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K Mizuno 《Cell biology international reports》1985,9(1):13-21
Tubulins were isolated by a combination of affinity (ethyl N-phenylcarbamate-Sepharose 4B) and ion exchange (DEAE-Sephacel) chromatography from several higher plants (mung bean, pea, whole pod bean, zucchini, cucumber seedlings and carrot suspension cultured cells). All these higher plant tubulins readily polymerized to microtubules in a polymerization medium containing GTP, Mg2+, EGTA, leupeptin and DMSO. Tubulins from mung bean, pea and whole pod bean showed identical behaviour on polyacrylamide gel electrophoresis but differed from carrot zucchini and cucumber tubulin. Consequently, tubulin of higher plants seems to have different molecular properties in different plant species. 相似文献
3.
Chi-Chang Chen 《In vitro cellular & developmental biology. Plant》1977,13(8):484-489
Summary Rice (Oryza sativa L., 2n=24) anthers containing microspores in the early-uninucleate to first-mitosis stages were induced successfully to develop
into plants in vitro through an intermediary step of callus formation. Callus initiation occurred with highest frequency in
anthers containing mid-uninucleate microspores. The callus derived from different stages of microspore development differed
in the potential to differentiate into plants. The plants regenerated from pollen callus were predominantly haploid or diploid;
polyploid and aneuploid plants were relatively infrequent. The first division of the uninucleate microspores was asymmetrical,
resulting in the formation of large vegetative and small generative nuclei. The vegetative nucleus divided repeatedly and
assumed the major role in the formation of callus, whereas the generative nucleus degenerated rapidly. Simultaneous division
of the two nuclei was observed in a few pollen grains. Nuclear fusion during the very initial stages of pollen development
was postulated to account for the occurrence of the diploid and polyploid plants.
This work was supported by the National Science Council, Republic of China. 相似文献
4.
Two-dimensional crystals of the photosystem II reaction center complex from higher plants 总被引:2,自引:0,他引:2
R Bassi A Ghiretti Magaldi G Tognon G M Giacometti K R Miller 《European journal of cell biology》1989,50(1):84-93
By detergent treatment of isolated photosynthetic membranes from maize chloroplasts, we have prepared two-dimensional crystals of the photosystem II complex. Two distinct crystal forms are produced by this treatment. Analysis of Fourier transforms of the crystals shows that each crystal type is formed from two inverted layers. Within the rectangular 17.8 x 26.7 nm unit cell of each layer is a tetrameric structure enclosing a two-fold symmetry axis, a result implying that the basic structural unit of photosystem II is dimeric. Tris-washing, which removes proteins associated with the oxygen-evolving apparatus from the inner surface of the photosynthetic membrane, causes a distinct change in the structure of these tetramers and reveals a dimeric core complex which may be directly associated with the photosystem II machinery. 相似文献
5.
Metabolic engineering of ketocarotenoid formation in higher plants 总被引:15,自引:0,他引:15
Ralley L Enfissi EM Misawa N Schuch W Bramley PM Fraser PD 《The Plant journal : for cell and molecular biology》2004,39(4):477-486
Although higher plants synthesize carotenoids, they do not possess the ability to form ketocarotenoids. In order to generate higher plants capable of synthesizing combinations of ketolated and hydroxylated carotenoids the genes responsible for the carotene 4,4' oxygenase and 3,3' hydroxylase have been transformed into tomato and tobacco. The gene products were produced as a polyprotein. Subsequent cleavage of the polyprotein, targeting of the two enzymes to the plastid and enzyme activities have been shown for both gene products. Metabolite profiling has shown the formation of ketolated carotenoids from beta-carotene and its hydroxylated intermediates in tobacco and tomato leaf. In the nectary tissues of tobacco flowers a quantitative increase (10-fold) as well as compositional changes were evident, including the presence of astaxanthin, canthaxanthin and 4-ketozeaxanthin. Interestingly, in this tissue the newly formed carotenoids resided predominantly as esters. These data are discussed in terms of metabolic engineering of carotenoids and their sequestration in higher plant tissues. 相似文献
6.
