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1.
J.M.R. Victor B.N.S. Murthy S.J. Murch S. KrishnaRaj P.K. Saxena 《Plant Growth Regulation》1999,28(1):41-47
Somatic embryogenesis was induced at the hypocotyledonary notch region of intact peanut (Arachis hypogaea L.) seedings cultured on a medium containing 10 mol·L–1 thidiazuron (TDZ). Inclusion of the purine analogs 2,6-diaminopurine (DAP), azaadenine or azaguanine to the thidiazuron amended medium inhibited the embryogenic response of the seedlings. DAP-mediated inhibition was not overcome by the addition of adenine sulphate. Inhibition of the embryogenic response by DAP provides evidence that the TDZ-induced accumulation of purine cytokinins is an essential component of TDZ-induced somatic embryogenesis process. Analyses of the endogenous level of purine metabolites indicated that supplementation of the media with TDZ resulted in an overall increase in the endogenous cytokinins while DAP inhibited the purine recycling resulting in decreased levels of endogenous adenine and zeatin. 相似文献
2.
In planta differentiation of somatic embryos was induced in seedlings of peanut (Arachis hypogaea L.) obtained from mature seeds germinated on a medium supplemented with thidiazuron (TDZ: N-phenyl-N1- (1,2,3 thiadiazol-yl)urea). At optimum levels of TDZ (10 M), all germinating seeds produced embryogenic seedlings, and somatic embryos developed in the apical region and on the surface of cotyledons and hypocotyls. These somatic embryos matured, germinated, and formed shoots which eventually developed into whole plants. Thidiazuron-induced direct embryogenesis from morphologically intact seedlings may provide an excellent experimental system for investigating somatic embryogenesis and the morphoregulatory role of TDZ.Abbreviations 2,4-D
2,4-dichlorophenoxyacetic acid
- MS
Murashige and Skoog (1962) medium
- TDZ
thidiazuron (N-phenyl-N1(1,2,3 thiadiazol-yl)urea)
This research was supported by an operating grant from the Natural and Engineering Research Council of Canada to P.K.S. We thank Drs. J.A. Qureshi and Judith Strommer for helpful discussions, and Sangeeta Saxena for technical assistance. A gift of technical-grade thidiazuron from Nor-Am Chemical Co., Wilmington, Del., USA is gratefully acknowledged. 相似文献
3.
Endogenous hormonal content and somatic embryogenic capacity of Corylus avellana L. cotyledons 总被引:2,自引:0,他引:2
Endogenous indole-3-acetic acid (IAA), abscisic acid (ABA) and cytokinins [zeatin (Z) zeatin riboside, dihydrozeatin, dihydrozeatin
riboside, N6-isopentenyl adenine (iP) and N6-isopentenyladenine riboside] were evaluated in hazelnut (Corylus avellana L.) cotyledons of different developmental stage and genetic source for their somatic embryogenic capacity. There was an inverse
correlation between the embryogenic potential of cotyledons and the degree of maturity of zygotic embryos, the first characteristic
being associated with iP-type cytokinins and the second with Z-type cytokinins. Although the differences in total cytokinin,
ABA and IAA contents between the cotyledons were small, the IAA/ABA and, mainly, the iP-type/Z-type cytokinin ratios were
found to be two good indexes of the embryogenic competence of explants, suggesting that the endogenous hormonal balance is
a very important factor defining the in vitro potential of hazelnut cotyledons.
Received: 6 January 1997 / Revision received: 3 March 1997 / Accepted 1 April 1997 相似文献
4.
Summary The ability of forchlorfenuron (CPPU), a substituted phenylurea compound, for inducing somatic embryogenesis in peanut (Arachis hypogaea L.) seedlings has been demonstrated. CPPU promoted somatic embryogenesis at a range of concentrations in all three peanut cultivars tested. Embryogenic response was dependent on applied CPPU concentrations. Exposure of seedlings for only two days to CPPU induced somatic embryogenesis, but the most effective treatment was to induce seed germination on media supplemented with either 2.5 or 4.0 M CPPU and to maintain the seedlings on the same medium. Number of somatic embryos and the frequency of embryogenesis was higher for younger seedlings (up to 9 days), regardless of the CPPU concentrations and seedlings older than 21 days failed to produce somatic embryos. Removal of cotyledons from the seeds drastically reduced the embryogenic potential of the seedlings. Somatic embryos developed into whole plants following their separation and subculture on a medium lacking growth regulators. The induction of somatic embryos using CPPU as a sole growth regulator may provide a useful system to study the role of this compound in plant morphogenesis.Abbreviations CPPU
N-(2-chloro-4-pyridyl)-N'-phenylurea
- DPU
N,N'-diphenylurea
- IAA
Indole-3-acetic acid 相似文献
5.
