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1.
Helena Mathews C. Schopke R. Carcamo P. Chavarriaga C. Fauquet R. N. Beachy 《Plant cell reports》1993,12(6):328-333
Methods for improving the efficiency of plant recovery from somatic embryos of cassava (Manihot esculenta Crantz) were investigated by optimizing the maturation regime and incorporating a desiccation stage prior to inducing germination. Somatic embryos were induced from young leaf lobes of in vitro grown shoots of cassava on Murashige and Skoog medium with 2,4-dichlorophenoxy acetic acid. After 15 to 20 days of culture on induction medium, the somatic embryos were transferred to a hormone free medium supplemented with activated charcoal. In another 18 days mature somatic embryos became distinctly bipolar and easily separable as individual units and were cultured on half MS medium for further development. Subsequent desiccation of bipolar somatic embryos resulted in 92% germination and 83% complete plant regeneration. The plants were characterized by synchronized development of shoot and root axes. Of the non-desiccated somatic embryos, only 10% germinated and 2% regenerated plants. Starting from leaf lobes, transplantable plantlets were derived from primary somatic embryos within 70 to 80 days.Abbreviations 2,4-D
2,4 dichlorophenoxyacetic acid
- BA
Benzyl aminopurine
- GA
Giberellic acid
- MS
Murashige and Skoog
- NAA
Naphthalene acetic acid 相似文献
2.
Kourosh Vahdati Shima Bayat Hassan Ebrahimzadeh Maryam Jariteh Masoud Mirmasoumi 《Plant Cell, Tissue and Organ Culture》2008,93(2):163-171
Low efficiency of embryo maturation, germination and conversion to plantlets is a major problem in many species including
Persian walnut. We studied the effects of abscisic acid (ABA) and sucrose, on the maturation and germination of Persian walnut
(Juglans regia) somatic embryos. Individual globular somatic embryos were grown on a maturation medium supplemented with different combinations
of ABA and sucrose for ca. 1 month, until shoot meristems and radicles had developed. White and opaque embryos in late cotyledonary
stage were subjected to desiccation after the culture period on maturation media. The number of germinated somatic embryos
was influenced by the concentrations of ABA in the maturation medium. The best treatment for germination, in which both shoot
and root were developed contained 2 mg l−1 ABA and resulted in 41% conversion of embryos into plantlets. Regeneration was reduced at higher levels of ABA. While ABA
always reduced the rate of secondary embryogenesis, treatments containing 4.0% sucrose significantly increased the number
of secondary embryos. On the other hand, sucrose had little influence on maturation. Normal and abnormal embryos were verified
anatomically. 相似文献
3.
Summary The influence of the zygotic seed coat on precocious germination and desiccation tolerance of somatic embryos has been studied using alfalfa (Medicago sativa L.). When cultured in contact with somatic embryos, seed coats at certain developmental stages inhibited precocious germination and induced desiccation tolerance in the somatic embryos. Germination of somatic embryos was inhibited by seed coats at the age of 16–26 days after pollination (DAP) and desiccation tolerance was induced after 20–26 DAP. Both phenomena were related to the synthesis of abscisic acid in the seed coat. The absence of a quiescent phase and desiccation tolerance in alfalfa somatic embryos may be related to the lack of developmental control by the seed coat.Abbreviations ABA
Abscisic acid
- DAP
Days after pollination 相似文献
4.
Regulation of Gene Expression in Developing Zea mays Embryos: Protein Synthesis during Embryogenesis and Early Germination of Maize 总被引:10,自引:5,他引:5 下载免费PDF全文
Polypeptides synthesized in dissected embryos of Zea mays at different stages of embryogenesis and early germination have been characterized by their migration in two-dimensional gel electrophoresis. This analysis has been carried out with in vivo labeled polypeptides from excised embryos and with proteins synthesized in vitro in the rabbit reticulocyte system directed by poly(A+) RNA isolated from the different developmental stages. We have identified three main sets of expressed polypeptides: (a) embryonic set: this group of polypeptides is synthesized in young and mature embryos but not in early germination; (b) maturation set: this group of polypeptides is not present in young embryos and appears during the maturation period. Some of these polypeptides are still present in early germination while others disappear from stored mRNAs in dry embryos. One particular group from this set can be induced prematurely in young embryos by incubation with abscisic acid; and (c) germination set: this group of polypeptides is not expressed in the maturation period and appears after brief imbibition of the dry embryos. 相似文献
5.