Köhler I Jenett-Siems K Siems K Hernández MA Ibarra RA Berendsohn WG Bienzle U Eich E 《Zeitschrift für Naturforschung. C, Journal of biosciences》2002,57(3-4):277-281
In vitro antiplasmodial activities of extracts from Albizia saman, Fabaceae, Calea tenuifolia (C. zacatechichi), Asteraceae, Hymenaea courbaril, Fabaceae, Jatropha curcas, Euphorbiaceae, Momordica charantia, Cucurbitaceae, and Moringa oleifera, Moringaceae were evaluated. From the lipophilic extract of C tenuifolia five active flavones were obtained. 4',5-Dihydroxy-7-methoxyflavone [genkwanin] and 5-hydroxy-4',7-dimethoxyflavone [apigenin 4',7-dimethylether] exhibited the strongest antiplasmodial activity against a chloroquine-sensitive strain (poW) and a chloroquine-resistant strain (Dd2) of Plasmodium falciparum [IC50 values: 17.1-28.5 microM). Furthermore octadeca-9,12-dienoic acid [linoleic acid] [IC50] values of 21.8 microM (poW) and 31.1 microM (Dd2)] and octadeca-9,12,15-trienoic acid (alpha-linolenic acid) were isolated. 相似文献
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The shoot apical meristem (SAM) is essential for organ formation in higher plants. How the SAM is formed during plant development
is poorly understood, however. In this review, we focus on several recent studies that provide new insights into the mechanism
of SAM formation during embryogenesis. Recently, positive and negative regulators of the class I KNOX genes, which are thought to be necessary for SAM formation, have been identified; the Arabidopsis CUP-SHAPED COTYLEDON (CUC) genes are required for the expression of a class I KNOX gene, SHOOT MERISSTEMLES (STM) during embryogenesis, and the Arabidopsis ASYMMETRIC LEAVES1 (AS1), AS2, and several other genes negatively regulate KNOX gene expression in cotyledon primordia. Also, several genes that are involved in the formation of the adaxial–abaxial axis
of cotyledons seem to regulate embryonic SAM formation.
Electronic Publication 相似文献
9.
In vitro production of haploid plants 总被引:1,自引:0,他引:1
A. Atanassov N. Zagorska P. Boyadjiev D. Djilianov 《World journal of microbiology & biotechnology》1995,11(4):400-408
Although several methods have been developed for producing haploid plants, the in vitro techniques are much more efficient than inter-specific hybridization or treatment with plant-growth regulators, temperature or irradiation. Androgenesis is the most universal of these techniques but ovule culture and the bulbosum method could complement or replace anther culture in those species or genotypes with less responsive male gametes. Genotype, environment, physiological status of the donor plant, and culture conditions and components all need to be taken into account when developing procedures for producing haploid and dihaploid plants. Suitable methods are already well established for a number of important crops. However, many problems, related to regeneration frequency, gametoclonal variation and albinism, are still unsolved. It is now clear that haploids and dihaploids form the ideal system for genetic manipulation in plants. Their key role in producing new theoretical and applied knowledge in plant science is an important aspect of our review.A. Atanassov is with the De Montfort University Norman Borlaug Center for Plant Science Research, Institute of Genetic Engineering, 2232 Kostinbrod, Bulgaria; N. Zagorska is with the Institute of Genetics, 1113 Sofia, Bulgaria. P. Boyadjiev is with the Institute of Plant Introduction and Genetic Resources, 4122 Sadovo, Bulgaria D. Djilianov is with the Institute of Genetic Engineering, 2232 Kostinbrod-2, Bulgaria. 相似文献
10.
《Phytochemistry》1987,26(9):2439-2446
Work on isocitrate lyase, the first enzyme unique to the glyoxylate cycle, is reviewed. 相似文献
11.
Hypocotyl segments, 5 to 8 mm length from 4 to 7 day old seedlings, callused on B5 medium supplemented with Kn (0.5 ppm) and NAA (0.1 ppm). Even without transfer, shoots were formed in such cultures. About 20% of the cultures produced multiple shoots. In medium with 1 ppm each of Kn and NAA direct shoots were formed at one end of the hypocotyl segment and callusing was initiated at the other end. The plants obtained in either medium formed roots and could be transferred to soil for further growth.Abbreviations BA
benzyladenine
- 2,4-D
2,4-dichlorophenoxy acetic acid
- GA3
gibberellic acid
- Kn
Kinetin
- NAA
naphthalene acetic acid 相似文献
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Summary Protoplasts were isolated from cell suspensions of Haplopappus gracilis. The cell walls were degraded by the cellulase preparation Onozuka P 1500 at a concentration of 5%. Sorbitol was found to work well as osmotic stabilizer in concentrations of 0.4–0.6 M. The protoplasts were cultured in growth medium after isolation; 3–5% went through nuclear division once and less than 1% also for a second time. No nuclear fusion was observed. 相似文献
14.
A rapid in vitro shoot-tip grafting (STG) technique was adapted to increase recovery of intact cotton plants from shoots developed in culture.
Induction of root organogenesis in cotton shoots is genotype dependent and unreliable. The resulting loss of regeneration
potential due to failure to form roots can vary from 30 to 80% according to genotype and represents a significant bottleneck
in the overall recovery of plants from culture. If the non-rooting shoots are transgenic, the loss in regenerated plant material
can be substantial. In vitro grafting of cotton shoots to seedling rootstock proved to be a simple and reliable method allowing 90–100% recovery of non-rooting
shoots from culture. Success of any given graft was directly related to scion size (0.8–1.0 cm) and age (14–35 days) of the
seedling rootstock. The method appeared to be genotype independent, and varietal differences between rootstock and scion did
not effect the rate of plant recovery from culture.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
15.