Immature seeds, as well as hypocotyls and cotyledons excised from seedlings of Myrtus communis L., were cultured on media containing half-strength Murashige and Skoog macronutrients (MS/2) with combinations of auxins
and cytokinins, in order to study their morphogenetic competence. Somatic embryogenesis was obtained from cotyledons, hypocotyls
and 2-month-old immature seeds with 0.1 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D). The percentage of explants showing this
primary somatic embryogenesis ranged from 4% for hypocotyls to 12% for 2-month-old immature seeds. In the latter, somatic
embryogenesis was also obtained in media containing 2,4-D plus a cytokinin, and with only a cytokinin. Somatic embryos obtained
from hypocotyls, cotyledons or immature seeds were able to develop on MS/2 medium without plant growth regulators. Subculture
of primary somatic embryos obtained from immature seeds on MS/2 medium without plant growth regulators gave rise to clusters
with secondary somatic embryos and embryogenic calli. These clusters were subcultured every 8 weeks, and they were the source
of highly embryogenic cultures. An average of 10% of the secondary somatic embryos developed into plantlets in each subculture.
Therefore, the same culture on MS/2 medium without growth regulators yielded both plantlets and de novo secondary embryos.
Received: 6 April 1998 / Revision received: 10 July 1998 / Accepted: 21 July 1998 相似文献
6.
Jinfeng Lü Rong Chen Muhan Zhang Jaime A. Teixeira da Silva Guohua Ma 《Journal of plant physiology》2013
Camellia nitidissima Chi (Theaceae) is a world-famous economic and ornamental plant with golden-yellow flowers. It has been classified as one of the rarest and most endangered plants in China. Our objective was to induce somatic embryogenesis, shoot organogenesis and plant regeneration for C. nitidissima. Three types of callus (whitish, reddish and yellowish) were induced from immature cotyledons on improved woody plant medium (WPM) with different plant growth regulators (PGRs). Among the callus, whitish callus was induced by 4.5 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and reddish and yellowish callus were induced by strongly active cytokinins, thidiazuron (TDZ) or 6-benzylaminopurine (BAP), singly or combined with weakly active auxin, α-naphthaleneacetic acid (NAA). The embryogenic callus could differentiate into somatic embryos, nodular embryogenic structures (large embryo-like structures) or adventitious shoots depending on the PGR used in WPM. BAP was best for adventitious buds and zeatin was best for somatic embryogenesis while kinetin (Kt) was best for the formation of nodular embryogenic structures. The three regeneration pathways often occurred in the same embryogenic callus clumps. Most shoots (80.0%) developed roots in WPM supplemented with 24.6 μM IBA and 0.3 μM NAA while 47.5% of somatic embryos could germinate directly and develop into plantlets on induction medium supplemented with 0.9 μM BAP and 0.1 μM NAA. The nodular embryogenic structures could be sub-cultured and cyclically developed in one of two differentiation pathways: shoot organogenesis or somatic embryogenesis. Plantlets derived from shoot buds rooted and somatic embryos germinated when transplanted into soil in a greenhouse; 66.7% of plantlets from shoot culture and 78.6% of plantlets from somatic embryos survived after 8 weeks’ acclimatization. 相似文献
7.
