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911.
Alteration of nutrient allocation and transporter genes expression in rice under N,P, K,and Mg deficiencies 总被引:2,自引:0,他引:2
Jin?Cai Lu?Chen Hongye?Qu Juan?Lian Wei?Liu Yibing?Hu Guohua?XuEmail author 《Acta Physiologiae Plantarum》2012,34(3):939-946
Nitrogen (N), phosphorus (P), potassium (K), and magnesium (Mg) have essential physiological functions in plants. Their interactions
in plants are not fully understood especially at the molecular level. In this study, we detected the physiological and molecular
responses of rice plants at the vegetative growth phase to N, P, K, and Mg starvations. Deficiencies of N and P resulted in
accumulation of soluble sugar and starch in the leaves. The root to shoot ratio increased under N and P deficiencies, but
decreased under K and Mg deficiencies. In addition, deficiency of either K or Mg resulted in accumulation of the other cation
in shoots. Moreover, K starvation decreased both K and soluble sugar contents in the roots pronouncedly. RT-PCR analysis showed
that several sugar transporter genes in the leaves orchestrated with sugar accumulation induced by the nutrient shortages.
Expression of a high affinity K transporter gene (OsHAK1) and a putative Mg transporter gene (OsMGT) showed opposite down- and up-regulation in the roots by K starvation. These findings suggest that deficiencies of the major
nutrients suppressed the export of carbohydrates from source leaves. The regulated sugar and nutrient transporter genes investigated
in this study could be used for elucidating the molecular mechanism of plants in their adaptation to varied nutrient supply. 相似文献
912.
Two acidic polysaccharide fractions (PTPa and PTPb) extracted from the roots of Polygala tenuifolia, were obtained by DEAE-Sephacel anion-exchange, and Sephadex G-100 gel-permeation chromatography. High-performance liquid chromatography (HPLC) identified that PTPa and PTPb was composed of Ara, Glc, Gal, Man and GlcUA in the proportion of 2.4:1.2:0.6:0.4:1.1 and 2.1:1.7:0.5:0.6:1.7, respectively. Their molecular weight was evaluated to be 5.9×10(4) (PTPa) and 2.5×10(4)Da (PTPb) as determined by high performance size exclusion chromatography (HPSEC). Pharmacological studies revealed PTPa and PTPb significantly inhibited the growth of A549 cells in vitro and exhibited significantly higher antitumor activity against solid tumor A549 in vivo than did a blank control. Moreover, treatment with two acidic polysaccharides caused an enhancement of superoxide dismutase (SOD) and catalase (CAT) activities in tumor-bearing mice and a reduction in thiobarbituric acid reactive substances (TBARS) level. Taken together, these results indicated that two acidic polysaccharides from the roots of P. tenuifolia may be useful as potent antitumor agents for the prevention of lung tumorigenesis. 相似文献
913.
Zhu B Liu H Tian WX Fan XY Li B Zhou XP Jin GL Xie GL 《Journal of bacteriology》2012,194(5):1280-1281
Stenotrophomonas maltophilia is an endophyte which plays important roles in agricultural production as a plant growth-promoting bacterium. Here, we present the draft genome sequence of strain RR-10, which was isolated from a rice root in a rice field of China. 相似文献
914.
Shin SH Kim S Kim JY Song HY Cho SJ Kim DR Lee KI Lim HK Park NJ Hwang IT Yang KS 《Journal of bacteriology》2012,194(5):1266
This article reports on the full genome sequence of Paenibacillus terrae HPL-003, which is a gram-positive, endospore-forming, xylanase-producing bacterium isolated from soil found in forest residue on Gara Mountain. The strain HPL-003 contains 6,083,395 bp with a G+C content of 46.77 mol%, 2,633 protein-coding genes, and 117 structural RNAs. 相似文献
915.
916.
Kim AJ Choi JN Kim J Yeo SH Choi JH Lee CH 《Bioscience, biotechnology, and biochemistry》2012,76(5):863-869
The present study was focused on improving the quality of rice koji by fermentation with a selected Aspergillus oryzae strain and a plant Astragalus radix. A. oryzae KCCM 60345 was used as main inoculant and the Astragalus radix was added as supplement in rice koji preparation. LC-MS based metabolite analysis and tyrosinase inhibitory activities were studied for different time periods. A. oryzae KCCM 60345 fermented rice koji supplemented with Astragalus showed higher tyrosinase inhibition activity at 4 d of fermentation and metabolite analysis with PCA and PLS-DA indicated differences in kojic acid, calycosin-7-O-β-D-glucoside, ononin, calycosin, and formononetin as compared with other forms of rice koji fermentation. By correlation analysis between metabolites and tyrosinase inhibitory activity, calycosin and kojic acid were identified as major tyrosinase inhibitors. Based on these results, we concluded that A. oryzae KCCM 60345 supplemented with Astragalus radix is useful for whitening effects, and we identified optimal conditions for rice koji preparation. 相似文献
917.
