medium. The endogenous level of IAA was significantly
higher in the ESM cultivated on a medium supplemented by 2,4-D. The decrease in the endogenous level of IAA in the first week
of maturation is one of the most important stimuli responsible for the subsequent development of embryos. However, suppression
of IAA synthesis by an auxin inhibitor did not stimulate the development of embryos. The maturation of somatic embryos from
the globular to the cotyledonary stage occurs when the concentration of endogenous auxin in the ESM (including the embryos)
increases. Early somatic embryos proliferating on a medium supplemented by auxin had an increased probability of maturing
successfully. Exogenous auxin treatment during maturation did not compensate for the auxin deficiency during proliferation. 相似文献
13.
The cell cultures of Cayratia trifolia (Vitaceae) a tropical lianas, were maintained in Murashige and Skoog’s medium containing 0.25 mg l−1 naphthalene acetic acid, 0.2 mg l−1 kinetin and 250 mg l−1 casein hydrolysate. Cell suspension cultures of C. trifolia accumulate stilbenes (piceid, resveratrol, viniferin, ampelopsin) which on addition of 0.1–0.5 mg l−1 morphactin in the medium containing naphthalene acetic acid and kinetin declined. Morphactin or 2 isopentenyl adenine alone
at 0.1 mg l−1 concentration enhanced stilbenes which on combination markedly enhanced the yield to ~5 mg l−1 at 15th day. 相似文献
14.
Meiru Li Hongqing Li Xiaoying Hu Xiaoping Pan Guojiang Wu 《Plant Cell, Tissue and Organ Culture》2010,102(3):321-327
Zoysia tenuifolia Willd. ex Trin. is one of the most popularly cultivated turfgrass. This is the first report of successful plant regeneration
and genetic transformation protocols for Z. tenuifolia using Agrobacterium tumefaciens. Initial calli was induced from stem nodes incubated on a Murashige and Skoog (1962) (MS) medium supplemented with 2 mg l−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 1 mg l−1 6-benzyladenine (BA), with a frequency of 53%. Compact calli were selected and subcultured monthly on the fresh medium. Sixty-nine
percent of the calli could be induced to regenerate plantlets when the calli incubated on a MS medium supplemented with 0.2 mg l−1 BA under darkness. For genetic transformation, calli were incubated with A. tumefaciens strain EHA105 harboring the binary vector pCAMBIA 1301 which contains the hpt gene as a selectable marker for hygromycin resistance and an intron-containing β-glucuronidase gene (gus-int) as a reporter gene. Following co-cultivation, about 12% of the callus explants produced hygromycin resistant calli on
MS medium supplemented with 2 mg l−1 2,4-D, 1 mg l−1 BA, 50 mg l−1 hygromycin, 500 mg l−1 cefotaxime after 8 weeks. Shoots were regenerated following transfer of the resistant calli to shoot induction medium containing
0.2 mg l−1 BA, 50 mg l−1 hygromycin, and 250 mg l−1 cefotaxime, and about 46% of the resistant calli differentiated into shoots. Finally, all the resistant shoots were rooted
on 1/2 MS media supplemented with 50 mg l−1 hygromycin, 250 mg l−1 cefotaxime. The transgenic nature of the transformants was demonstrated by the detection of β-glucuronidase activity in the primary transformants and by PCR and Southern hybridization analysis. About 5% of the total
inoculated callus explants produced transgenic plants after approximately 5 months. The procedure described will be useful
for both, the introduction of desired genes into Z. tenuifolia and the molecular analysis of gene function. 相似文献
15.
Jaya Arora Shaily Goyal Kishan Gopal Ramawat 《In vitro cellular & developmental biology. Plant》2010,46(5):430-436
This report demonstrates the elicitation effect on growth and stilbene accumulation in cell cultures of Cayratia trifolia (Vitaceae) by an extract of the angiosperm parasite Cuscuta reflexa and salicylic acid in combination with sucrose feeding. Cell cultures of C. trifolia, a tropical liana, were maintained in liquid Murashige and Skoog's basal medium containing 0.25 mg l−1 naphthalene acetic acid, 0.2 mg l−1 kinetin with 3% sucrose and 250 mg l−1 casein hydrolysate. The cells treated with Cuscuta elicitor showed increased polyphenol oxidase activity with increasing concentration of the elicitor, while total phenol content
remained almost unchanged. Enhanced yield of stilbenes (∼8-fold) was recorded in the cells treated with 200 mg l−1
Cuscuta elicitor for 7 d. Optimum accumulation of stilbenes with a non-significant decrease in cell growth as compared with control
was recorded with the addition of 3% sucrose on the seventh day of cell culture. Addition of 3% sucrose with salicylic acid
at 500 μM and Cuscuta extract at 200 mg l−1 on the seventh day enhanced total stilbene yield up to 50.1 mg l−1, which was ∼14-fold higher than in control cultures. Piceid content increased ∼200-fold in such cultures. 相似文献
16.