E. Sofiari C.J.J.M. Raemakers E. Kanju K. Danso A.M. van Lammeren E. Jacobsen R.G.F. Visser 《Plant Cell, Tissue and Organ Culture》1997,50(1):45-56
NAA and 2,4-D were compared for their ability to induce somatic embryogenesis in cassava (Manihot esculenta Crantz). In all seven cultivars tested, only 2,4-D had the capacity to induce primary somatic embryos from leaf explants,
however, both NAA and 2,4-D were capable of inducing secondary somatic embryos. More secondary somatic embryos were formed
in NAA than in 2,4-D medium. Furthermore, the maturation period for secondary somatic embryos was shorter in NAA medium than
in 2,4-D medium. In some cultivars, repeated subculture of secondary somatic embryos in NAA medium resulted in a gradual shift
from somatic embryogenesis to adventitious root formation. This shift could be stopped and reversed by subculture of the material
in 2,4-D medium. In NAA medium the most secondary somatic embryos were formed when they were subcultured every 15 days whereas
in 2,4-D a 20 day subculture interval was optimal. Subculture of secondary somatic embryos at a high inoculum density (>1.5
g jar−1) in NAA medium did not result in the formation of secondary somatic embryos, whereas in 2,4-D it lead to the formation of
globular secondary somatic embryos. With 2,4-D the newly induced secondary somatic embryos were connected vertically to the
explant and with NAA medium horizontally. For all cultivars tested, desiccation stimulated normal germination of NAA-induced
somatic embryos. However, the desiccated, secondary somatic embryos required a medium supplemented with BA for high frequency
germination. The concentration of BA needed for high frequency germination was higher when the desiccated secondary somatic
embryos were cultured in light instead of dark. In only one cultivar desiccation enhanced germination of 2,4-D induced secondary
somatic embryos and in three other cultivars it stimulated only root formation.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
6.
Onset of desiccation tolerance during development of the barley embryo 总被引:13,自引:0,他引:13
We have investigated events which take place in the developing barley (Hordeum vulgare L.) embryo during its acquisition of desiccation tolerance. Excised embryos are capable of precocious germination as early as 8 d after pollination (DAP). At this age, however, they are not capable of resisting a desiccation treatment which induces a loss of 96–98% of their initial water content. At 16 DAP the embryos germinate despite the drastic drying treatment. The pattern of in-vivo and in-vitro proteins synthesized by the developing embryos from 12 DAP (desiccation-intolerant) and 16 DAP (desiccation-tolerant) were compared. A set of 25–30 proteins was identified which is denovo synthesized or enhanced during the developmental period leading to desiccation tolerance. Abscisic acid (ABA; 100 M) applied in vitro for 5 d to 12-DAP embryos induces desiccation tolerance and represses a subset of polypeptides preferentially associated with 16-DAP embryos. During in vitro culture of barley embryos ABA stimulates the appearance of a set of proteins and prevents the precocious germination allowing embryogenesis to continue in vitro. It also suppresses a set of germination-related proteins which appear 4 h after the incubation of the dissected embryo on a germination medium without ABA. Almost all mRNAs remain functional for translation when isolated embryos are dried at the desiccation-intolerant and tolerant stages of embryo development.Abbreviations ABA
abscisic acid
- DAP
days after pollination
- GM
germination medium
- poly(A)RNA
polyadenylated RNA
- SDS
sodium dodecyl sulfate 相似文献
7.
Ravindra B. Malabadi K. Nataraja 《In vitro cellular & developmental biology. Plant》2006,42(2):152-159
Summary The present investigation reports optimized parameters for somatic embryogenesis and cryopreservation of embryogenic cultures
using shoot apical domes from mature trees of Pinus roxburghii Sarg. Embryogenic tissue of P. roxburghii Sarg. was cryopreserved for 24 h, 10 d, and 8 wk using sorbitol and dimethylsulfoxide (DMSO) as cryoprotectants. Results
indicate that 0.2M sorbitol and 5% DMSO had the best cryoprotecting effect. The recovered tissue showed luxuriant growth on maintenance medium
(II). Partial desiccation of thawed embryogenic tissue for 24 h prior to transfer to maturation medium enhanced the maturation
of somatic embryos. Maturation frequency increased from 1.3 to 18.3% after 12 h desiccation treatment, and from 18.3 to 61.8%
after 24 h of desiccation. However, non-desiccated embryogenic tissue produced the least number of somatic embryos (1.3%)
on the maturation medium with the same abscisic acid and Gellan gum concentration. All the three embryogenic lines produced
plantlets and had the same appearance and normal growth as compared to unfrozen controls. 相似文献
8.
