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1.
We examined changes in the absence versus presence patterns of phosphoproteins with respect to the acquisition of embryogenic
competence during somatic embryogenensis in carrot (Daucus carota L.). To characterize a possible correlation between the induction of embryogenic competence and protein phosphorylation,
we examined the patterns of protein phosphorylation in embryogenic cells (EC) and non-embryogenic cells (NC) that had lost
the ability to form somatic embryos. Two-dimensional polyacrylamide gel electrophoresis and subsequent autoradiography revealed
the presence of 31 phosphoproteins in EC but not in NC. Furthermore, when we examined the induction of somatic embryogenesis
by certain stress compounds in the absence of phytohormones, we identified one specific phosphoprotein (ECPP-44). ECPP-44
was found to be induced in all treatments that resulted in embryogenic competence. The partial amino acid and nucleotide sequence
of ECPP-44 shows partial homology to two dehydrins (ERD10 and ERD14) from Arabidopsis.
Received: 1 October 1999 · Accepted: 3 November 1999 相似文献
2.
Somatic embryogenesis induced by the simple application of abscisic acid to carrot (Daucus carota L.) seedlings in culture 总被引:3,自引:0,他引:3
Seedlings of carrot (Daucus carota L. cv. Red Cored Chantenay) formed somatic embryos when cultured on medium containing abscisic acid (ABA) as the sole source
of growth regulator. The number of embryos per number of seedlings changed depending on the concentration of ABA added to
the medium, with a maximum embryo number at 1 × 10−4 M ABA. Seedling age was critical for response to exogenous ABA; no seedling with a hypocotyl longer than 3.0 cm was able to
form an embryo. Removal of shoot apices from seedlings completely inhibited the embryogenesis induced by application of exogenous
ABA, suggesting that the action of ABA requires some substance(s) that is translocated basipetally from shoot apices through
hypocotyls. Histologically, somatic embryos shared common epidermal cells and differentiated not through the formation of
embryogenic cell clumps, but directly from epidermal cells. These morphological traits are distinct from those of embryogenesis
via formation of embryogenic cell clumps, which has been found in embryogenic carrot cultures established using 2,4-dichlorophenoxyacetic
acid or other auxins. These results suggest that ABA acts as a signal substance in stress-induced carrot seedling somatic
embryogenesis.
Received: 22 April 2000 / Accepted: 8 June 2000 相似文献
3.
IAA Metabolism in Embryogenic and Non-Embryogenic Carrot Cells 总被引:1,自引:0,他引:1
Sasaki Kazuo; Shimomura Koichiro; Kamada Hiroshi; Harada Hiroshi 《Plant & cell physiology》1994,35(8):1159-1164
Carrot somatic embryos can readily be induced from embryogeniccells transferred from auxin-containing medium to auxin-freemedium, but not from transferred non-embryogenic cells. It iswell-known that IAA, a natural auxin, plays important rolesin many physiological responses including somatic embryogenesis,but, there is no report of the IAA metabolism in embryogenicand non-embryogenic cells. Therefore, we examined IAA metabolismin embryogenic and nonembryogenic carrot cells. In this paper the IAA metabolism in embryogenic cells and non-embryogeniccells is described. The induction of IAAsp formation was clarifiedin both cells. On the other hand, in non-embryogenic cells,an unknown metabolite was detected and identified as oxindole-3-acetylasparticacid (oxIAAsp). OxIAAsp formation may be induced to eliminateexcess auxin. Furthermore, endogenous IAA contents in both cellswere quantified and the relationship between somatic embryogenesisand IAA metabolism is discussed. (Received May 2, 1994; Accepted August 30, 1994) 相似文献
4.
Kiyosue Tomohiro; Dong Jian Guo; Satoh Shinobu; Kamada Hiroshi; Harada Hiroshi 《Plant & cell physiology》1990,31(7):947-950
Monoclonal antibodies were raised against proteins in a microsomalfraction from carrot embryogenic cells. The presence of a 31-kDaembryogenic cell antigen detected by one antibody (ID 11) wasdemonstrated in embryogenic cells but not in other plant materials,such as non-embryogenic cells, somatic embryos, crown gallsand hairy roots. The antigen was also present in organ segmentsthat carried somatic embryos having been induced by exposureto various stresses. In non-embryogenic cells, the antibodyrecognized a small amount of a 32-kDa antigen. Both the 31-and the 32-kDa antigens accumulated in carrot seeds during theirdevelopment and then disappeared after germination. (Received April 16, 1990; Accepted July 16, 1990) 相似文献
5.