Chun-Lai Zhang Dong-Fang Chen Marie Kubalakova Jian Zhang Nigel W. Scott Malcolm C. Elliott Adrian Slater 《Plant Cell, Tissue and Organ Culture》2008,93(2):209-221
Efficient regeneration via somatic embryogenesis (SE) would be a valuable system for the micropropagation and genetic transformation
of sugar beet. This study evaluated the effects of basic culture media (MS and PGo), plant growth regulators, sugars and the
starting plant material on somatic embryogenesis in nine sugar beet breeding lines. Somatic embryos were induced from seedlings
of several genotypes via an intervening callus phase on PGo medium containing N6-benzylaminopurine (BAP). Calli were mainly induced from cotyledons. Maltose was more effective for the induction of somatic
embryogenesis than was sucrose. There were significant differences between genotypes. HB 526 and SDM 3, which produced embryogenic
calli at frequencies of 25–50%, performed better than SDM 2, 8, 9 and 11. The embryogenic calli and embryos produced by this
method were multiplied by repeated subculture. Histological analysis of embryogenic callus cultures indicated that somatic
embryos were derived from single- or a small number of cells. 2,4-dichlorophenoxyacetic acid (2,4-D) was ineffective for the
induction of somatic embryogenesis from seedlings but induced direct somatic embryogenesis from immature zygotic embryos (IEs).
Somatic embryos were mainly initiated from hypocotyls derived from the cultured IEs in line HB 526. Rapid and efficient regeneration
of plants via somatic embryogenesis may provide a system for studying the molecular mechanism of SE and a route for the genetic
transformation of sugar beet. 相似文献
8.
Xingyu Yang Jinfeng Lü Jaime A. Teixeira da Silva Guohua Ma 《Plant Cell, Tissue and Organ Culture》2012,109(2):213-221
Primulina tabacum is a rare and endangered species that is endemic to China. Establishing an efficient regeneration system is necessary for
its conservation and reintroduction. In this study, when leaf explants collected from plants grown in four ecotypes in China
are incubated on Murashige and Skoog (MS) medium containing 5.0 μM thidiazuron (TDZ) for 30 days, then transferred to medium
containing 5.0 μM 6-benzyladenine (BA), adventitious shoots are then observed. Conversely, when leaf explants are incubated
on medium containing 5.0 μM BA for 30 days, then transferred to medium containing 5.0 μM TDZ, somatic embryogenesis is induced.
This indicates that somatic embryogenesis and shoot organogenesis could be switched simply by changing the order of two cytokinins
supplemented in the culture medium. Histological investigation has revealed that embryogenic cells are induced within 30 days
following incubation of explants in medium containing TDZ. Only if embryogenic cells were induced, TDZ could enhance somatic
embryogenesis and BA could stimulate shoot organogenesis. When comparing explants from different ecotypes, leaf explants
from Zixiadong in Hunan Province could induce low numbers (1–2) of either somatic embryos or adventitious shoots on medium
containing either 5.0 μM TDZ or 5.0 μM BA, respectively. Whereas, leaf explants from plants collected from the other three
ecological habitats could induce 50–70 somatic embryos/adventitious shoots per explant. Moreover, somatic embryos could induce
secondary somatic embryogenesis and adventitious shoots on different media. All regenerated shoots developed adventitious
roots when these are transferred to rooting medium, and over 95% of plantlets have survived following acclimatization and
transfer to a potting mixture (1:1, sand:vermiculite). 相似文献
9.
植物激素对棉花体细胞胚胎发生的诱导及调节作用 总被引:19,自引:0,他引:19
选用11种激素研究了外源激素对棉花胚性愈伤组织增殖、胚胎发生和发育的调控作用。结果表明不同激素对棉花胚性愈伤组织增殖、胚胎发生与发育的影响不同。除2,4-D和BA对棉花胚性愈伤组织的增殖影响不大外,其他激素对棉花胚性愈伤组织的增殖均具有抑制作用,且具有一定的时间效应,同时还受基因型的影响。激素对棉花体细胞胚的形成和发育的影响极大,2,4-D既抑制了体细胞胚的形成,又抑制了体细胞胚的发育;TDZ的作用与2,4-D相似,显抑制了体细胞胚的形成,且诱导获得的体细胞胚均停留在球形胚阶段;GA也抑制了体细胞胚的形成,且不利于体细胞的成熟与萌发;BU-30对棉花体细胞胚形成与发育的影响不大。其他7类生长素类物质和细胞分裂素类物质对棉花体细胞胚的形成均具有促进作用,且依IBA、ABA、IAA、BA、KT、ZT、2iP序增强,其总胚数为对照的1.193—3.852倍;其中2iP的促进作用最大,可使产生的体细胞胚数提高2.852倍。 相似文献
10.