A. Othmani C. Bayoudh N. Drira M. Marrakchi M. Trifi 《Plant Cell, Tissue and Organ Culture》2009,97(1):71-79
Plant regeneration through somatic embryogenesis from young leaf explants (5–10 mm long) adjacent to the apex of 5–6 year
old offshoots of Tunisian date palm (Phœnix dactylifera L.), cultivar Boufeggous was successfully achieved. Factors affecting embryogenic callus initiation, including plant growth
regulators and explant size, were investigated. The highest induction frequencies of embryogenic calli occurred after 6–7 months
on MS medium supplemented with 10 mg l−1 2,4-D and 0.3 mg l−1 activated charcoal. The subculture of these calli onto maintenance medium resulted in the formation of proembryos. Fine chopping
and partial desiccation (6 and 12 h) of embryogenic calli with proembryos prior to transfer to MS medium supplemented with
1 mg l−1 ABA stimulated the rapid maturation of somatic embryos. Maturated somatic embryo yield per 0.5 g FW of embryogenic callus
was 51 embryos with an average maturation time of 55 days. This was increased to 422 with finely chopped callus, and 124 and
306 embryos following 6 and 12 h desiccation treatments, respectively. The average time to maturation for these 3 treatments
was 35, 43 and 38 days, respectively. Subsequent substitution of ABA in MS medium with 1 mg l−1 NAA resulted in the germination and conversion of 81% of the somatic embryos into plantlets with normal roots and shoots.
The growth of regenerated somatic plants was also monitored in the field. 相似文献
9.
In order to enhance post-germinative vigour, somatic embryos of Picea glauca (Moench) Voss. were matured under in-vitro conditions that stimulated triacylglycerol (TAG) biosynthesis. In P. glauca seeds over 90% of the TAG was stored within the megagametophyte, and isolated zygotic embryos contained twice the amount of TAG of somatic embryos cultured for four weeks on basal medium containing 16 M abscisic acid (ABA). Polyethylene glycol-4000 (PEG) as a non-permeating osmoticum with ABA promoted TAG biosynthesis by somatic embryos and sustained maturation throughout an eight-week culture period. Treatments that promoted TAG biosynthesis also prevented precocious germination and promoted desiccation tolerance. Thus, the optimal culture conditions for maturation, desiccation survival, and plantlet regeneration were 16–24 M ABA and 7.5% PEG for eight weeks, followed by desiccation. Under these conditions the levels of TAG per somatic embryo were raised ninefold to about five times the zygotic-embryo level, and the TAG fatty-acid composition became similar to that of zygotic embryos. A study of sectioned material, using light and transmission electron microscopy, showed that the structure and distribution of lipid bodies within these somatic embryos and the degree of embryo development were similar to mature zygotic embryos. Up to 81% of the desiccated somatic embryos regenerated to plantlets during which time the TAG was utilised in a manner similar to zygotic seedlings.Abbreviations ABA
abscisic acid
- PEG
polyethylene glycol
- TAG
triacylglycerol
- TL
total lipid
- TEM
transmission electron microscopy
Plant Research Centre contribution No. 1383We are grateful to Dawn Moore and Ken Stanley for technical assistance, and thank Pat Rennie for the electron microscopy. We acknowledge financial support through an NSERC/Forestry Canada/Weyerhaeuser Canada Ltd (Prince Albert, Sask.) research partnership programme. 相似文献
10.
Kui Shin Voo Clayton L. Rugh Joe C. Kamalay 《In vitro cellular & developmental biology. Plant》1991,27(3):117-124
Summary We describe a tissue culture procedure for somatic embryogenesis and plantlet regeneration in cotton (Gossypium hirsutum L. cv. Coker 312). Callused explants or individual globular embryos were transferred to basal media to induce somatic embryogenesis.
To determine characteristic early indicators of successful germination and conversion, we identified six types of embryos
that developed on basal media. Two of the six embryo types, designated as tulip-shaped and trumpet-shaped, could undergo conversion
in preliminary tests, whereas the others had little or no developmental potential. Several media treatments designed to enhance
the maturation of globular somatic embryos failed to increase the fraction of embryos which matured to form recoverable types.
In efforts to improve plantlet recovery, tulip-shaped embryos were used in limited trials to contrast the effects of chemical
and physical desiccation treatments on germination and conversion. The selective use of tulip-shaped somatic embryos, coupled
with partial desiccation, seems to have augmented plant recovery. Growth habit, flowering, seed set, and lint production of
most of the regenerated plants were comparable to seed-derived plants grown under the same conditions.