Somatic embryogenesis from pea embryos and shoot apices 总被引:3,自引:0,他引:3
Conditions were defined for plant regeneration via somatic embryogenesis in pea, using explants from immature zygotic embryos or from shoot apices. For the induction of somatic embryos, an auxin (picloram or 2,4-dichlorophenoxyacetic acid) was required. Embryogenic callus originated from embryonic axis tissue of immature embryos and from the axillary-bud region and the plumula of shoot apices. A clear effect of embryo size on somatic embryogenesis was shown. There were differences in frequency of somatic embryogenesis among the five genotypes used in the study. Additions of BA to auxin-containing medium reduced embryo production. Histological examinations confirmed the embryogenic nature of the immature embryo cultures and revealed that somatic embryos originated from the meristematic areas near the callus surface.Abbreviations BA
benzyladenine
- 2,4-D
2,4-dichlorophenoxyacetic acid
- NAA
naphthaleneacetic acid
- picloram
4-amino-3,5,6-trichloropicolinic acid 相似文献
6.
Hajime Shiota Sukmin Ko Shinko Wada Claudia Tomiko Otsu Ichiro Tanaka Hiroshi Kamada 《Plant Physiology and Biochemistry》2008,46(5-6):550-558
Carrot (Daucus carota) somatic embryogenesis has been extensively used as an experimental system for studying embryogenesis. In maturing zygotic embryos, abscisic acid (ABA) is involved in acquisition of desiccation tolerance and dormancy. On the other hand, somatic embryos contain low levels of endogenous ABA and show desiccation intolerance and lack dormancy, but tolerance and dormancy can be induced by exogenous application of ABA. In ABA-treated carrot embryos, some ABA-inducible genes are expressed. We isolated the Daucus carota bZIP1 (DcBZ1) gene encoding a G-box binding factor-type basic region/leucine zipper (GBF-type bZIP) factor from carrot somatic embryos. The expression of DcBZ1 was detected in embryogenic cells, non-embryogenic cells, somatic embryos, developing seeds, seedlings, and true leaves. Notably, higher expression was detected in embryogenic cells, true leaves, and seedlings. The expression of DcBZ1 increased in seedlings and true leaves after ABA treatment, whereas expression was not affected by differences in light conditions. During the development of zygotic and somatic embryos, increased expression of DcBZ1 was commonly detected in the later phase of development. The recombinant DcBZ1 protein showed specific binding activity to the two ABA-responsive element-like motifs (motif X and motif Y) in the promoter region of the carrot ABA-inducible gene according to results from an electrophoretic mobility shift assay. Our findings suggest that the carrot GBF-type bZIP factor, DcBZ1, is involved in ABA signal transduction in embryogenesis and other vegetative tissues. 相似文献
7.
Summary Somatic embryogenesis from different genotypes of Asparagus officinalis L. could be obtained by in vitro culture of shoot apices. Apices were first cultured on an auxin-rich inducing medium and then transferred onto a hormone-free development medium. All genotypes tested in this way produced a few somatic embryos. In some experiments, during the development phase, a new kind of friable highly embryogenic tissue appeared in a random manner. These tissues could be continuously subcultured on a hormone-free medium and were named embryogenic lines. Five of these embryogenic lines regenerated plants from somatic embryos. These regenerated plants exhibited an increased embryogenic response compared to the parent plants; e.g. apex culture produced somatic embryos without any auxin treatments. For one of the embryogenic lines, a genetic analysis showed that the improved embryogenic response of regenerated plants was controlled by a mendelian dominant monogenic mutation.Abbreviations LSEA
low somatic embryogenesis ability
- HSEA
high somatic embryogenesis ability
- NAA
1-naphthaleneacetic acid 相似文献
8.
