共查询到20条相似文献,搜索用时 15 毫秒
1.
Md. Abdullahil Baque Eun-Joo Hahn Kee-Yoeup Paek 《In vitro cellular & developmental biology. Plant》2010,46(1):71-80
An efficient protocol for adventitious root induction from leaf explants of Morinda citrifolia treated with different concentrations of indole-3-butyric acid (IBA) and α-naphthaleneacetic acid (NAA) was established in
relation to physiological process changes during adventitious root induction under different light sources (fluorescent, red,
blue, red + blue, and far-red). Among the different concentrations of IBA and NAA, 1.0 mg l−1 IBA was proven as the best auxin source for adventitious root induction under fluorescent light. Higher concentrations of
IBA and NAA trigger callus formation in both light and dark conditions. Maximum numbers of adventitious roots were induced
under red light (26) followed by blue light (22) and the lowest under far-red light (6). In contrast, numerous callus formations
were induced by red + blue followed by red and blue, while the highest root length (1.66 cm) with negligible callusing was
observed under fluorescent light. Catalase and guaicacol peroxidase activities were highest under red light followed by fluorescent
light and the lowest under red + blue light, but superoxide dismutase activity was not significantly influenced by different
light sources. Ascorbate peroxidase played an important role in detoxification of the harmful effects of hydrogen peroxide
(H2O2). Under fluorescent light, significantly lower accumulation of H2O2 was observed. Accumulation of H2O2 in the induced root under different light showed a positive correlation with peroxidation of lipids and was observed higher
under far-red followed by red + blue and blue light. 相似文献
2.
C. A. Martínez A. M. Giulietti J. Rodríguez Talou 《Plant Cell, Tissue and Organ Culture》2011,104(1):91-100
Hypericum perforatum L. (St. John’s wort) produces a number of phytochemicals having medicinal, anti-microbial, anti-viral and anti-oxidative
properties. Plant extracts are generally used for treatment of mild to medium cases of depression. Plant regeneration can
be achieved in this species by in vitro culture of a variety of explants. However, there are no reports of regeneration from
petal explants. In this report plant regeneration from petal explants of St. John’s wort was evaluated. Petals of various
ages were cultured on agarized Murashige and Skoog 1962 (MS) medium supplemented with auxin and cytokinin (kinetin), maintained in the dark and callus and shoot regeneration determined
after 28 days. At an auxin to cytokinin ratio of 10:1, callus and shoot formation were induced by all levels of indole-3-acetic
acid (IAA), indole-3-butyric acid (IBA) and 1-naphthaleneacetic acid (NAA), while 2,4-dichlorophenoxyacetic acid (2,4-D) induced
only callus formation. The optimum level of auxin for shoot regeneration was 1.0 and 0.1 mg/l kinetin, where the regeneration
frequency was 100 percent for all three auxins. The highest number of shoots per explant (57.4 and 53.4) was obtained with
IAA and IBA, respectively. In the absence of auxin, kinetin levels of 0.1 and 0.25 mg/l induce callus and shoot formation
at low frequency but not at lower levels. Callus and shoot formation did not occur in the absence of growth regulators. Petal-derived
shoots were successfully rooted on half-strength MS medium without a requirement for exogenous auxin and flowering plants
were established under greenhouse conditions. From these results it can be concluded that auxin type is a critical factor
for plant regeneration from petal explants of Hypericum perforatum and there is no absolute requirement for high levels of cytokinin. 相似文献
3.
4.
Two repeated DNA sequences isolated from a partial genomic DNA library of Helianthus annuus, p HaS13 and p HaS211, were shown to represent portions of the int gene of a Ty3 /gypsy retroelement and of the RNase-Hgene of a Ty1 /copia retroelement, respectively. Southern blotting patterns obtained by hybridizing the two probes to BglII- or DraI-digested genomic DNA from different Helianthus species showed p HaS13 and p HaS211 were parts of dispersed repeats at least 8 and 7 kb in length, respectively, that were conserved in all species studied. Comparable hybridization patterns were obtained in all species with p HaS13. By contrast, the patterns obtained by hybridizing p HaS211 clearly differentiated annual species from perennials. The frequencies of p HaS13- and p HaS211-related sequences in different species were 4.3x10(4)-1.3x10(5) copies and 9.9x10(2)-8.1x10(3) copies per picogram of DNA, respectively. The frequency of p HaS13-related sequences varied widely within annual species, while no significant difference was observed among perennial species. Conversely, the frequency variation of p HaS211-related sequences was as large within annual species as within perennials. Sequences of both families were found to be dispersed along the length of all chromosomes in all species studied. However, Ty3 /gypsy-like sequences were localized preferentially at the centromeric regions, whereas Ty1/ copia-like sequences were less represented or absent around the centromeres and plentiful at the chromosome ends. These findings suggest that the two sequence families played a role in Helianthusgenome evolution and species divergence, evolved independently in the same genomic backgrounds and in annual or perennial species, and acquired different possible functions in the host genomes. 相似文献
5.
