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1.
A procedure for in vitro plant regeneration of Alnus acuminata from epicotyls with cotyledonary buds was developed using different media formulations with different growth regulators and carbon sources. The development of multiple buds on explants at the initiation step was obtained with MS at 1/2 strength with either 1 or 2M of BAP but not without it. Multiplication gave up to 15 elongating shoots by explant, the best medium being MS supplemented with vitamins from B5 medium, 1M of BAP and 87mM sucrose. Rooting of about 88% occurred in the medium MS with 83 mM sucrose and 1M IBA. Alnus acuminata did not developed well on WPM. Roots of in vitro propagated plants were nodulated by Alnus-infective Frankia. The root nodules show a typical alder root nodule anatomy and differentiation pattern and effectively fixed nitrogen. Rhamnaceae-infective Frankia did not nodulate in vitro cultivated Alnus acuminata suggesting that symbiotic recognition was not altered by in vitro regeneration of the plant. 相似文献
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Camptothecin-resistant fungal endophytes of <Emphasis Type="Italic">Camptotheca acuminata</Emphasis>
Concentrations of the DNA topoisomerase I inhibitor camptothecin were determined in different tissues of Camptotheca acuminata (Nyssaceae). The data were dependent on tissue type and developmental stage. Despite the presence of the toxic compound camptothecin,
nine endophytic fungi were isolated from healthy C. acuminata plants and were tested for their camptothecin sensitivity. Two isolates showed almost no inhibition at a camptothecin concentration
of 10 μg/ml. Even at a concentration of 100 μg/ml the inhibition was moderate. 相似文献
4.
Boonruangrod R Desai D Fluch S Berenyi M Burg K 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2008,118(1):43-55
Cytoplasmically inherited characters such as resistance to viral and fungal diseases, determination of starch types, crop
yield, resistance to low or high temperature often contribute to the advantageous phenotypic traits of plants. In the present
study, our goal was to elucidate the genealogy of cytoplasmic genomes chloroplast and mitochondria in banana. Banana breeding
is rather complicated because of the low fertility and mostly unknown origin of the edible cultivars, therefore, knowledge
on the putative fertile ancestors of cytoplasmic genomes chloroplast and mitochondria would be beneficial for breeding programmes.
Based on the established marker systems distinct species specific gene-pools could be identified for both chloroplast and
mitochondrial genomes for Musa acuminata and Musa balbisiana wild types, respectively. Detailed analysis of the species specific chloroplast and mitochondrial gene-pools of M.
acuminata and M.
balbisiana revealed six chloroplast and seven mitochondrial gene-pools in the analysed accessions. Comparative analysis of the haplotypes
revealed the presence of Primary Centers of origin for both chloroplast and mitochondrial genomes of both species supporting
the idea of common origin of these genomes. Cytotypes representing combinations of M. acuminata chloroplast and mitochondrial gene-pools were identified in majority of the analysed hybrid cultivars. A single M. acuminata cytotype was present in the majority of the analysed cultivars, which combination was not detected in any of the wild types.
On the other part a single balbisiana cytotype was identified participating in the formation of interspecies hybrids. The strong preference for the presence of
certain cytoplasmic gene-pools in cultivars may indicate hundreds of years of natural as well as of farmers’ selection supplementing
the phenotypic traits provided by the nuclear genome. Based on the present results the present day subspecies classification
of M. acuminata is also discussed. 相似文献
5.
A new species of the genus Camellia L. (Theaceae, Theoideae) is described and illustrated under the name C. cattienensis. This species occurs in the rainforest vegetation of Lam Dong Province, Vietnam. A discussion of the morphological characters
distinguishing this new species from related Camellia species is presented. Morphological evidence supports a transitional taxonomic placement in Camellia sect. Archaecamellia Sealy. This placement is justified by C. cattienensis exhibiting some morphological characteristics also found in sects Stereocarpus (Pierre) Sealy and Piquetia (Pierre) Sealy. 相似文献
6.
The Camptotheca acuminata cell suspension cultures were established to produce the well-known antitumor monoterpene indole alkaloid camptothecin (CAM). Most CAM was present in the broth of the C. acuminata cell suspension cultures. The CAM production was evidenced to be attenuated when the C. acuminata cell suspension cultures were continuously subcultured and grown under identical axenic conditions. A practical cryopreservation and recovery procedure was established to maintain the C. acuminata cell suspension cultures. Biotic and abiotic elicitors were administrated to the C. acuminata cell suspension cultures to restore and enhance CAM production. Of them, sorbitol, a well-known hyperosmotic stressor, was proven to be the most effective elicitor that stimulates a ~500-fold increase of CAM production. The committed biosynthetic precursors of CAM, tryptamine and secologanin, were feed to the C. acuminata cell suspension cultures and the CAM production is not remarkably increased. However, N 1-acetylkynuramine (NAK), an important metabolite of kynuramine pathway, was isolated and identified from the cell suspension cultures feeding with tryptamine. The present work provides an efficient method to produce CAM and NAK using the C. acuminata cell suspension cultures. The biotransformation of tryptamine to NAK sheds lights on the biosynthetic formation of the pyrroloquinoline moiety of CAM. 相似文献
7.