Somatic embryogenesis in carrot ( Daucus carota L.) is strongly inhibited by certain factors that accumulate in culture medium of high-density cultures of embryogenic cells. We previously identified 4-hydroxybenzyl alcohol (4HBA) as one of the inhibitory factors. In this study, we analyzed the accumulation pattern of 4HBA in the cultures of carrot suspension cells. When somatic embryogenesis was induced by culturing embryogenic cells in phytohormone-free Murashige and Skoog medium at various initial cell densities, 4HBA accumulated in the culture medium. The concentration of 4HBA in high cell density cultures was higher than in low cell density cultures. The accumulation of 4HBA in high cell density cultures was rapid during the early days of culture. This rapid accumulation of 4HBA in high cell density cultures might result in the strong inhibition of somatic embryogenesis. The production of 4HBA decreased as the somatic embryos developed. In addition, embryogenic cells released larger amount of 4HBA into the culture medium compared with non-embryogenic cells. These results suggest that the production of 4HBA is both related to embryogenic competence and developmentally regulated during somatic embryogenesis. 相似文献
9.
Yamamoto N Kobayashi H Togashi T Mori Y Kikuchi K Kuriyama K Tokuji Y 《Journal of plant physiology》2005,162(1):2493-54
Using a direct somatic embryogenesis system in carrot, we examined the role of DNA methylation in the change of cellular differentiation state, from somatic to embryogenic. 5-Azacytidine (aza-C), an inhibitor of DNA methylation suppressed the formation of embryogenic cell clumps from epidermal carrot cells. Aza-C also downregulated the expression of DcLEC1c, a LEC1-like embryonic gene in carrot, during morphogenesis of embryos. A carrot DNA methyltransferase gene, Met1-5 was expressed transiently after the induction of somatic embryogenesis by 2,4-dichlorophenoxyacetic acid (2,4-D), before the formation of embryogenic cell clumps. These findings suggested the significance of DNA methylation in acquiring the embryogenic competence in somatic cells in carrot. 相似文献
10.
K Sankara Rao 《Journal of biosciences》1996,21(6):827-841
The overall architectural pattern of the mature plant is established during embryogenesis. Very little is known about the
molecular processes that underlie embryo morphogenesis. Last decade has, nevertheless, seen a burst of information on the
subject. The synchronous somatic embryogenesis system of carrot is largely being used as the experimental system. Information
on the molecular regulation of embryogenesis obtained with carrot somatic embryos as well as observations on sandalwood embryogenic
system developed in our laboratory are summarized in this review. The basic experimental strategy of molecular analysis mostly
relied on a comparison between genes and proteins being expressed in embryogenic and non-embryogenic cells as well as in the
different stages of embryogenesis. Events such as expression of totipotency of cells and establishment of polarity which are
so critical for embryo development have been characterized using the strategy. Several genes have been identified and cloned
from the carrot system. These include sequences that encode certain extracellular proteins (EPs) that influence cell proliferation
and embryogenesis in specific ways and sequences of the abscisic acid (ABA) inducible late embryogenesis abundant (LEA) proteins
which are most abundant and differentially expressed mRNAs in somatic embryos. That LEAs are expressed in the somatic embryos
of a tree flora also is evidenced from studies on sandalwood. Several undescribed or novel sequences that are enhanced in
embryos were identified. A sequence of this nature exists in sandalwood embryos was demonstrated using aCuscuta haustorial (organ-specific) cDNA probe. Somatic embryogenesis systems have been used to assess the expression of genes isolated
from non-embryogenic tissues. Particular attention has been focused on both cell cycle and histone genes 相似文献
11.
Possible involvement of abscisic acid in the induction of secondary somatic embryogenesis on seed-coat-derived carrot somatic embryos 总被引:1,自引:0,他引:1
When seed coats (pericarps) were picked from 14-day-old carrot (Daucus carota) seedlings and cultured on agar plates, embryogenic cell clusters were produced very rapidly at a high frequency on the open side edge. Embryo induction progressed without auxin treatment; indeed treatment caused the formation of non-embryogenic callus. The embryogenic tissues (primary embryos) developed normally until the torpedo stage; however, after this a number of secondary somatic embryos were produced in the hypocotyl and root regions. Tertiary embryos were formed on some of the secondary embryos, but many developed into normal plantlets. The primary embryos contained significantly higher levels of abscisic acid (ABA) than the hypocotyl-derived normal and seed-coat-derived secondary embryos. Fluridone inhibited the induction of secondary embryogenesis, while exogenously supplied ABA induced not only tertiary embryogenesis on the seed-coat-derived secondary embryos, but also secondary embryos on the hypocotyl-derived normal somatic embryos. These results indicate that ABA is one of the important endogenous factors for the induction of secondary embryogenesis on carrot somatic embryos. Higher levels of indole-3-acetic acid (IAA) in primary embryos also suggest the presence of some concerted effect of ABA and IAA on the induction of secondary embryogenesis in primary embryos. 相似文献
12.
