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951.
Research on orchid biology and biotechnology 总被引:1,自引:0,他引:1
Hsiao YY Pan ZJ Hsu CC Yang YP Hsu YC Chuang YC Shih HH Chen WH Tsai WC Chen HH 《Plant & cell physiology》2011,52(9):1467-1486
Orchidaceae constitute one of the largest families of angiosperms. They are one of the most ecological and evolutionary significant plants and have successfully colonized almost every habitat on earth. Because of the significance of plant biology, market needs and the current level of breeding technologies, basic research into orchid biology and the application of biotechnology in the orchid industry are continually endearing scientists to orchids in Taiwan. In this introductory review, we give an overview of the research activities in orchid biology and biotechnology, including the status of genomics, transformation technology, flowering regulation, molecular regulatory mechanisms of floral development, scent production and color presentation. This information will provide a broad scope for study of orchid biology and serve as a starting point for uncovering the mysteries of orchid evolution. 相似文献
952.
Lin PR Tsai HP Tsui PY Weng MH Kuo MD Lin HC Chen KC Ji DD Chu DM Liu WT 《Applied and environmental microbiology》2011,77(10):3398-3405
Orientia tsutsugamushi is the etiological agent of scrub typhus, a mite-borne, febrile illness that occurs in the Asia-Pacific region. We conducted strain characterization of O. tsutsugamushi isolates from chiggers obtained from rodents based the nucleotide sequence of the 56-kDa outer membrane protein gene. With the use of PCR, a total of 68 DNA sequences of 56-kDa antigen genes were amplified. Phylogenetic analysis revealed that there were at least six definable clusters among the 68 isolates: 37% Karp-related strains (25/68), 27% TA763 strains (18/68), 12% JG-related strains (8/68), 19% Kato-related strains (13/68), 4% divergent strains (3/68), and 1% representing a Gilliam prototype strain (1/68). Overall, the O. tsutsugamushi genotypes exhibited a high degree of diversity, similar to that seen in strains from the rest of the areas where scrub typhus is endemic. Moreover, the 56-kDa protein sequence similarity between O. tsutsugamushi isolates from mites and those from human patients (H. Y. Lu et al., Am. J. Trop. Med. Hyg. 83:658-663, 2010) were striking, thus highlighting potential risk factors for this emerging zoonotic disease. 相似文献
953.
Two new species and one new variety of Elatostema J. R. Forst. & G. Forst. (Urticaceae) are described from Yunnan and Xizang, China. Habitat details and morphological comparison with similar species are given and discussed. The new taxa proposed are: Elatostema densistriolatum W. T. Wang & Zeng. Y. Wu, E. latistipulum W. T. Wang & Zeng Y. Wu and E. cyrtandrifolium (Zoll. & Mor.) Miq. var. hirsutum W. T. Wang & Zeng Y. Wu. 相似文献
954.
Unidirectional cross-activation of GRPR by MOR1D uncouples itch and analgesia induced by opioids 总被引:1,自引:0,他引:1
Liu XY Liu ZC Sun YG Ross M Kim S Tsai FF Li QF Jeffry J Kim JY Loh HH Chen ZF 《Cell》2011,147(2):447-458
Spinal opioid-induced itch, a prevalent side effect of pain management, has been proposed to result from pain inhibition. We now report that the μ-opioid receptor (MOR) isoform MOR1D is essential for morphine-induced scratching (MIS), whereas the isoform MOR1 is required only for morphine-induced analgesia (MIA). MOR1D heterodimerizes with gastrin-releasing peptide receptor (GRPR) in the spinal cord, relaying itch information. We show that morphine triggers internalization of both GRPR and MOR1D, whereas GRP specifically triggers GRPR internalization and morphine-independent scratching. Providing potential insight into opioid-induced itch prevention, we demonstrate that molecular and pharmacologic inhibition of PLCβ3 and IP3R3, downstream effectors of GRPR, specifically block MIS but not MIA. In addition, blocking MOR1D-GRPR association attenuates MIS but not MIA. Together, these data suggest that opioid-induced itch is an active process concomitant with but independent of opioid analgesia, occurring via the unidirectional cross-activation of GRPR signaling by MOR1D heterodimerization. 相似文献
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Background and Aims
In seeds with deep simple epicotyl morphophysiological dormancy, warm and cold stratification are required to break dormancy of the radicle and shoot, respectively. Although the shoot remains inside the seed all winter, little is known about its growth and morphological development prior to emergence in spring. The aims of the present study were to determine the temperature requirements for radicle and shoot emergence in seeds of Viburnum betulifolium and V. parvifolium and to monitor growth of the epicotyl, plumule and cotyledons in root-emerged seeds.Methods
Fresh and pre-treated seeds of V. betulifolium and V. parvifolium were incubated under various temperature regimes and monitored for radicle and shoot emergence. Growth of the epicotyl and cotyledons at different stages was observed with dissecting and scanning electron microscopes.Key Results
The optimum temperature for radicle emergence of seeds of both species, either kept continuously at a single regime or exposed to a sequence of regimes, was 20/10 °C. GA3 had no effect on radicle emergence. Cold stratification (5 °C) was required for shoot emergence. The shoot apical meristem in fresh seeds did not form a bulge until the embryo had grown to the critical length for radicle emergence. After radicle emergence, the epicotyl–plumule and cotyledons grew slowly at 5 and 20/10 °C, and the first pair of true leaves was initiated. However, the shoot emerged only from seeds that received cold stratification.Conclusions
Seeds of V. betulifolium and V. parvifolium have deep simple epicotyl morphophysiological dormancy, C1bB (root)–C3 (epicotyl). Warm stratification was required to break the first part of physiological dormancy (PD), thereby allowing embryo growth and subsequently radicle emergence. Although cold stratification was not required for differentiation of the epicotyl–plumule, it was required to break the second part of PD, thereby allowing the shoot to emerge in spring. 相似文献958.
