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1.
Fang Chang An Yan Li-Na Zhao Wei-Hua Wu Zhenbiao Yang 《植物学报(英文版)》2007,49(8):1261-1270
A tip-focused Ca^2+ gradient is tightly coupled to polarized pollen tube growth, and tip-localized influxes of extracellular Ca^2+ are required for this process. However the molecular identity and regulation of the potential Ca^2+ channels remains elusive. The present study has implicated CNGC18 (cyclic nucleotide-gated channel 18) in polarized pollen tube growth, because its overexpression induced wider and shorter pollen tubes. Moreover, CNGC18 overexpression induced depolarization of pollen tube growth was suppressed by lower extracellular calcium ([Ca^2+]ex). CNGC18-yellow fluorescence protein (YFP) was preferentially localized to the apparent post-Golgi vesicles and the plasma membrane (PM) in the apex of pollen tubes. The PM localization was affected by tip-localized ROP1 signaling. Expression of wild type ROP1 or an active form of ROP1 enhanced CNGC18-YFP localization to the apical region of the PM, whereas expression of RopGAP1 (a ROP1 deactivator) blocked the PM localization. These results support a role for PM-Iocalized CNGC18 in the regulation of polarized pollen tube growth through its potential function in the modulation of calcium influxes. 相似文献
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The effect of endothelin-1 has been examined on isolated spontaneously beating right atria and electrically driven left atria from diabetic rats and age-matched controls. Diabetes was induced by a single i.v. injection of streptozotocin (65 mg/kg) 4–5 weeks before the experiments. Endothelin-1 (0.01–100 nM) caused concentration-dependent increases in atrial rate and force; the increases were not different between atria from diabetic and control rats. The ability of endothelin-1 to reduce chronotropic and inotropic responses to noradrenaline was also not different between the two groups. Endothelin-1 (10 nM) decreased the chronotropic response to sympathetic nerve stimulation (2 Hz, 10 s) in atria from control rats by 68 ± 5% (n = 8), but this decrease was slightly smaller (45 ± 6%, N = 8) in atria from diabetic rats.
The results provide no evidence to suggest that the diabetic state markedly alters cardiac responses to endothelin-1. 相似文献
5.
Transformation of Tobacco, Tomato, Potato, and Arabidopsis thaliana Using a Binary Ti Vector System 总被引:16,自引:1,他引:15 下载免费PDF全文
Using a binary tumor-inducing (Ti) plasmid vector system, several plant species were transformed with a kanamycin resistance marker (neomycin phosphotransferase gene). Four Nicotiana species, seven tomato cultivars, two potato cultivars, and Arabidopsis thaliana were transformed by the binary vector transformation method. In this method, various plant organ pieces were co-cultivated with Agrobacterium tumefaciens cells carrying the binary vector, pGA472, and a helper Ti plasmid. We have also demonstrated that a wild type Ti plasmid can be used as a helper to obtain a transformed plant. 相似文献
6.
In vitro growth and differentiation of human kidney tubular cells on a basement membrane substrate 总被引:4,自引:0,他引:4
An Hang Yang Jeanine Gould-Kostka Terry D. Oberley 《In vitro cellular & developmental biology. Plant》1987,23(1):34-46
Summary Kidney cortical tubular cells, mainly proximal tubular cells, isolated from human kidney and grown either on a basement membrane
substrate in chemically defined medium or on plastic in serum-supplemented medium, had substantial proliferative potential
and could be propagated for more than 10 generations or 8 passages before senescence. Basement membrane produced on a plastic
substrate by the HR-9 endodermal cell line could replace serum supplementation in promoting tubular cell growth. Tubular cells
grown on an HR-9 basement membrane substrate exhibited stable epithelial morphology over an extended period of time; in the
presence of 5% serum they differentiated into organized structures such as hemicysts and cell cords. Cells grown on plastic
failed to differentiate and gradually degenerated. Tubular cells on HR-9 basement membrane were characterized by densely packed
microvilli, abundant rough endoplasmic reticulum and free polysomes, basal cell membrane interdigitations, a well-developed
endocytotic apparatus, and conspicuous junctional complexes—all features of the proximal tubular cell. Compared with cells
on plastic substrate, there were higher levels of the brush border enzymes γ-glutamyl transpeptidase,l-leucine aminopeptidase, and alkaline phosphatase in cells maintained on an HR-9 basement membrane substrate, further supporting
the conclusion that a basement membrane substrate promoted differentiation of tubular cells. These data and morphological
observations indicate that a basement membrane substrate can promote growth and both functional and morphologic differentiation
of human kidney tubular cells.
