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131.
Chen Yurong Kenaschuk Edward Dribnenki Paul 《Plant Cell, Tissue and Organ Culture》1999,57(3):195-198
Forty-four flax genotypes with a diverse genetic background were evaluated for anther culture response using a standard anther
culture protocol in order to determine the feasibility to initiate a routine haploid production system in applied breeding
programs. A strong genotype effect on callus induction and shoot regeneration in anther culture was found in this study. A
number of genotypes, including two low cadmium content lines 96-11785 and 96-11826, a high oil content line 96-22109 and a
high linolenic acid content line M 4919 were identified as highly responsive. The impact of the findings in this study on
flax breeding was discussed.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
132.
Magdalena Wróbel‐Kwiatkowska Katarzyna Skórkowska‐Telichowska Lucyna Dymińska Mirosław Mączka Jerzy Hanuza Jan Szopa 《Biotechnology progress》2009,25(5):1489-1498
The interest in biofibers has grown in recent years due to their expanding range of applications in fields as diverse as biomedical science and the automotive industry. Their low production costs, biodegradability, physical properties, and perceived eco‐friendliness allow for their extensive use as composite components, a role in which they could replace petroleum‐based synthetic polymers. We performed biochemical, mechanical, and structural analyses of flax stems and fibers derived from field‐grown transgenic flax enriched with PHB (poly‐β‐hydroxybutyrate). The analyses of the plant stems revealed an increase in the cellulose content and a decrease in the lignin and pectin contents relative to the control plants. However, the contents of the fibers' major components (cellulose, lignin, pectin) remain unchanged. An FT‐IR study confirmed the results of the biochemical analyses of the flax fibers. However, the arrangement of the cellulose polymer in the transgenic fibers differed from that in the control, and a significant increase in the number of hydrogen bonds was detected. The mechanical properties of the transgenic flax stems were significantly improved, reflecting the cellulose content increase. However, the mechanical properties of the fibers did not change in comparison with the control, with the exception of the fibers from transgenic line M13. The generated transgenic flax plants, which produce both components of the flax/PHB composites (i.e., fibers and thermoplastic matrix in the same plant organ) are a source of an attractive and ecologically safe material for industry and medicine. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 相似文献
133.
Functional diversity in arbuscular mycorrhizas: exploitation of soil patches with different phosphate enrichment differs among fungal species 总被引:3,自引:1,他引:3
Most terrestrial plant species form associations with arbuscular mycorrhizal fungi (AMF) that transfer soil P to the plant via their external hyphae. The distribution of nutrients in soils is typically patchy (heterogeneous) but little is known about the ability of AMF to exploit P patches in soil. This was studied by growing symbioses of Linum usitatissimum and three AMF (Glomus intraradices, G. mosseae and Gigaspora margarita) in pots with two side-arms, which were accessible to hyphae, but not to roots. Soil in one side-arm was either unamended (P0) or enriched with P; simultaneous labelling of this soil with 32P revealed that G. intraradices responded to P enrichment both in terms of hyphal proliferation and P uptake, whereas the other AMF did not. Labelling with 33P of P0 soil in the other side arm revealed that the increased P uptake by G. intraradices from the P-enriched patch was paralleled by decreased P uptake by other parts of the mycelium. This is the first demonstration of variation in growth and nutrient uptake by an AMF as influenced by a localized P enrichment of the soil. The results are discussed in the context of functional diversity of AMF. 相似文献
134.
Distyly inLinum tenuifolium L. is associated with a high degree of self-incompatibility. Breakdown in this system has occurred without the morphological rearrangement expected as the result of cross-over within the distyly supergene. Pollen-flow in both distylous and monomorphic populations is leptokurtic. A high proportion of intra-flower pollination occurs. Pollen production per ovule is reduced in the self-compatible race. Mean seed-set is increased. Individuals of the self-compatible race produce less vegetative growth and require a shorter time to reach reproductive maturity under cultivation. Increased fecundity appears to provide the selective advantage promoting the breakdown of self-incompatibility in this species. This is achieved through a massive shift of resources toward female reproductive function in plants of the monomorphic race. Subsequent colonization by this race has led to its increased distribution in C. & S. Europe. 相似文献
135.
Wim Van Uden Aart S. Bouma Jan F. Bracht Waker Oskar Middel Harry J. Wichers Pieter De Waard Herman J. Woerdenbag Richard M. Kellogg Niesko Pras 《Plant Cell, Tissue and Organ Culture》1995,42(1):73-79
The bioconversion of the lignan desoxypodophyllotoxin by cell suspensions of Linum flavum and of Podophyllum hexandrum was investigated. The apolar substrate could be easily dissolved in the culture medium at a concentration of 2 mM by complexation with dimethyl--cyclodextrin. Growth parameters of the cell suspensions were not affected by either the addition of cyclodextrin itself, or when cyclodextrin-complexed desoxypodophyllotoxin was present in the medium. The complexed lignan disappeared from the medium within 7 days for both cell cultures. Cellularly only small amounts of desoxypodophyllotoxin were found. After feeding of desoxypodophyllotoxin, the cell culture of L. flavum accumulated 5-methoxypodophyllotoxin and 5-methoxypodophyllotoxin--D-glucoside. After 7 days a total maximal content of 2.38% on a dry weight basis of 5-methoxypodophyllotoxin was formed, corresponding with 249 mg l-1 suspension. The highest bioconversion percentage of 52.3% was found at day 14. The desoxypodophyllotoxin-fed culture of P. hexandrum accumulated podophyllotoxin and its -D-glucoside with a maximal content of 2.87% on a dry weight basis after 9 days, corresponding with 192 mg 1-1 suspension. The highest bioconversion percentage of 33.2% was also found at day 9. 相似文献
136.