6.
7.
Noel H. Holmgren 《Brittonia》2018,70(1):115-139
A revision of Penstemon sect. Saccanthera subsect. Serrulati includes a new species (P. salmonensis), a new variety (P. triphyllus var. infernalis), and the elevation of a subspecies to species (P. curtiflorus), bringing the total number of species to eight, which are keyed and described, complete with nomenclature and type citations. 相似文献
8.
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
9.
10.
11.
The effect of various hormonal combinations on regeneration of shoots and roots from meristem-derived callus of Crocus sativus L. and activities of antioxidant enzymes have been studied. The most efficient regeneration occurred with 1.0 mg dm−3 1-naphthaleneacetic acid (NAA) + 1.0 mg dm−3 thidiazuron and 1.0 mg dm−3 NAA + 2.0 mg dm−3 kinetin. For sprouting, regenerated shoot were subcultured on Murashige and Skoog medium containing 1.0 mg dm−3 NAA + 1.0 mg dm−3 benzylaminopurine (BAP). Protein content and superoxide dismutase activity decreased in regenerated shoots and roots and
increased in sprouting shoots, while catalase (CAT), peroxidase (POX) and polyphenol oxidase (PPO) activities increased during
organogenesis and decreased in sprouting shoots. High CAT and PPO activities were detected in regenerated roots, whereas high
POX activity was observed in regenerated shoot. 相似文献
12.
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
13.
V. R. Anbazhagan C. H. Ahn E. Harada Y. S. Kim Y. E. Choi 《In vitro cellular & developmental biology. Plant》2008,44(6):494-501
Podophyllum peltatum is an important medicinal plant that produces podophyllotoxin (PTOX) with anti-cancer properties. We established the embryogenic
cell and adventitious root culture systems in P. peltatum and analyzed PTOX production. For the growth of embryogenic cell clumps in shake flask culture, the most efficient concentration
of 2,4-dichloroacetic acid (2,4-D) was 6.78 μM, and the growth of embryogenic cell clumps was 15.9-fold increased in Murashige
and Skoog MS liquid medium with 6.78 μM 2,4-D after 3 wk of culture. To induce adventitious roots, half-strength MS medium
showed the best results for adventitious root induction compared to full strength MS medium and MS medium lacking NH4NO3. Optimal indole-3-butyric acid concentration for adventitious root formation was 14.78 μM. In liquid medium, the frequency
of adventitious root formation from root segments was 87.7% and the number of laterally formed adventitious roots was 22.3
per segment. PTOX production in embryogenic cells and adventitious roots was confirmed by liquid chromatography and electrospray
ionization–tandem mass spectrometry analysis. High-performance liquid chromatography analysis revealed that adventitious roots
contained higher PTOX than embryogenic cell clumps. Elicitor treatment (20 μM methyl jasmonate) strongly enhanced the production
of PTOX in both embryogenic cell clumps and adventitious roots. This observation suggests that both embryogenic cell and adventitious
root culture can be adopted to produce PTOX. 相似文献
14.
Richard H. Baltz 《Journal of industrial microbiology & biotechnology》2010,37(8):759-772
Natural products discovery from actinomycetes has been on the decline in recent years, and has suffered from a lack of innovative
ways to discover new secondary metabolites within a background of the thousands of known compounds. Recent advances in whole
genome sequencing have revealed that actinomycetes with large genomes encode multiple secondary metabolite pathways, most
of which remain cryptic. One approach to address the expression of cryptic pathways is to first identify novel pathways by
bioinformatics, then clone and express them in well-characterized hosts with known secondary metabolomes. This process should
eliminate the tedious dereplication process that has hampered natural products discovery. Several laboratory and industrial
production strains have been used for heterologous production of secondary metabolite pathways. This review discusses the
results of these studies, and the pros and cons of using various Streptomyces and one Saccharopolyspora strain for heterologous expression. This information should provide an experimental basis to help researchers choose hosts
for current application and future development to express heterologous secondary metabolite pathways in yields sufficient
for rapid scale-up, biological testing, and commercial production. 相似文献
15.