Partial research support was provided by state and federal funds appropriated to the Ohio Agricultural Research and Development
Center, The Ohio State University. 相似文献
11.
12.
Vanda Šunderlíková Ján Salaj Dieter Kopecky Terézia Salaj Eva Wilhem Ildikó Matušíková 《Plant cell reports》2009,28(7):1011-1021
In this work, three dehydrin genes, QrDhn1, QrDhn2, QrDhn3, were isolated from recalcitrant oak (Quercus robur). Their expression pattern was analyzed in both zygotic and somatic embryos as well as in vegetative tissues exposed to different
kinds of abiotic stresses including desiccation, osmotic stress, and chilling. The QrDhn1 gene encoding for YnSKn type dehydrin was expressed during later stages of zygotic embryo development but in somatic embryos only when exposed to
osmotic or desiccation stress. In contrast, the other two oak dehydrin genes encoding for putative Kn type dehydrins were expressed only in somatic embryos (both not-treated and osmotically stressed) and leaves of oak seedlings
exposed to desiccation. Behavior of these genes suggests that different dehydrins are involved in processes of seed maturation
and response to altered osmotic (water status) conditions in somatic embryos. Revealing further members of dehydrin gene family
in recalcitrant oak might contribute to clarify non-orthodox seed behavior as well as identify mechanisms contributing to
desiccation tolerance in plants. 相似文献
13.
Improved somatic embryo maturation in loblolly pine by monitoring ABA-responsive gene expression 总被引:2,自引:0,他引:2
During loblolly pine zygotic embryo development, increases in mRNAs for three ABA-responsive LEA-like genes coincided with
the two developmental stage-specific peaks of endogenous ABA accumulation (Kapik et al. 1995). These ABA concentration profiles from zygotic embryo development were used to develop several tissue culture approaches
that altered the exposure of somatic embryos to exogenous ABA. Elevating exogenous ABA at a time corresponding to mid-maturation
improved the germination and resulted in more zygotic-like expression of selected genes in somatic embryos. Extending the
time on maturation medium for a fourth month increased embryo yield, dry weight, and germination in high-and low-yield genotypes.
Optimizing the amounts of embryogenic suspension, plated and exogenous ABA concentration increased from 22 to 66% in the early-stage
bipolar embryos that developed to the cotyledonary stage. 相似文献
14.
Mark L. Dahmer David F. Hildebrand Glenn B. Collins 《In vitro cellular & developmental biology. Plant》1992,28(2):106-114
Summary The relative maturity and competence of somatic embryos is often estimated on the basis of their morphologic similarity to
various stages of immature zygotic embryo development. Morphologic abnormalities noted in soybean [Glycine max (L.) Merr.] somatic embryos are similar to those observed in zygotic embryos maturing in vitro and may reflect common interruptions
of normal developmental processes. We provide here a more objective means of assessing the point(s) at which cultured embryos
deviate from the normal embryogenical pathway by comparing the accumulation of the embryo-specific marker proteins (11S and
7S storage globulins, soybean agglutinin, and seed lipoxygenase) between somatic and immature zygotic embryos maturing in
culture to zygotic embryos maturingin planta. Immature (heart-stage) soybean (cv. ‘McCall’) zygotic embryos were removed from the testa and cultured for 5, 15, or 45
days in nien modified Linsmaer-Skoog salts, 5% sucrose liquid medium. Somatic embryos were induced from immature cotyledon
explants on a medium containing either naphthalene acetic acid or 2,4 dichlorophenoxyacetic acid (10 mg·liter−1). The measured level of the marker proteins present in cultured embryos never exceeded those observed in mature soybean seeds.
During the culture period, immature zygotic embryos accumulated significant levels of all marker proteins except a 29 kDa
soybean agglutinin associated with the final stages of seed maturationin planta. Somatic embryos of all morphologic classes exhibited similar levels of the marker proteins suggesting that morphology may
not accurately represent the developmental state of the culture-derived embryos. Somatic embryos induced on naphthalene acetic
acid-containing medium accumulated detectable levels of all maturation-specific marker proteins except the 7S β and 29-kD
soybean agglutinin antigen and seemed similar in most respects to the cultured zygotic embryos. Embryos induced on 2,4-dichlorophenoxyacetic
acid accumulated none of the mature 7S or 11S storage globulin subunits nor any soybean agglutinin antigen, and yet the synthesis
of 7S and 11S precursor polypeptides was similar in both naphthalene acetic acid-and 2,4-dichlorophenoxyacetic acid-induced
somatic embryos. These observations are consistent with the view that embryos induced on high 2,4-dichlorophenoxyacetic are
arrested at a relatively earlier developmental stage than naphthalene acetic acid-induced embryos of similar morphology and
may indicate that some external signal (e.g., abscisic acid or desiccation or both) is necessary for the transition to the
late maturation stage of seed ontogeny. 相似文献
15.