137.
Bérénice Bretagne Marie-Christine Chupeau Yves Chupeau Guy Fouilloux 《Plant cell reports》1994,14(2-3):120-124
Summary The effects of thidiazuron, benzyladenine and zeatin were tested with respect to bud regeneration of different flax explants from hypocotyls, cotyledons and apices of two fibre varieties (Ariane, Viking) and one linseed variety (Antarès). These three cytokinins were tested either alone or in combination with naphthalene acetic acid, indole acetic acid or 2,4-dichlorophenoxyacetic acid.Hypocotyls were the most responsive explants. Thidiazuron was significantly the most effective followed by benzyladenine, and then zeatin, in inducing organogenesis from hypocotyl segments. The optimal thidiazuron concentration for bud regeneration from hypocotyls was 0.1–0.3 M in combination with 0.01 M of naphthalene acetic acid. Six days after plating, shoot initials began to appear on hypocotyl sections compared with ten to fifteen days when using benzyladenine or zeatin. 相似文献
138.
Flax (Linum usitatissimum L.) is a raw material used for important industrial products. Linen has very high quality textile properties, such as its strength,
water absorption, comfort and feel. However, it occupies less than 1% of the total textile market. The major reason for this
is the long and difficult retting process by which linen fibres are obtained. In retting, bast fibre bundles are separated
from the core, the epidermis and the cuticle. This is accomplished by the cleavage of pectins and hemicellulose in the flax
cell wall, a process mainly carried out by plant pathogens like filamentous fungi. The remaining bast fibres are mainly composed
of cellulose and lignin. The aim of this study was to generate plants that could be retted more efficiently. To accomplish
this, we employed the novel approach of transgenic flax plant generation with increased polygalacturonase (PGI ) and rhamnogalacturonase
(RHA) activities. The constitutive expression of Aspergillus aculeatus genes resulted in a significant reduction in the pectin content in tissue-cultured and field-grown plants. This pectin content
reduction was accompanied by a significantly higher (more than 2-fold) retting efficiency of the transgenic plant fibres as
measured by a modified Fried’s test. No alteration in the lignin or cellulose content was observed in the transgenic plants
relative to the control. This indicates that the over-expression of the two enzymes does not affect flax fibre composition.
The growth rate and soluble sugar and starch contents were in the range of the control levels. It is interesting to note that
the RHA and PGI plants showed higher resistance to Fusarium culmorum and F. oxysporum attack, which correlates with the increased phenolic acid level. In this report, we demonstrate for the first time that over-expression
of the A. aculeatus genes results in flax plants more readily usable for fibre production. The biochemical parameters of the cell wall components
indicated that the fibre quality remains similar to that of wild-type plants, which is an important pre-requisite for industrial
applications.
Magdalena Musialak and Magdalena Wróbel-Kwiatkowska participated equally in the preparation of this paper 相似文献
139.
A set of 28 fibre flax and linseed cultivars differing in plant morphology and technological parameters were analysed by isozyme markers in five ontogenetic phases. Relatively high isozyme polymorphism was observed using polyacrylamide gel electrophoresis. Altogether 18 isozyme systems produced 145 different bands; 66 of them (45.52 %) have been found to be polymorphic. The highest level of polymorphism was found in acid phosphatase and esterase, polymorphism was detected in aconitase, diaphorase, glutamate dehydrogenase, peroxidase and superoxide dismutase as well. The highest number of unique isozymic spectra (cultivar × enzyme × ontogenetic phase) was detected in the phase of shoot with removed cotyledons. Electrophoretic analysis of all polymorphic isozymes enabled to distinguish 20 cultivars (71 %) in the screened cultivar set. 相似文献
140.
S-Adenosyl-L-methionine:beta-peltatin 6-O-methyltransferase was isolated and characterized from cell suspension cultures of Linum nodiflorum L. (Linaceae), a Linum species accumulating aryltetralin lignans such as 6-methoxypodophyllotoxin. The enzyme transfers a methyl group from S-adenosyl-L-methionine to the only free OH-group of beta-peltatin in position 6 thus forming beta-peltatin-A methylether. This reaction is a putative biosynthetic step in the biosynthesis of 6-methoxypodophyllotoxin from deoxypodophyllotoxin. The enzyme has a pH-optimum at pH 7.7 and a temperature optimum at 40 degrees C. The enzyme activity is strongly inhibited by MnSO(4), FeCl(3), FeSO(4) and ZnSO(4) as well as S-adenosyl-homocysteine. Mg(2+) and EDTA did not influence the methylation of beta-peltatin. Substrate saturation curves were obtained for S-adenosyl-methionine and beta-peltatin and apparent K(m)-values of 15 microM and 40 microM, respectively, were determined for these substrates. Substrate inhibition was observed for beta-peltatin. No other lignan substrate tested nor caffeic acid were accepted. The suspension cell line of Linum nodiflorum was characterized with respect to growth, medium alterations and lignan production as well as activity of SAM:beta-peltatin 6-O-methyltransferase. Highest specific activities of beta-peltatin 6-O-methyltransferase were determined on day 7 of the culture period corresponding to the highest levels of 6-methoxypodophyllotoxin on days 7 to 12. 相似文献