Nisar Ahmad Hina Fazal Bilal Haider Abbasi Muhammad Rashid Tariq Mahmood Nighat Fatima 《Plant Cell, Tissue and Organ Culture》2010,102(1):129-134
The organogenic potential and antioxidant potential (1, 1-diphenyl-2-picrylhydrazyl-scavenging activity) of the medicinal
plant Piper nigrum L. (black pepper) were investigated. Callus induction and shoot regeneration were induced from leaf explants of potted plants
cultured on MS medium supplemented with different plant growth regulators. The best callogenic response was observed on explants
cultured for 30 days on MS medium supplemented with either 0.5 or 1.5 mg l−1 6-benzyladenine (BA) + 1.0 mg l−1 α-naphthaleneacetic acid. Subsequent transfer of the callogenic explants onto MS medium supplemented with 1.5 mg l−1 BA + 1.0 mg l−1 gibberellic acid (GA3) achieved 85% shoot organogenesis after 30 days of culture. The maximum number (7.2) of shoots/explant was recorded for explants
cultured in MS medium supplemented with 1.0 mg l−1 BA. Following the transfer of shoots to an elongation medium, the longest shoots (5.4 cm) were observed on MS medium supplemented
with 1.0 mg l−1 BA + 1.0 mg l−1 GA3. The elongated shoots were rooted on MS medium supplemented with different concentrations of indole butyric acid. An assay
of the antioxidant potential of the in vitro-grown tissues revealed that the antioxidant activity of the regenerated shoots
was significantly higher than that of callus and the regenerated plantlets. 相似文献
17.
Summary
In vitro regeneration of plants via somatic embryogenesis through cell suspension culture was achieved in horsegram. Embryogenic calluses
were induced on leaf segments on solid Murashige and Skoog (MS) medium with 9.0 μM 2,4-dichlorophenoxyacetic acid (2,4-D). Differentiation of somatic embryos occurred when the embryogenic calluses were transferred
to liquid MS medium containing 2,4-D. Maximum frequency (33.2%) of somatic embryos was observed on MS medium supplemented
with 7.9 μM 2,4-D. Cotyledonary-torpedo-shaped embryos were transferred to liquid MS medium without growth regulators for maturation
and germination. About 5% of the embryos germinated into plants, which grew further on solid MS medium. The plants were hardened
and established in soil. Effects of various auxins, cytokinins, carbohydrates, amino acids, and other additives on induction
and germination of somatic embryos were also studied. A medium supplemented with 7.9 μM 2,4-D, 3.0% sucrose, 40 mg l−1
L-glutamine, and 1.0 μM abscisic acid was effective to achieve a high frequency of somatic embryo induction, maturation, and further development. 相似文献
18.
A genetic transformation system has been developed for callus cells of Crataegus
aronia using Agrobacterium
tumefaciens. Callus culture was established from internodal stem segments incubated on Murashige and Skoog (MS) medium supplemented with
5 mg l−1 Indole-3-butyric acid (IBA) and 0.5 mg l−1 6-benzyladenine (BA). In order to optimize the callus culture system with respect to callus growth and coloration, different
types and concentrations of plant growth regulators were tested. Results indicated that the best average fresh weight of red
colored callus was obtained on MS medium supplemented with 2 mg l−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.5 mg l−1 kinetin (Kin) (callus maintenance medium). Callus cells were co-cultivated with Agrobacterium harboring the binary plasmid pCAMBIA1302 carrying the mgfp5 and hygromycin phosphotransferase (hptII) genes conferring green fluorescent protein (GFP) activity and hygromycin resistance, respectively. Putative transgenic calli
were obtained 4 weeks after incubation of the co-cultivated explants onto maintenance medium supplemented with 50 mg l−1 hygromycin. Molecular analysis confirmed the integration of the transgenes in transformed callus. To our knowledge, this
is the first time to report an Agrobacterium-mediated transformation system in Crataegus
aronia. 相似文献
19.