Somatic embryo formation occurred on leaf callus of grape (Vitis vinifera cv. Koshusanjaku). An embryogenic callus was induced from somatic embryo clusters cultured on vitamin-, inositol- and glycine-free Nitsch and Nitsch (1969) medium supplemented with 1.0M 2,4-D. This callus has retained a high embryogenic activity after repeated subculture on the same medium for over two years, and has produced numerous embryos after transfer to a hormone-free medium. The effect of cytokinin treatment on somatic embryogenesis from leaf callus was also examined. N-(2-chloro-4-pyridyl)-N-phenylurea (KT-30) and N-(1,2,3-thiadiazol-5-yl)-N-phenylurea (TAG), both synthetic cytokinins, were found to be effective for the induction of somatic embryogenesis. When leaf callus was induced by these cytokinins combined with 2,4-D at either 5.0 or 10.0M, somatic embryos were produced.Abbreviations B5
Basal medium, Gamborg et al. (1968)
- BA
6-benzylaminopurine
- 2,4-D
2,4- dichlorophenoxyacetic acid
- IAA
indole-3-acetic acid
- 2iP
(2-isopentenyl)adenine
- KIN
kinetin
- KT-30
N-(2-chloro-4-pyridyl)-N'-phenylurea, also called 4PU-30, Kyowa Hakko Kogyo Co., Japan
- NAA
1-naphthaleneacetic acid
- NN
Basal medium, Nitsch and Nitsch (1969)
- MS
Basal medium, Murashige and Skoog (1962)
- TAG
N-(1,2,3-thiadiazol-5-yl)-N'-phenylurea, also called thidiazuron or TDZ, Tomono Noyaku Co., Japan
- ZEA
zeatin 相似文献
11.
Summary Thidiazuron (TDZ) effectively induced somatic embryogenesis in cultured hypocotyl explants of geranium (Pelargonium x hortorum Bailey) during only a 3-day period of induction. The presence of acetylsalicylic acid (ASA) during this period caused a two-fold increase in the number of somatic embryos and enhanced synchronization of embryo development compared to the TDZ treatment alone. Salicylic acid was ineffective in modulating similar embryogenic responses as ASA. The ASA-induced enhancement and synchronization of somatic embryogenesis could possibly be used as an experimental system to study the interplay of growth regulators in somatic embryogenesis.Abbreviations ASA
acetylsalicylic acid
- SA
salicylic acid 相似文献
12.
Chun-Lai Zhang Dong-Fang Chen Malcolm C. Elliott Adrian Slater 《In vitro cellular & developmental biology. Plant》2001,37(2):305-310
Summary Improved in vitro tissue culture systems are needed to facilitate the application of recombinant DNA technology to the improvement of sugar
beet germplasm. The effects of N
6-benzyladenine (BA) and thidiazuron (TDZ) pretreatment on adventitious shoot and somatic embryogenesis regeneration were evaluated
in a range of sugar beet breeding lines and commercial varieties. Petiole explants showed higher frequencies of direct adventitious
shoot formation and produced more shoots per explant than leaf lamina explants. TDZ was more effective than BA for the promotion
of shoot formation. The optimal TDZ concentrations were 2.3–4.6 μM for the induction of adventitious shoot regeneration. Direct somatic embryogenesis from intact seedlings could be induced
by either BA or TDZ. TDZ-induced somatic embryogenesis occurred on the lower surface of cotyledons at concentrations of 0.5–2μM and was less genotype-dependent than with Ba. A high frequency of callus induction could be obtained from seedlings and leaf
explants, but only a few of the calluses derived from leaf explants could regenerate to plants via indirect somatic embryogenesis. These results demonstrated that TDZ could prove to be a more effective cytokinin for in vitro culture of sugar beet than BA. Rapid and efficient regeneration of plants using TDZ may provide a route for the production
of transgenic sugar beet following Agrobacterium-mediated transformation. 相似文献
13.