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
16.
Karolina Vrandecic Drazenka Jurkovic Luca Riccioni Jasenka Cosic Tomislav Duvnjak 《Mycopathologia》2010,170(1):51-60
Sunflower (Helianthus annuus) stem canker caused by Diaporthe helianthi is one of the most important sunflower diseases in Croatia. Until recently, sunflower was the only known host for D. helianthi. In our research carried out in the area of Eastern Croatia, isolates of Diaporthe/Phomospis were collected from Xanthium italicum, X. strumarium and Arctium lappa. Using morphological, cultural and molecular ITS rDNA data, isolates from these weeds were identified as D. helianthi. The following isolates were used in the pathogenicity test: one isolate originated from sunflower (Su5/04), three from X. italicum (Xa2, Xa3 and Xa5), two from X. strumarium (Xa9 and Xa12), one from Xanthium sp. (Xa13) and one from A. lappa (Ar3). According to the results, it was determined that isolate Xa5 (originated from X. italicum) was the most pathogenic to sunflower stems. The average length of the lesion was 11.3 cm. The lowest level of pathogenicity
was found in Xa9 (isolated from X. strumarium). The length of the lesion was 0.1 cm. 相似文献
17.
Zuping Cao Zhiwei Jia Yongjun Liu Meng Wang Jinfeng Zhao Jun Zheng Guoying Wang 《Molecular biology reports》2010,37(2):1089-1097
A small HSP gene, ZmsHSP, was isolated from Zea mays. Sequence analysis revealed that the open reading frame of ZmsHSP was 477 bp and that it encodes a protein composed of 159 amino acid residues with a calculated molecular mass of 18.17 kD
and a predicated isoelectric point (pI) of 5.63. ZmsHSP contains a CS domain (p23-like domain) and shares similarity with
the HSP90 co-chaperone p23. The expression level of ZmsHSP was different among various tissues with the highest expression in leaves and the lowest in silks. Results also showed that
the expression of ZmsHSP in maize was significantly up-regulated by dehydration. Transgenic Arabidopsis plants overexpressing ZmsHSP under the control of the CaMV 35S promoter had lower endogenous cytokinin content and showed more sensitivity to cytokinin
during the germination and early seedling stage than wild-type plants, suggesting that ZmsHSP might has a function in cytokinin response in Zea mays. 相似文献
18.
19.
20.
Song Quan Wu Mei Lan Lian Ri Gao So Young Park Xuan Chun Piao 《In vitro cellular & developmental biology. Plant》2011,47(6):719-724
Astragalus membranaceus is one of the most widely used traditional medicinal herbs in China, but the time required to generate a useful product in
the field production is long. The growth of adventitious root cultures was compared between cultures grown in solid, liquid,
or a 5-L balloon-type bubble bioreactor. The maximum growth ratio (final dry weight/initial dry weight) was determined for
adventitious roots grown in the bioreactor. Studies carried out to optimize biomass production of adventitious roots compared
adventitious root growth from various inoculum root lengths, inoculum densities, and aeration volume in the bioreactors. The
maximum growth ratio occurred in treatments with a 1.5-cm inoculum root length, with 30 g (fresh weight) of inoculum per bioreactor
or with an aeration volume of 0.1 vvm (air volume/culture medium volume per min). The polysaccharide, saponin, and flavonoid
content of roots from bioreactor-grown cultures were compared to roots from field-grown plants grown for 1 and 3 yr. Total
polysaccharide content of adventitious roots in the bioreactor (30.0 mg g−1 dry weight (DW)) was higher than the roots of 1-yr-old (13.8 mg g−1 DW) and 3-yr-old (21.1 mg g−1 DW) plants in the field. Total saponin (3.4 mg g−1 DW) and flavonoid (6.4 mg g−1 DW) contents were nearly identical to 3-yr-old roots and higher than that of 1-yr-old roots under field cultivation. 相似文献