This work was supported by the Veterans Administration. 相似文献
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倭竹属地理分布的研究 总被引:2,自引:0,他引:2
倭竹属Shibataea Makino隶于禾本科之竹亚科,现已知有8种,分布于我国东南部的浙江、福建、江苏、安徽、江西等省,广东、台湾两省有少量栽培,日本产1种。苏联、西德、印尼等国所栽培的倭竹均系自我国或日本引入。我国浙-闽地区产8种,且都有野生发现,是本属的现代分布中心。倭竹属植物体型矮小,常植于庭院或公园中供观赏。近年来盆景艺术迅速发展,微型园林日益兴起,倭竹属植物体态优美,常绿,耐寒且易于栽培,为广大园林工作者所垂青。 相似文献
9.
Nucleotide sequence of the sex pheromone inhibitor (iAD1) determinant of Enterococcus faecalis conjugative plasmid pAD1 总被引:17,自引:0,他引:17
The determinant for the peptide sex pheromone inhibitor iAD1 (iad) on the hemolysin/bacteriocin plasmid pAD1 of Enterococcus faecalis was sequenced. The sequence reveals a 22-amino-acid precursor with the carboxyl-terminal 8 residues corresponding to iAD1. It appears that iAD1 is a component of its own signal sequence. 相似文献
10.
An De Bondt Kristel Eggermont Iris Penninckx Inge Goderis Willem F. Broekaert 《Plant cell reports》1996,15(7):549-554
We have previously developed a protocol for efficient gene transfer and regeneration of transgenic calli following cocultivation of apple (cv. Jonagold) explants with Agrobacterium tumefaciens (De Bondt et al. 1994, Plant Cell Reports 13: 587–593). Now we report on the optimization of postcultivation conditions for efficient and reproducible regeneration of transgenic shoots from the apple cultivar Jonagold. Factors which were found to be essential for efficient shoot regeneration were the use of gelrite as a gelling agent and the use of the cytokinin-mimicing thidiazuron in the selective postcultivation medium. Improved transformation efficiencies were obtained by combining the hormones thidiazuron and zeatin and by using leaf explants from in vitro grown shoots not older than 4 weeks after multiplication. Attempts to use phosphinothricin acetyl transferase as a selectable marker were not successful. Using selection on kanamycin under optimal postcultivation conditions, about 2% of the leaf explants developed transgenic shoots or shoot clusters. The presence and expression of the transferred genes was verified by -glucuronidase assays and Southern analysis. The transformation procedure has also been succesfully applied to several other apple cultivars.Abbreviations BAP
benzylaminopurine
- CTAB
hexadecyltrimethylammoniumbromide
- Na2EDTA
ethylenediamine-tetra-acetate ferric-sodium salt
- FeNaEDTA
ethylenediamine-tetra-acetate ferric-sodium salt
- GA3
gibberellic acid 3
- GusA
-glucuronidase
-
gusA
-glucuronidase gene of Escherichia coli
- IAA
indole acetic acid
- IBA
indole butyric acid
- 2iP
N6-2-isopentenyl adenine
- NAA
naphthalene acetic acid
-
nptII
neomycinphosphotransferase II gene
-
bar
phosphinothricin acetyl transferase gene
- PCR
polymerase chain reaction
- PPT
phosphinothricin
- STS
silver thiosulphate
- T-DNA
transferred DNA
- TDZ
thidiazuron
- X-Gluc
5-bromo-4-chloro-3-indolyl -D-glucuronide
- Zea
trans-Zeatin 相似文献