José Nobre 《Plant Cell, Tissue and Organ Culture》1996,46(2):151-155
In vitro clonal propagation of native Mediterranean Lavandula stoechas has been achieved from mature field-grown plants. Procedures have been developed for reducing shoot hyperhydricity during in vitro culture establishment and shoot multiplication stages. Shoot multiplication was obtained, in 4–5 weeks, from single node explants cultured on a basal medium containing Margara N30K macrosalts and supplemented with 217.2 M adenine hemisulphate (AdS) and 0.05 M NAA. In vitro rooting (100%) of the shoots was observed on basal medium containing 5.4 M NAA.Abbreviations BA
N6-benzyladenine
- AdS
adenine hemi-sulphate
- GA3
gibberellic acid
- NAA
1-naphthaleneacetic acid
- PVP
polyvinylpyrrolidone 相似文献
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Cyanide metabolism in higher plants. V. The formation of asparagine from -cyanoalanine 总被引:8,自引:0,他引:8
β-Cyanoalanine hydrolase, an enzyme which catalyzes the formation of asparagine from β-cyanoalanine, has been isolated from the soluble fraction of the cotyledons and shoots of 11-day-old etiolated blue lupin seedlings. The enzyme can be assayed radio-chemically by measuring the incorporation of label from β-[4-14C]cyano-l-alanine into asparagine, or colorimetrically by estimating the ammonia produced by Nesslerization after hydrolysis of the asparagine formed during the incubation. The enzyme has been purified some 250–300 fold, though not to homogeneity, with an overall yield of 15%. β-Cyanoalanine hydrolase has a pH optimum of about 8.5 and a molecular weight of 400,000–500,000 estimated from its elution volume on Sepharose 6B. A Km of 2.0 mm for β-cyanoalanine was determined. 相似文献
19.
B. Sharma H. C. Bansal 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1972,42(1):25-31
Summary After treatment of dry and pre-soaked seeds of barley with gamma-rays, EMS, NEU and EI, the frequency of multiple mutations (multimutations) was higher with EMS and NEU treatment, while cluster mutations appeared in greater numbers following treatment with gamma rays and NEU. Pre-soaking the seeds led to a reduction in the frequency of total mutations, cluster mutations and multimutations. This has been explained as a result of the application of lower doses and the induction of mutations at a relatively later stage in ontogenetic development in the case of pre-soaked seeds.Some new mutation types in barley have been described and some of the old types have been given names representing the mutation characters more precisely.The compound mutation frequency of different seedling mutation types, when taken separately, was found to be independent of the mutagen employed and the stage of treatment. The size of mutated chimeras in M
1 plants, as indicated by the segregation ratio of mutants in M
2, was largest in albina, xantha, chlorina, albina-tigrina, chl-terminalis and eceriferum, and lowest in viridis, viridoalbina etc. This could be expected if the unstable premutations induced by mutagenic treatment are resolved into mutations at different intervals after their initiation, or it can be explained by the induction of dominant mutations, or lethal changes together with visible mutations. 相似文献
20.
Vladimir A. Fedorov Ilya B. Kovalenko Sergei S. Khruschev Dmitry M. Ustinin Taras K. Antal Galina Y. Riznichenko Andrei B. Rubin 《Physiologia plantarum》2019,166(1):320-335
Mechanisms of the complex formation between plastocyanin and cytochrome f in higher plants (Spinacia oleracea and Brassica rapa), green microalgae Chlamydomonas reinhardtii and two species of cyanobacteria (Phormidium laminosum and Nostoc sp.) were investigated using combined Brownian and molecular dynamics simulations and hierarchical cluster analysis. In higher plants and green algae, electrostatic interactions force plastocyanin molecule close to the heme of cytochrome f. In the subsequent rotation of plastocyanin molecule around the point of electrostatic contact in the vicinity of cytochrome f, copper (Cu) atom approaches cytochrome heme forming a stable configuration where cytochrome f molecule behaves as a rather rigid body without conformational changes. In Nostoc plastocyanin molecule approaches cytochrome f in a different orientation (head‐on) where the stabilization of the plastocyanin–cytochrome f complex is accompanied by the conformational changes of the G188E189D190 loop that stabilizes the whole complex. In cyanobacterium P. laminosum, electrostatic preorientation of the approaching molecules was not detected, thus indicating that random motions rather than long‐range electrostatic interactions are responsible for the proper mutual orientation. We demonstrated that despite the structural similarity of the investigated electron transport proteins in different photosynthetic organisms, the complexity of molecular mechanisms of the complex formation increases in the following sequence: non‐heterocystous cyanobacteria – heterocystous cyanobacteria – green algae – flowering plants. 相似文献