A carrot cell culture line was shown to be highly embryogenic, but plantlet recovery (conversion) was low (about 14%). The majority of somatic embryos that did not convert showed pronounced vacuolation in the apical notch, leading to their inability to form primary leaves and thereby convert. Comparisons of developing meristems in the shoot apical notch of converting somatic and zygotic embryos revealed similarities in cytoplasmic density and meristem organization between the two populations. Abscisic acid (ABA) was shown to significantly increase conversion in somatic embryos of globular, torpedo, and preplantlet stages (62%, 62.5% and 40%, respectively). Somatic embryos that were treated with 50 μM ABA showed retention of the highly cytoplasmic cells in the apical notch. Histological analysis showed a resemblance between shoot apices of converting somatic embryos and ABA-treated somatic embryos. ABA may be an induction agent for meristematic organization, or perhaps may cause cells of the apical notch to extend competence for determination as meristematic cells. 相似文献
13.
M. Griga 《Biologia Plantarum》2002,45(2):173-182
The morphological and anatomical aspects of direct and indirect somatic embryogenesis in pea were described. Direct embryos were induced from shoot apical meristems of 3 to 5-d-old pea seedlings, embryogenic callus originated from immature pea zygotic embryos or shoot apices. Auxin (picloram, 2,4-dichlorophenoxyacetic acid) was necessary to induce somatic embryos. The developmental stages typical for pea zygotic embryos were detected. Globular and heartshaped somatic embryos were morphologically similar to their zygotic counterparts; in contrast, torpedo and cotyledonary somatic embryos displayed great morphological variation, which affected mainly cotyledons (size, shape, number). Based on anatomical sections, possible ways of somatic embryo formation and localization of initiation sites within primary explant tissue have been proposed. The multicellular origin of somatic embryos is supposed in both systems of pea somatic embryogenesis under investigation. 相似文献
14.
Spindles of CUBA 87-51 sugarcane were cultured in Murashige and Skoog (MS) basal medium and supplemented with different nutrients. Embryogenic and non-embryogenic callus obtained were comparatively studied by scanning electron microscopy (SEM). Samples of embryogenic callus cultured in regeneration medium (MS without 2.4 dichlorophenoxyacetic acid) were taken at different times for analyzing the sequential process. Distinctive features of two types of callus are shown by SEM: cells organized in embryos are noted in embryogenic callus; while elongated, disorganized cells can be seen in non-embryogenic callus. The characteristics of the embryos during plant regeneration are described. Sugarcane embryoid stages are: globular, globular with lateral notch and scutellum. In this process also appear shoot meristems, leaf and root primordia and finally, true leaves and roots. It is concluded that callus plant regeneration from young leaf segments of sugarcane mainly occur via somatic embryogenesis. 相似文献
15.
Lambé Pascal Mutambel Hity S.N. Deltour Roger Dinant Monique 《Plant Cell, Tissue and Organ Culture》1998,55(1):23-29
Three genotypes of Pearl millet were screened in vitro for induction of embryogenic callus, somatic embryogenesis and regeneration.
Shoot apices excised from in vitro germinated seedlings or immature embryos isolated from green house established plants were
used as primary explants. The frequency of embryogenic callus initiation was significantly higher in shoot apices in comparison
with immature zygotic embryos. Moreover, differences between genotypes were minimal when using shoot apices. Friable embryogenic
calli (type II) developed on the initial nodular calli after 1 to 3 months of culture. The frequency of type II callus is
related to the composition of the maintenance medium and they were more often found in ageing cultures. The transfer of embryogenic
calli onto auxin-free medium was sufficient for inducing somatic embryo development in short-term culture (3 months) while
a progressive loss in regeneration potential was observed with increasing time of subcultures. Maturation of embryogenic calli
on medium supplemented with activated charcoal, followed by germination of somatic embryos on medium supplemented with gibberellic
acid, restored regeneration in long-term cultures.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
16.