L. Sáenz A. Azpeitia C. Oropeza L. H. Jones K. Fuchsova L. Spichal M. Strnad 《Plant cell reports》2010,29(11):1227-1234
Auxin induces in vitro somatic embryogenesis in coconut plumular explants through callus formation. Embryogenic calli and
non-embryogenic calli can be formed from the initial calli. Analysis of endogenous cytokinins showed the occurrence of cytokinins
with aromatic and aliphatic side chains. Fourteen aliphatic cytokinins and four aromatic cytokinins were analysed in the three
types of calli and all the cytokinins were found in each type, although some in larger proportions than others. The most abundant
cytokinins in each type of callus were isopentenyladenine-9-glucoside, zeatin-9-glucoside, zeatin riboside, isopentenyladenine
riboside, dihydrozeatin and dihydrozeatin riboside in decreasing order. Total cytokinin content was compared between the three
types of calli, and it was found to be lower in embryogenic calli compared to non-embryogenic calli or initial calli. The
same pattern was observed for individual cytokinins. When explants were cultured in media containing exogenously added cytokinins,
the formation of embryogenic calli in the explants was reduced. When 8-azaadenine (an anticytokinin) was added the formation
of embryogenic calli and somatic embryos was increased. These results suggest that the difference in somatic embryo formation
capacity observed between embryogenic calli and non-embryogenic calli is related to their endogenous cytokinin contents. 相似文献
14.
Elena Gutierrez Piedad Gallego Angel Alonso Antonio Blazquez Luisa Martin Javier Fernandez Leticia Dominguez Cristina Rioja Hilario Guerra Nieves Villalobos 《In vitro cellular & developmental biology. Plant》2010,46(3):257-264
Nitrogen (N) metabolism during embryogenesis may be fundamental in the embryogenic response. We used different explants of
Medicago arborea L. subsp. arborea seedlings: cotyledons, petioles and leaves, which form calluses with different embryogenic responses. The endogenous contents
of total nitrogen, nitrate, nitrite and ammonia and nitrate reductase activity were determined in embryogenic and non-embryogenic
calluses induced from the different explants. The endogenous total N content decreased in the calluses as the culture time
progressed, this decrease being more pronounced in the more embryogenic calluses obtained from petioles with the H8 and F0
media. Inorganic N decreased during embryogenesis, coinciding with an increase in organic N. Thus, N metabolism somehow seems
to be essential in embryogenesis. The N detected in calluses, at the start of culture, was mainly metabolised to nitrite.
This metabolism was very pronounced; especially in embryogenic calluses obtained from cotyledons and petioles. That is, the
metabolism of N seemed to be more marked in the calluses in which embryogenesis was greater. The nitrite content decreased
in all the calluses, the contents being lower, especially in the last months of culture, in the more embryogenic calluses
obtained from petioles. In many calluses, ammonia levels did not follow any general pattern. Neither was it possible to detect
changes in ammonia levels between the embryogenic and non-embryogenic calluses. Regarding nitrate reductase activity, no clear
differences between embryogenic and non-embryogenic calluses were found. 相似文献
15.
16.
To maintain embryogenic cell lines ofPimpinella brachycarpa, we suspension-cultured friable and rapidly growing yellowish calli in an MS liquid medium containing 0.2 ~ 2,4-D and 0.5pM BAP. Efficient somatic embryogenesis was achieved when selected cells were then transferred to an MS medium (0.2% gelrite)
that contained 0.2gM 2,4-D, 0.5 uM BAP, and 10.0 laM TDZ (thidiazuron). These cells were cultured at 27°C under continuous illumination (21.5
I~E m-2 s-l). Embryogenic calli expanded about four-fold, and developed into pale yellow calli. Somatic embryogenesis was initiated only
from glossy and nodular-type calli. After two more weeks of culture, globular embryos appeared on the surface of calli grown
in the MS medium that contained 10.0 /aM TDZ only, or in combination with 0.5 gM NAA. Experimenting with 2,4-D, an auxin,
to promote embryogenic calli resulted in excessive browning and death. We overcame this problem by growing glossy embryogenic
and nodular calli on media that contained 10.0 gM TDZ. Calli that were not treated with TDZ turned dark brown and were not
viable. Up to 74% of the calli showed somatic embryos when the medium was supplemented with 10.0 uM TDZ and 0.5 uM NAA. Embryos
from these TDZ-induced, somatic embryogenic calli grew efficiently, forming multiple shoots and developing into normal plants.