A bacterial artificial chromosome (BAC) library of banana (Musa acuminata) was used to select BAC clones that carry low amounts of repetitive DNA sequences and could be suitable as probes for fluorescence
in situ hybridization (FISH) on mitotic metaphase chromosomes. Out of eighty randomly selected BAC clones, only one clone gave a
single-locus signal on chromosomes of M. acuminata cv. Calcutta 4. The clone localized on a chromosome pair that carries a cluster of 5S rRNA genes. The remaining BAC clones
gave dispersed FISH signals throughout the genome and/or failed to produce any signal. In order to avoid the excessive hybridization
of repetitive DNA sequences, we subcloned nineteen BAC clones and selected their ‘low-copy’ subclones. Out of them, one subclone
gave specific signal in secondary constriction on one chromosome pair; three subclones were localized into centromeric and
peri-centromeric regions of all chromosomes. Other subclones were either localized throughout the banana genome or their use
did not result in visible FISH signals. The nucleotide sequence analysis revealed that subclones, which localized on different
regions of all chromosomes, contained short fragments of various repetitive DNA sequences. The chromosome-specific BAC clone
identified in this work increases the number of useful cytogenetic markers for Musa. 相似文献
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Dali Kang Hongli Zhang Qingqian Zeng Xiaolu Mo Yusheng Wang Depo Yang 《Acta Physiologiae Plantarum》2011,33(3):711-716
Plants in their natural environment are usually affected by mechanical stress because of their sessile growth habit. This
work was aimed at determining the effects of mechanical vibration on the growth rate, physiological indexes, and secondary
metabolite biosynthesis of Camptotheca acuminata calli. In this study, mechanical vibrations of 1–4 Hz in frequency were applied to stimulate the C. acuminata calli; we found that a mechanical vibration of moderate frequency (2 Hz) can clearly promote the growth rate and increase
the soluble protein content and superoxide dismutase (SOD) activity. Under a mechanical vibration of a 2 Hz frequency, camptothecin
(CPT), the main secondary metabolite produced by C. acuminata, was increased by about fourfold compared to the control group, In contrast, the increased accumulation disappears at higher
frequencies. The optimal vibration time for obtaining the highest levels of biomass and CPT was 60 min. This study showed
that there are neutral frequencies and optimal periods of mechanical vibration on C. acuminata calli. 相似文献
10.
A new 10-hydroxycamptothecin (HCPT)-producing fungus was isolated from Camptotheca
acuminata. The strain was classified as a Xylaria sp. based on the internal transcribed spacer and 18S rDNA gene analysis. All elicitors tested, except methyl jasmonate, increased
HCPT production in submerged culture. The maximum yield was 5.4 mg HCPT/l−1, when salicylic acid was added at 0.1 mM to the culture medium 相似文献
11.
The maT clade of transposons is a group of transposable elements intermediate in sequence and predicted protein structure to mariner and Tc transposons, with a distribution thus far limited to a few invertebrate species. We present evidence, based on searches of publicly available databases, that the nematode Caenorhabditis briggsae has several maT-like transposons, which we have designated as CbmaT elements, dispersed throughout its genome. We also describe two additional transposon sequences that probably share their evolutionary history with the CbmaT transposons. One resembles a fold back variant of a CbmaT element, with long (380-bp) inverted terminal repeats (ITRs) that show a high degree (71%) of identity to CbmaT1. The other, which shares only the 26-bp ITR sequences with one of the CbmaT variants, is present in eight nearly identical copies, but does not have a transposase gene and may therefore be cross mobilised by a CbmaT transposase. Using PCR-based mobility assays, we show that CbmaT1 transposons are capable of excising from the C. briggsae genome. CbmaT1 excised approximately 500 times less frequently than Tcb1 in the reference strain AF16, but both CbmaT1 and Tcb1 excised at extremely high frequencies in the HK105 strain. The HK105 strain also exhibited a high frequency of spontaneous induction of unc-22 mutants, suggesting that it may be a mutator strain of C. briggsae. 相似文献
12.
Summary Camptothecin, produced by Camptotheca acuminata, is a pharmaceutically important compound. Transgenic technology has potential uses for the enhancement of camptothecin production;
however, an efficient plant regeneration protocol for C. acuminata is not currently available. Factors that affected successful seedling germination were evaluated. The regeneration potential
of various parts of seedlings was tested. Camptothecin production in regenerated plants was compared to its production in
calluses and the original seedlings. Dark incubation and seed coat removal led to a higher germination rate and a higher survival
rate after germination. The best shoot induction medium was found to be Gamborg's B5 medium+8.9 μM benzyladenine. Among the calluses induced from various parts of seedlings, leaf petiole calluses, leaf dise calluses, and
cotyledon calluses regenerated shoots, but internode calluses did not. Furthermore, leaf petiole calluses and leaf dise calluses
regenerated normal shoots, while cotyledon calluses regenerated hyperhydric shoots. Moreover, leaf petiole calluses had a
higher shoot regeneration rate, 50% versus 9%, and a higher shoot number, 6.2±0.5 versus 2.0±0.3, than did leaf dise calluses
on the best shoot induction medium. It took 4–6 wk to regenerate shoots after transfer into shoot induction media. Camptothecin
concentration in the regenerated plants was significantly higher than that in the calluses and similar to that in the original
seedlings. In conclusion, leaf petioles provide efficient plant regeneration of C. acuminata. 相似文献
13.