918.
Light microscopic imaging of blood vessels and distribution of serum proteins is essential to analyze hemodynamics in living
animal lungs under normal respiration or respiratory diseases. In this study, to demonstrate dynamically changing morphology
and immunohistochemical images of their living states, “in vivo cryotechnique” (IVCT) combined with freeze-substitution fixation
was applied to anesthetized mouse lungs. By hematoxylin–eosin staining, morphological features, such as shapes of alveolar
septum and sizes of alveolar lumen, reflected their respiratory conditions in vivo, and alveolar capillaries were filled with
variously shaped erythrocytes. Albumin was usually immunolocalized in the capillaries, which was confirmed by double-immunostaining
for aquaporin-1 of endothelium. To capture accurate time-courses of blood flow in peripheral pulmonary alveoli, glutathione-coated
quantum dots (QDs) were injected into right ventricles, and then IVCT was performed at different time-points after the QD
injection. QDs were localized in most arterioles and some alveolar capillaries at 1 s, and later in venules at 2 s, reflecting
a typical blood flow direction in vivo. Three-dimensional QD images of microvascular networks were reconstructed by confocal
laser scanning microscopy. It was also applied to lungs of acute pulmonary hypertension mouse model. Erythrocytes were crammed
in blood vessels, and some serum components leaked into alveolar lumens, as confirmed by mouse albumin immunostaining. Some
separated collagen fibers and connecting elastic fibers were still detected in edematous tunica adventitia near terminal bronchioles.
Thus, IVCT combined with histochemical approaches enabled us to capture native images of dynamically changing structures and
microvascular hemodynamics of living mouse lungs. 相似文献
919.
Shi J Zhang H Snyder A Wang MX Xie J Marshall Porterfield D Stanciu LA 《Biosensors & bioelectronics》2012,38(1):314-320
The combination of Pt nanoparticles and graphene was more effective in enhancing biosensing than either nanomaterial alone according to previous reports. Based on the structural similarities between water soluble graphene oxide (GrO(x)) and graphene, we report the fabrication of an aqueous media based GrO(x)/Pt-black nanocomposite for biosensing enhancement. In this approach GrO(x) acted as a nanoscale molecular template for the electrodeposition of Pt-black, an amorphously nanopatterned isoform of platinum metal. Scanning electron microscopy (SEM) images and energy-dispersive X-ray spectroscopy (EDS) showed that Pt-black was growing along GrO(x). The effective surface area and electrocatalytic activity towards H(2)O(2) oxidation of GrO(x)/Pt-black microelectrodes were significantly higher than for Pt-black microelectrodes. When used to prepare a bio-nanocomposite based on protein functionalization with the enzyme glucose oxidase (GOx), the GrO(x)/Pt-black microbiosensors exhibited improved sensitivity over the Pt-black microbiosensors. This suggested that the GrO(x)/Pt-black nanocomposite facilitated an increase in electron transfer, and/or minimized mass transport limitations as compared to Pt-black used alone. Glucose microbiosensors based on GrO(x)/Pt-black exhibited high sensitivity (465.9±48.0nA/mM), a low detection limit of 1μM, a linear response range of 1μM-2mM, and response time of ~4s. Additionally the sensor was stable and highly selective over potential interferents. 相似文献
920.
Proteins in human serum are increasingly being studied for their roles in a wide variety of biochemical interactions. To improve the sensitivity of the detection of human serum proteins after native polyacrylamide gel electrophoresis (PAGE), we have developed a fluorescence imaging detection technique for the detection. BSA (bovine serum albumin)-stabilized Au nanoclusters (NCs) were applied as fluorescent probes for imaging, and low-temperature plasma (LTP) treatment of the Au NCs was introduced to enhance the fluorescence imaging. Here, a series of optimization experiments (e.g. those to optimize for pH) were conducted for protein detection after 1-DE and 2-DE, and several types of discharge gases (He, O(2), and N(2)) were selected for the LTP treatment. The possible mechanism of interaction between the proteins and the Au NCs was demonstrated by an isothermal titration calorimetry experiment. Using the present method, a sensitivity of 7-14 times higher than that of traditional staining detection methods was observed in the oxygen LTP-treated Au NCs fluorescence images, and some relatively low abundance proteins (identified by the MS/MS technique) were easily detected. In addition, this fluorescence imaging method was applied to distinguish between the serum samples of patients with liver diseases and those of healthy people. Thus, this fluorescence imaging method is suitable for the highly sensitive detection of various serum proteins, and it shows potential capabilities for clinical diagnosis. 相似文献