Microbial production of L -glutamate and L -glutamine by recombinant Corynebacterium glutamicum harboring Vitreoscilla hemoglobin gene vgb 总被引:1,自引:0,他引:1
Liu Q Zhang J Wei XX Ouyang SP Wu Q Chen GQ 《Applied microbiology and biotechnology》2008,77(6):1297-1304
Vitreoscilla hemoglobin (VHb) gene vgb equipped with a native promoter Pvgb or a tac promoter Ptac was introduced into Corynebacterium glutamicum ATCC14067, respectively. Ptac was proven to be more suitable for expressing VHb protein in higher concentration in both Escherichia coli and C. glutamicum strains compared with the native vgb promoter Pvgb. VHb-expressing C. glutamicum exhibited higher oxygen uptake rate and enhanced cell growth. Recombinant C. glutamicum harboring vgb gene equipped with Ptac promoter produced 23% more l-glutamate in shake-flask culture and grew to 30% more cell density and formed 22% more l-glutamate in fermentor studies compared with the wild-type strain. When a site-directed mutagenesis in which Tyr405 was replaced
by a phenylalanine residue (Y405F) was performed on glutamine synthesis gene, recombinant C. glutamicum overexpressing the mutated gene glnA′ was able to produce l-glutamine effectively. Co-expression of vgb and glnA′ genes in C. glutamicum produced 17 g/l l-glutamine in shake flask culture, approximately 30% more than that produced by the recombinant harboring only glnA′ gene. In fermentor cultivation, the recombinant yielded 25% more cells and produced 40.5 g/l l-glutamine. In this study, it was clearly demonstrated that VHb significantly enhanced cell growth, l-glutamate, and l-glutamine production by recombinant C. glutamicum. 相似文献
20.
A. M. Vieitez E. Corredoira A. Ballester F. Muñoz J. Durán M. Ibarra 《Plant Cell, Tissue and Organ Culture》2009,98(2):135-145
North American oak species, with their characteristic strong episodic seasonal shoot growth, are highly problematic for clonal
micropropagation, resulting in the inability to achieve a stabilized shoot multiplication stage. The potential for initiating
and proliferating shoot cultures derived from Quercus alba, Q. bicolor and Q. rubra explants was investigated, and a micropropagation method for these species was developed. Branch segments from 6 to 7-year-old
trees were forced-flushed and the forced shoots were used as source of explants for culture initiation. A consistent shoot
multiplication stage was achieved, in 13 of the 15 genotypes established in vitro, although marked differences occurred in
explants from different genotypes/species. The control of efficient shoot multiplication involved the culture of decapitated
shoots in a stressful horizontal position on cytokinin-containing medium with a sequence of transfers within a 6-week subculture
cycle, which was beneficial to overcoming the episodic character of shoot growth. During each subculture cycle, the horizontally
placed explants were cultured on media containing 0.2 mg l−1 benzyladenine (BA) for 2 weeks with two successive transfers (2 weeks each) to fresh medium with 0.1 mg l−1 BA, giving a 6-week subculture cycle. The general appearance and vigor of Q. alba and Q. bicolor shoot cultures were improved by the inclusion of both 0.1 mg l−1 BA and 0.5 mg l−1 zeatin in the medium used for the second transfer within the 6-week subculture cycle. Addition of AgNO3 (3 mg l−1) to the shoot proliferation medium of Q. rubra had a significant positive effect on shoot development pattern by reducing deleterious symptoms, including shoot tip necrosis
and early senescence of leaves. The three species showed acceptable in vitro rooting rates by culturing microcuttings in medium
containing 25 mg l−1 indolebutyric acid for 48 h with subsequent transfer to auxin-free medium supplemented with 0.4% activated charcoal. Although
an initial 5-day dark period generally improved the rooting response, it was detrimental to the quality of regenerated plantlets.
However, activated charcoal stimulated not only the rooting frequencies, but it also enhanced plant quality, as evidenced
by root, shoot and leaf growth. 相似文献