Studying Pneumocystis has proven to be a challenge from the perspective of propagating a significant amount of the pathogen in a facile manner.
The study of several fungal pathogens has been aided by the use of invertebrate model hosts. Our efforts to infect the invertebrate
larvae Galleria
mellonella with Pneumocystis proved futile since P. murina neither caused disease nor was able to proliferate within G. mellonella. It did, however, show that the pathogen could be rapidly cleared from the host. 相似文献
14.
A genetic transformation system has been developed for callus cells of Crataegus
aronia using Agrobacterium
tumefaciens. Callus culture was established from internodal stem segments incubated on Murashige and Skoog (MS) medium supplemented with
5 mg l−1 Indole-3-butyric acid (IBA) and 0.5 mg l−1 6-benzyladenine (BA). In order to optimize the callus culture system with respect to callus growth and coloration, different
types and concentrations of plant growth regulators were tested. Results indicated that the best average fresh weight of red
colored callus was obtained on MS medium supplemented with 2 mg l−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.5 mg l−1 kinetin (Kin) (callus maintenance medium). Callus cells were co-cultivated with Agrobacterium harboring the binary plasmid pCAMBIA1302 carrying the mgfp5 and hygromycin phosphotransferase (hptII) genes conferring green fluorescent protein (GFP) activity and hygromycin resistance, respectively. Putative transgenic calli
were obtained 4 weeks after incubation of the co-cultivated explants onto maintenance medium supplemented with 50 mg l−1 hygromycin. Molecular analysis confirmed the integration of the transgenes in transformed callus. To our knowledge, this
is the first time to report an Agrobacterium-mediated transformation system in Crataegus
aronia. 相似文献
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Franc-Christophe Baurens Stéphanie Bocs Mathieu Rouard Takashi Matsumoto Robert NG Miller Marguerite Rodier-Goud Didier MBéguié-A-MBéguié Nabila Yahiaoui 《BMC plant biology》2010,10(1):149
Background
Comparative sequence analysis of complex loci such as resistance gene analog clusters allows estimating the degree of sequence conservation and mechanisms of divergence at the intraspecies level. In banana (Musa sp.), two diploid wild species Musa acuminata (A genome) and Musa balbisiana (B genome) contribute to the polyploid genome of many cultivars. The M. balbisiana species is associated with vigour and tolerance to pests and disease and little is known on the genome structure and haplotype diversity within this species. Here, we compare two genomic sequences of 253 and 223 kb corresponding to two haplotypes of the RGA08 resistance gene analog locus in M. balbisiana "Pisang Klutuk Wulung" (PKW). 相似文献17.
18.
Kurtzman CP 《Antonie van Leeuwenhoek》2011,100(3):455-462
Ogataea
parapolymorpha sp. n. (NRRL YB-1982, CBS 12304, type strain), the ascosporic state of Candida
parapolymorpha, is described. The species appears homothallic, assimilates methanol as is typical of most Ogataea species and forms hat-shaped ascospores in asci that become deliquescent. O. parapolymorpha is closely related to Ogataea
angusta and Ogataea
polymorpha. The three species can be resolved from gene sequence analyses but are unresolved from fermentation and growth reactions
that are typically used for yeast identification. On the basis of multiple isolates, O. angusta is known only from California, USA, in association with Drosophila and Aulacigaster flies, O. parapolymorpha is predominantly associated with insect frass from trees in the eastern USA but O. polymorpha has been isolated from various substrates in the USA, Brazil, Spain and Costa Rica. 相似文献
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We have investigated the floral ontogeny of Arillastrum, Allosyncarpia, Stockwellia and Eucalyptopsis (of the eucalypt group, Myrtaceae) using scanning electron microscopy and light microscopy. Several critical characters for establishing relationships between these genera and to the eucalypts have been determined. The absence of compound petaline primordia in Arillastrum, Allosyncarpia, Stockwellia and Eucalyptopsis excludes these taxa from the eucalypt clade. Post-anthesis circumscissile abscission of the hypanthium above the ovary in Stockwellia, Eucalyptopsis and Allosyncarpia is evidence that these three taxa form a monophyletic group; undifferentiated perianth parts and elongated fusiform buds are characters that unite Stockwellia and Eucalyptopsis as sister taxa. No floral characters clearly associate Arillastrum with either the eucalypt clade or the clade of Stockwellia, Eucalyptopsis and Allosyncarpia.We gratefully acknowledge Clyde Dunlop and Bob Harwood (Northern Territory Herbarium) for collecting specimens of Allosyncarpia, and Bruce Gray (Atherton) for collecting specimens of Stockwellia. The Australian National Herbarium (CANB) kindly lent herbarium specimens of Eucalyptopsis for examination. This research was supported by a University of Melbourne Research Development Grant to Andrew Drinnan. 相似文献