Jean-Pierre Ele Ekouna Michèle Boitel-Conti Patrice Lerouge Muriel Bardor François Guerineau 《Plant Cell, Tissue and Organ Culture》2017,130(3):601-616
Somatic embryogenesis is a reliable and important tool, and the relevant genes controlling this process act as vital roles through the whole development of somatic embryos. However, regeneration via somatic embryogenesis in Chinese chestnut has been impeded and its molecular mechanism is not known. Therefore, firstly we described a protocol for somatic embryo initiation, development, maturation and germination. Embryogenic calli were obtained in embryo initiation medium containing 1.8 μM 2,4-D and 1.1 μM 6-BA, and then were transferred to embryo development medium without any hormones for at least 4 weeks, until cotyledonary embryos appeared. Next, the somatic embryos were transferred to embryo maturation medium containing Gamborg’s B-5 Basal Salt Mixture with 0.5 μM NAA and 0.5 μM 6-BA for 3 weeks. Finally, these mature embryos were germinated in embryo germination medium consisting of WPM with 0.5 μM NAA and 0.5 μM 6-BA, resulting in shoot regeneration with a 2.1% conversion rate. Additionally, eight embryogenesis-related genes were identified, and the expression profiles of these genes during embryogenesis were analyzed via quantitative real-time RT-PCR (qRT-PCR). The CmSERK, CmLEC1, CmWUS and CmAGL15 genes exhibited high expression in the initial embryo stages, which inferred that these genes played key roles during the initiation of embryogenesis. Studies on embryogenesis-related genes will provide an insight for further elucidating molecular mechanism during somatic embryogenesis of Chinese chestnut. Furthermore, the successful establishment of a somatic embryo regeneration system for Chinese chestnut will lay a significant foundation for a stable genetic transformation system and genetic improvement. 相似文献
16.
Agrobacterium-mediated transformation of American chestnut (Castanea dentata (Marsh.) Borkh.) somatic embryos 总被引:1,自引:0,他引:1
Linda D. Polin Haiying Liang Ronald E. Rothrock Mutsumi Nishii Deborah L. Diehl Andrew E. Newhouse C. Joseph Nairn William A. Powell Charles A. Maynard 《Plant Cell, Tissue and Organ Culture》2006,84(1):69-79
These studies were designed to test if a binary vector containing the gfp, bar and oxalate oxidase genes could transform American chestnut somatic embryos; to see if a desiccation treatment during co-cultivation would affect the transformation frequency of different American chestnut somatic embryo clones; to explore the effects of more rapid desiccation; and to see if the antibiotics used to kill the Agrobacterium were interfering with the regeneration of the somatic embryos. Two days of gradual desiccation was found to significantly enhance transient GFP expression frequency. When this treatment was tested on six American chestnut clones, five were transformed and four of these remained embryogenic. Transformation was confirmed by Southern hybridization. Phenotypically normal transgenic shoots were regenerated and rooted. Vascular tissue specific expression of the oxalate oxidase gene was detected in one transgenic line. Carbenicillin, cefotaxime, and tricarcillin were found to not interfere with the regeneration of transformed embryos. 相似文献
17.
Gene expression patterns were profiled during somatic embryogenesis in a regeneration-proficient maize hybrid line, Hi II, in an effort to identify genes that might be used as developmental markers or targets to optimize regeneration steps for recovering maize plants from tissue culture. Gene expression profiles were generated from embryogenic calli induced to undergo embryo maturation and germination. Over 1,000 genes in the 12,060 element arrays showed significant time variation during somatic embryo development. A substantial number of genes were downregulated during embryo maturation, largely histone and ribosomal protein genes, which may result from a slowdown in cell proliferation and growth during embryo maturation. The expression of these genes dramatically recovered at germination. Other genes up-regulated during embryo maturation included genes encoding hydrolytic enzymes (nucleases, glucosidases and proteases) and a few storage genes (an α-zein and caleosin), which are good candidates for developmental marker genes. Germination is accompanied by the up-regulation of a number of stress response and membrane transporter genes, and, as expected, greening is associated with the up-regulation of many genes encoding photosynthetic and chloroplast components. Thus, some, but not all genes typically associated with zygotic embryogenesis are significantly up or down-regulated during somatic embryogenesis in Hi II maize line regeneration. Although many genes varied in expression throughout somatic embryo development in this study, no statistically significant gene expression changes were detected between total embryogenic callus and callus enriched for transition stage somatic embryos.Supplementary material is available for this article at 相似文献
18.