Therefore, efficient differentiation of suspension-cultured cell clusters into embryogenic calli, along with treatment of
subsequent somatic embryos by TDZ, suggests that TDZ probably helps in establishing the optimum cytokinin-auxin ratio required
for induction and expression of somatic embryogenesis. 相似文献
17.
Aneta Ivanova Margarita Velcheva Plamen Denchev Atanas Atanassov Henri A. Van Onckelen 《Physiologia plantarum》1994,92(1):85-89
Endogenous indole-3-acetic acid, abscisic acid and cytokinins (zeatin, zeatin riboside, N-isopentenyladenine and N-isopentenyladenosine) were evaluated in initial explants (leaves) of in vitro propagated plants of alfalfa ( Medicago falcata L.) lines varying in embryogenic capacity and during the somatic embryogenesis process. Fast embryo-genic induction was correlated with high IAA and low ABA levels in the initial explants. No significant differences were observed in the cytokinin contents. Our results suggest that a certain hormone balance is necessary to allow the expression of the embryogenic potential. The consistent stages of the direct somatic embryogenesis are also characterized by changes in hormonal levels. 相似文献
18.
Somatic embryogenesis in wild cherry (Prunus avium) 总被引:3,自引:0,他引:3
Garin Elisabeth Grenier Emmanuel Grenier-De March Ghislaine 《Plant Cell, Tissue and Organ Culture》1997,48(2):83-91
Indirect somatic embryogenesis was obtained inPrunus avium L. from either somatic or zygotic embryos. An embryogenic line
was established by reinduction of embryogenic calluses from somatic embryos. The line was maintained for more than 3 years
through 6 generations of embryogenic cultures. In the last 2 generations, more than 50% of the explants were embryogenic.
Embryos at different stages of development were produced. Among cotyledonary-stage embryos, 50% had two cotyledons and a distinct
hypocotyl, 43% had one or more than 2 cotyledons and 7% had fused cotyledons. Most of the embryos were translucent and conversion
into plantlets was very rare. Secondary embryos could be observed to occur with low frequency from cultured somatic embryos
and from embryos emerging from calluses. Indirect somatic embryogenesis was also induced from immature zygotic embryos. From
one donor tree, 51% of the explants were embryogenic when cultured on a medium containing 0.9 μM kinetin, 0.9 μM BA and 0.5
μM NAA.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
19.
In an attempt to optimize somatic embryo formation in Oncidium ‘Gower Ramsey’, the effects of five auxins (2,4-D, IAA, IBA, NAA and picloram) and five cytokinins (2iP, BA, kinetin, TDZ
and zeatin), used alone, was tested in vitro using root-derived callus. In general, kinetin (0.5 and 2 mg l−1) and zeatin (0.5 mg l−1) were found to be more effective than other auxin and cytokinin treatments to induce somatic embryogenesis from root-derived
callus. 相似文献
20.
We elucidated the relationship between cell proliferation and somatic embryogenesis in the culture of carrot cotyledons. Fresh
weights of the cotyledon expiants were determined every five days while being cultured on a medium containing 2,4-D. Callus
production increased exponentially from Day 20 to Day 25, showing a two-fold rate of proliferation. To examine the embryogenic
potential of the callus, we pre-cultured cotyledon explants on an MS medium with 2,4-D, then transferred them to an MS basal
medium at five-day intervals. Somatic embryos formed most frequently when the cotyledons were pre-cultured for 20 days on
an MS medium that contained 5 μ2,4-D. The frequency of somatic embryo formation was 81%, while that of normal embryos with
two cotyledons was 51% among those formed on a hormone-free medium. We used FACScan analysis to relate the embryogenic potential
of the callus to the S phase in the cell cycle of cultured cells. The S phase was high after 25 days of culture on the medium
with 5 μM 2,4-D. In contrast, the frequency of normal embryogenesis was higher at Day 20 of the pre-culture period. Culturing
embryogenic calli on a medium with 5 μM 2,4-D was most favorable for producing somatic embryos with two cotyledons. We verified
that active somatic embryogenesis was apparently related to cell division activity; somatic embryos induced from actively
dividing cells were apt to accompany cotyledonary abnormality. 相似文献