Tsai CT Chiang FT Chen WP Hwang JJ Tseng CD Wu CK Yu CC Wang YC Lai LP Lin JL 《Cell calcium》2011,49(1):1-11
Angiotensin II (AngII) has been implicated in the mechanism of atrial fibrillation (AF). There may be calcium-dependent pro-fibrillatory effect of AngII on atrial myocytes. We used cultured confluent HL-1 atrial myocyte monolayer with spontaneously propagated depolarization to study direct pro-fibrillatory effect of AngII and its molecular mechanism. AngII stimulation induced fibrillatory-like complex electrogram and calcium wave propagation. AngII shortened action potential duration and augmented calcium transient, thus increasing electrochemical gradient of forward-mode sodium-calcium exchanger (NCX) current and induced frequent irregular afterdepolarizations. AngII increased expression of sodium-calcium exchanger (NCX), further increasing calcium-membrane voltage coupling gain. The fibrillatory effect of AngII was attenuated by NCX blocker SEA0400 and NCX siRNA knockdown. AngII increased expression of L-type calcium channel and augmented calcium transient through PKC and CREB. The fibrillatory effect of AngII was also attenuated by PKC inhibitor chelerythrine and dominant negative form of CREB. In conclusions, AngII itself may electrically contribute to the mechanism of AF through increasing NCX expression and augmenting calcium transient, which is PKC and CREB dependent. Specific genetic knockdown of NCX attenuated calcium mediated afterdepolarization and complex electrogram. 相似文献
959.
Efficient electron transfer from reductase domain to oxygenase domain in nitric oxide synthase (NOS) is dependent on the binding of calmodulin (CaM). Rate constants for the binding of CaM to NOS target peptides was only determined previously by surface plasmon resonance (SPR) (Biochemistry 35, 8742-8747, 1996) suggesting that the binding of CaM to NOSs is slow and does not support the fast electron transfer in NOSs measured in previous and this studies. To resolve this contradiction, the binding rates of holo Alexa 350 labeled T34C/T110W CaM (Alexa-CaM) to target peptides from three NOS isozymes were determined using fluorescence stopped-flow. All three target peptides exhibited fast kon constants at 4.5 °C: 6.6 × 108 M− 1 s− 1 for nNOS726-749, 2.9 × 108 M− 1 s− 1 for eNOS492-511 and 6.1 × 108 M− 1 s− 1 for iNOS507-531, 3-4 orders of magnitude faster than those determined previously by SPR. Dissociation rates of NOS target peptides from Alexa-CaM/peptide complexes were measured by Ca2+ chelation with ETDA: 3.7 s− 1 for nNOS726-749, 4.5 s− 1 for eNOS492-511, and 0.063 s− 1 for iNOS507-531. Our data suggest that the binding of CaM to NOS is fast and kinetically competent for efficient electron transfer and is unlikely rate-limiting in NOS catalysis. Only iNOS507-531 was able to bind apo Alexa-CaM, but in a very different conformation from its binding to holo Alexa-CaM. 相似文献
960.
Ping-Lung Huang Li-Jen Liao Chi-Chu Tsai Zin-Huang Liu 《Plant Cell, Tissue and Organ Culture》2011,105(1):73-78
Although suckers and seedlings can be used for the propagation of bromeliads, the low number of propagules and cross-variation
limit their uniformity and mass cultivation. In this study, high-efficiency shoot organogenesis and plant regeneration were
achieved on callus derived from petal and ovary explants of Aechmea fasciata (Bromeliaceae). Calluses were induced on half-strength Murashige and Skoog inorganic salts (1/2MS) supplemented with 1.0–1.5 mg
l−1 2,4-dichlorophenoxyacetic acid in combination with 1.0 or 0.5 mg l−1 α-naphthaleneacetic acid (NAA), and shoots regenerated after transfer to 1/2MS basal medium containing the combination of
1.0 mg l−1 NAA + 0.5 mg l−1 1-phenyl-3-(1,2,3-thiadiazol-5-yl) urea. Those plantlets grown under a middle light intensity (50 μmol m−2 s−1) showed a dramatic increase in survival percentage (up to 95%) and the maximum number of newly developing roots. The plantlets
that were transplanted onto pots were successfully grown in the greenhouse. 相似文献