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18.
Sacco C. de Vries Hilbert Booij Peter Meyerink Gert Huisman H. Dayton Wilde Terry L. Thomas Ab van Kammen 《Planta》1988,176(2):196-204
Embryogenic suspension cultures of domesticated carrot (Daucus carota L.) are characterized by the presence of proembryogenic masses (PEMs) from which somatic embryos develop under conditions of low cell density in the absence of phytohormones. A culture system, referred to as starting cultures, was developed that allowed analysis of the emergence of PEMs in newly initiated hypocotyl-derived suspension cultures. Embryogenic potential, reflected by the number of FEMs present, slowly increased in starting cultures over a period of six weeks. Addition of excreted, high-molecular-weight, heat-labile cell factors from an established embryogenic culture considerably accelerated the acquisition of embryogenic potential in starting cultures. Analysis of [35S]methionine-labeled proteins excreted into the medium revealed distinct changes concomitant with the acquisition of embryogenic potential in these cultures. Analysis of the pattern of gene expression by in-vitro translation of total cellular mRNA from starting cultures with different embryogenic potential and subsequent separation of the [35S]methionine-labeled products by two-dimensional polyacrylamide gel electrophoresis demonstrated a small number of abundant in-vitro-translation products to be present in somatic embryos and in embryogenic cells but absent in nonembryogenic cells. Several other in-vitro-translation products were present in explants, non-embryogenic and embryogenic cells but were absent in somatic embryos. Hybridization of an embryoregulated complementary-DNA sequence, Dc3, to RNA extracted from starting cultures showed that the corresponding gene is expressed in somatic embryos and PEMs but not in non-embryogenic cells.Abbreviations 2,4-D
2,4-dichlorophenoxyacetic acid
- cDNA
complementary DNA
- PAGE
polyacrylamide gel electrophoresis
- PEM
proembryogenic mass 相似文献
19.
Abscisic acid and stress treatment are essential for the acquisition of embryogenic competence by carrot somatic cells 总被引:5,自引:0,他引:5
Studies of carrot embryogenesis have suggested that abscisic acid (ABA) is involved in somatic embryogenesis. A relationship between endogenous ABA and the induction of somatic embryogenesis was demonstrated using stress-induced system of somatic embryos. The embryonic-specific genes C-ABI3 and embryogenic cell proteins (ECPs) were expressed during stress treatment prior to the formation of somatic embryos. The stress-induction system for embryogenesis was clearly distinguished by two phases: the acquisition of embryogenic competence and the formation of a somatic embryo. Somatic embryo formation was inhibited by the application of fluridone (especially at 10−4 M), a potent inhibitor of ABA biosynthesis, during stress treatment. The inhibitory effect of fluridone was nullified by the simultaneous application of fluridone and ABA. The level of endogenous ABA increased transiently during stress. However, somatic embryogenesis was not significantly induced by the application of only ABA to the endogenous level, in the absence of stress. These results suggest that the induction of somatic embryogenesis, in particular the acquisition of embryogenic competence, is caused not only by the presence of ABA but also by physiological responses that are directly controlled by stresses. 相似文献
20.
Gorpenchenko TY Kiselev KV Bulgakov VP Tchernoded GK Bragina EA Khodakovskaya MV Koren OG Batygina TB Zhuravlev YN 《Planta》2006,223(3):457-467
Expression of the Agrobacterium rhizogenes rolC gene in Panax ginseng callus cells results in formation of tumors that are capable to form roots. The selection of non-root forming tumor clusters
yielded the embryogenic 2c3 callus line, which formed somatic embryos and shoots independently of external growth factors.
Although the 2c3 somatic embryos developed through a typical embryogenesis process, they terminated prematurely and repeatedly
formed adventitious shoot meristems and embryo-like structures. A part of the shoots and somatic embryos formed enlarged and
fasciated meristems. This is the first indication of the rolC gene embryogenic effect and, to our knowledge, the first indication that a single gene of non-plant origin can induce somatic
embryogenesis in plants. 相似文献