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21.
3种植物生长调节剂对树头菜扦插生根的影响 总被引:2,自引:0,他引:2
利用植物生长调节剂不同种类及质量浓度处理树头菜插穗,了解其扦插生根机制并筛选出适宜扦插繁殖的生长调节剂及浓度配比,为其扩大繁殖和生产提供科学依据。以树头菜一年生枝条为材料,采用3种植物生长调节剂(IAA、NAA、ABT-1)的3种不同质量浓度进行正交试验,清水处理(CK)作为对照,扦插3个月后对其芽生长量及生根性状(生根率、生根量、最长根长、平均根长等)进行测定并综合分析。本次试验筛选出的树头菜扦插最优方案为A1B2C2,即ABT-1质量浓度为50 mg·L-1、NAA质量浓度为200 mg·L-1、IAA质量浓度为200 mg·L-1,该处理生根率(83.33%)、平均根长(24.03 mm)、最长根长(46.13 mm)、平均根数(24条)、根系效果指数(19.06)为CK的2.27、2.97、3.03、4.50、12.79倍,根系发育较好。不同植物生长调节剂在适宜的浓度下混合利用可以显著增加树头菜的生根能力,进而加快生长并提高其扦插生根率。 相似文献
22.
Fujita A 《Biochemical and biophysical research communications》2008,366(1):193-198
Small GTPases act as molecular switches in a wide variety of cellular processes. In fission yeast Schizosaccharomyces pombe, the directions of cell growth change from a monopolar manner to a bipolar manner, which is known as ‘New End Take Off’ (NETO). Here I report the identification of a gene, arf6+, encoding an ADP-ribosylation factor small GTPase, that may be essential for NETO. arf6Δ cells completely fail to undergo NETO. arf6p localizes at both cell ends and presumptive septa in a cell-cycle dependent manner. And its polarized localization is not dependent on microtubules, actin cytoskeletons and some NETO factors (bud6p, for3p, tea1p, tea3p, and tea4p). Notably, overexpression of a fast GDP/GTP-cycling mutant of arf6p can advance the timing of NETO. These findings suggest that arf6p functions as a molecular switch for the activation of NETO in fission yeast. 相似文献
23.
Domestic pig (Sus scrofa domestica) is one of the most important mammals to humans. Alternative splicing is a cellular mechanism in eukaryotes that greatly increases the diversity of gene products. Expression sequence tags (ESTs) have been widely used for gene discovery, expression profile analysis, and alternative splicing detection. In this study, a total of 712,905 ESTs extracted from 101 different nonnormalized EST libraries of the domestic pig were analyzed. These EST libraries cover the nervous system, digestive system, immune system, and meat production related tissues from embryo, newborn, and adult pigs, making contributions to the analysis of alternative splicing variants as well as expression profiles in various stages of tissues. A modified approach was designed to cluster and assemble large EST datasets, aiming to detect alternative splicing together with EST abundance of each splicing variant. Much efforts were made to classify alternative splicing into different types and apply different filters to each type to get more reliable results. Finally, a total of 1,223 genes with average 2.8 splicing variants were detected among 16,540 unique genes. The overview of expression profiles would change when we take alternative splicing into account. 相似文献
24.
观察了喉返神经对大鼠血清甲状腺素水平和甲状腺摄碘功能的影响:(1)切断大鼠单侧喉返神经后血清甲状腺素(T4)水平升高,如于切断后立即电刺激其外周端,在30min内血清T4水平甚至降至对照值之下,事先给以阿托品,可阻断电刺激引起的效应。(2)切断单侧喉返神经后该侧甲状腺摄碘增多,以上结果表明,喉返神经抑制甲状腺素的分泌,这作用可能是由M受体介导调节的。 相似文献
25.
Verde F 《Current opinion in microbiology》1998,1(6):712-718
In the past year, we have gained considerable insight into the process of cell morphogenesis and the establishment of positional information in fission yeast. The highlights include a better understanding of the role of the microtubule cytoskeleton in the control of cell shape, as well as the identification of novel genes essential for the establishment of cell polarity and for the positioning of the site of cell division. 相似文献
26.