Embryo development and germination of Cyclamen persicum have been comparatively characterized for zygotic and somatic embryos with regard to mitotic activity and morphology in order to identify developmental abnormalities in somatic embryogenesis. Zygotic embryo development proved to be highly synchronous with distinct periods of cell division, cell elongation and embryo maturation within a total period of 17 weeks of seed development. Somatic embryo development was accomplished within only 3 weeks, resulting in a mixture of morphologically highly variable embryos. No distinct developmental periods could be identified and no reduction of the mitotic activity was discovered for non-desiccated somatic embryos. Controlled desiccation of somatic embryos severely reduced their germination rate, demonstrating resemblance of somatic embryos to recalcitrant seeds, whereas zygotic Cyclamen seeds could be characterized as typically orthodox. 相似文献
19.
Effect of Abscisic Acid, Osmoticum, and Desiccation on Synthesis of Storage Proteins during the Development of White Spruce Somatic Embryos 总被引:10,自引:0,他引:10
The effect of abscisic acid (ABA), non-permeating osmoticumand desiccation treatment on storage protein synthesis duringmaturation of somatic embryos of Picea glauca (Moench) Voss.was examined. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis(SDS-PAGE) and Western blot analysis demonstrated that someof the major crystalloid and matrix polypeptides were absentfrom somatic embryos maturing on medium containing ABA and lowosmoticum. However, treatment with polyethylene glycol-4000(PEG) in combination with ABA resulted in the synthesis of aspectrum of storage polypeptides resembling that of mature zygoticembryos. These storage proteins accumulated throughout an 8-weekculture period, resulting in a threefold higher protein contentthan somatic embryos maturing for the same time in the absenceof PEG. The structure and distribution of protein bodies incells of these osmotically treated somatic embryos was similarto that in cells of mature zygotic embryos. Treatment with 5·0-7·5%PEG prevented catabolism of the accumulated storage polypeptidesduring desiccation. The optimal culture conditions for somaticembryo maturation and storage protein deposition was 16 µMABA and 7·5% PEG for 8 weeks followed by desiccation.Analysis of mRNAs by in vitro translation and immunoprecipitationof translated products showed that the crystalloid protein mRNAprofiles of zygotic and those of somatic embryos maturing on16 µM ABA in the absence of PEG were similar. The differencesobserved in the pattern of accumulated polypeptides in thesesomatic embryos and those of mature zygotic embryos, therefore,indicates that storage-protein synthesis in response to osmoticumis in part regulated at the translational level. During regenerationof somatic embryos to plantlets the storage polypeptides wererapidly utilized in a manner similar to that in zygotic seedlings.Copyright1993, 1999 Academic Press Desiccation, osmotic stress, storage proteins, Picea, embryogenesissomatic, mRNA (crystalloid protein) 相似文献
20.
M. A. Lelu K. Klimaszewska G. Pflaum C. Bastien 《In vitro cellular & developmental biology. Plant》1995,31(1):15-20
Summary Cotyledonary somatic embryos ofLarix × leptoeuropaea that developed after various maturation times on media containing abscisic acid showed different frequencies of conversion
into plants. Drying of these somatic embryos under high relative humidity (RH) before germination improved plantlet recovery
and eliminated differences in the performance of somatic embryos matured for different times. However, dehydration of somatic
embryos under 98% RH to a water content below that of zygotic embryos excised from mature seeds (0.97 and 1.36 g H2O/g dry weight, respectively) showed a strong positive correlation between longer maturation time and desiccation tolerance.
Drying somatic embryos at 4° C under 59% RH for 1 wk resulted in desiccation to a water content of 0.30 g H2O/g dry weight, which was the closest to the hydration state of zygotic embryos in dried, stored seeds (0.20 g H2O/g dry weight). Under this condition, only somatic embryos matured for 5 wk germinated and produced plantlets at a relatively
high frequency (73 and 41%, respectively). 相似文献