In Japan the most heavily cadmium (Cd)-polluted region is the Jinzu river basin, where Itai-itai disease is endemic and the Kakehashi river basin is the second most polluted region.. The village average Cd concentrations in rice were distributed in the range between 0.02 microg/g and 1.06 microg/g in the Jinzu river basin and 0.11 microg g and 0.67 microg g in the Kakehashi river basin. Severe renal damage has occurred widely in the Jinzu river basin. Even after Cd exposure had ceased, renal dysfunction became worse. Dose-response relationships between Cd exposure and health effects were clearly demonstrated in both regions. The allowable limits (according to the present authors' assessment) of Cd concentrations in rice were estimated to be 0.08 microg g to 0.13 microg g and approximately 2 g for total Cd intake. Renal dysfunction caused by exposure to Cd was associated with an increased mortality in both regions. The increased total Cd intake and high concentration of Cd in rice also exerts an adverse influence on life prognosis. 相似文献
27.
Sonar target strength measurements of several types of nets and associated gear were made using simulated dolphin echolocation signals. The different types of nets included (a) standard commercial monofilament gillnet used in the salmon mothership fishery, (b) prototype hollow core monofilament net, (c) Macah tribal cord setnet, and (d) multifilament nets. Target strength measurements were made at four angles of incidence, 0° (normal to net), 15°, 30°, and 45°. The standard gillnet had the smallest target strength which was relatively independent of the angle of incidence. The target strength based on the peak-to-peak values of the echoes varied from –59 to – 62 dB. Using echo energy within the integration time of Tursiops truncatus , the target strength was found to be between – 54 and –59 dB. Biosonar detection ranges for different sea state conditions were estimated using the noise-limited form of the sonar equation and target detection data obtained for Tursiops truncatus in Kaneohe Bay, Oahu, Hawaii. The results suggest that an echolocating dolphin should be able to detect a gillnet at ranges long enough to avoid entanglement, even in sea state 6 conditions. Several possibilities for the seeming inability of dolphins to detect gillnets are discussed. 相似文献
28.
Jesús M. Mercado F. L. Figueroa F. Xauier Niell Lennart Axelsson 《Journal of phycology》1997,33(6):999-1006
The effects of external carbonic anhydrase (CA, E.C. 4.2.1.1) on HCO?3and CO2use under disequilibnum conditions were examined in 14 species of macroalgae. CO2 was added to the algae in synthetic seawater free from inorganic carbon and buffered to pH 8.7. This resulted in a transient O2 evolution, which was similar for most of the species tested: an initial rapid increase in the rate was followed by a gradual decrease, approaching a steady state within 10 min. The initial high rate of O2evolution was attributed to diffusive entry of CO2into the cells and the steady state to use of HCO?3. An enhancement of CO2diffusive entry was obtained with acetazolamide, an inhibitor of external CA activity. Using this enhancement, a variable was developed to quantify the degree to which CO2entry into the cell was prevented by the external CA. This variable, CA (%), was used as a measure of the external CA activity of the alga. Comparative measurements of the external CA activity using a potentiomtric method revealed that the new method was able to detect low levels of external CA activity, where the potentiometric method failed. These two different methods could be used together to increase the reliability of the measurements. The new method was useful for red and brown macroalgae and for those green macroalgae that lacked direct HCO3uptake. Thus prominent external CA activity was found for Valonia utricularis (green), Halopteris scoparia (brown), and Osmunda pinnatifida (red), where the potentiometric method failed, or nearly failed, to indicate any external CA activity. Direct uptake of HCO?3interfered with the new method and the degree of this interference was dependent on the magnitude of the uptake. 相似文献
29.
30.
In fission yeast Schizosaccharomyces pombe , the directions of cell growth change from monopolar to bipolar in character, which is known as 'new end take off' (NETO). We previously found that arf6p, a member (class III) of the ADP-ribosylation factor (Arf) family, is necessary for NETO in fission yeast. Here we report the characterization of an S. pombe gene, syt22 + , encoding a putative Arf guanine nucleotide exchange factor (GEF). The syt22 protein contains a Sec7 domain and a PH domain conserved in the mammalian EFA6 GEF family, and has high similarity to Yel1p, which was identified as a GEF for Arf3p (class III Arf) in Saccharomyces cerevisiae. syt22 Δ cells, like arf6 Δ cells, completely failed to undergo NETO. Syt22p uniformly localizes to the cell periphery. Its localization is not dependent on microtubules, actin cytoskeletons or arf6p. We hypothesize that syt22p functions as a GEF for arf6p. 相似文献