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1.
S. H. Habib S.-E. Ooi Ond?ej Novák Danu?e Tarkowská Jakub Rol?ík Karel Dole?al S. S. R. Syed-Alwee C.-L. Ho P. Namasivayam 《Plant Growth Regulation》2012,68(2):313-317
Comparative mineral and hormonal analyses were made on tissue culture derived truncated leaf syndrome and wild type oil palm seedlings. Mineral analysis confirmed that Boron, Zinc and chlorophyll levels were significantly lower in truncated leaf syndrome leaves than those of wild type. Hormonal analysis also revealed various cytokinin derivatives such as trans-zeatin, trans-zeatin riboside, trans-zeatin O-glucoside and trans-zeatin riboside 5??mono phosphate were significantly higher in truncated leaf syndrome leaves compared to wild type leaves. Brassinolide level was also significantly higher in truncated leaf syndrome leaves than those of the wild type. These observations suggest that the truncated leaf syndrome abnormality could be associated to high cytokinin and brassinosteroid production which affects the uptake of Boron and Zinc. 相似文献
2.
Five popular but iron-inefficient cultivars were crossed with three efficient genotypes and both parents and F1s were evaluated for iron-efficiency in potted calcareous and noncalcareous soil. The iron-efficient genotypes were dark green or green in both noncalcareous and calcareous soils whereas inefficient types were light green to yellow in calcareous soil. The chlorophyll and active iron (Fe2+) concentration of leaves was less in iron-efficient genotypes compared to efficient types in calcareous soil and reduction of both the parameters from noncalcareous to calcareous soil was considerably high in iron-inefficient lines. There was significant correlation between visual scores, chlorophyll and active iron content. There were no differences among F1s for iron chlorosis and they were all iron-inefficient. The frequency of iron-inefficient plants was higher than the efficient plants in all F2 populations. But most of the productive plants came from iron-efficient segregants indicating strong association between iron-efficiency and productivity. Based on the results selection for iron-efficiency in early generations and extensive evaluation for productivity in advanced generations is suggested for developing varieties for cultivation in calcareous soils. 相似文献
3.
A kinetic analysis of the 5 alpha-reductases from human liver and prostate is presented. Human prostatic 5 alpha-reductase follows an ordered sequential mechanism in which NADPH binds first followed by testosterone. The order of release of products is DHT followed by NADP+. The apparent Km of prostatic 5 alpha-reductase for testosterone is 0.0339 +/- 0.006 microM, while the apparent Km for NADPH is 2.52 +/- 0.65 microM. Human liver 5 alpha-reductase also follows a sequential mechanism. The apparent Km of the liver enzyme is 0.110 +/- 0.08 microM; the apparent Km for NADPH is 6.2 +/- 0.6 microM. The fact that both the liver and prostatic 5 alpha-reductases have a sequential kinetic mechanism rules out the possibility that the reduction of testosterone to dihydrotestosterone involves an electron transport system as previously proposed. 相似文献
4.
R. Habib 《Plant and Soil》1988,108(2):267-274
A method is proposed for estimating the total length of a root system from sub-samples. This method is based on the measurement
of the length and diameter of small pieces of roots, and on the measurements of the bulk density of root sub-samples. It is
assumed that roots are cylinders with a given bulk density. The length and diameter of small root pieces are measured by image
analysis. A weighted quadratic mean (W.Q.M.) root diameter is then calculated and used in estimating the root length. This
W.Q.M. diameter is defined as the real mean diameter of an equivalent single root with the same length and volume as the tested
root system. The accuracy of prediction is demonstrated for one theoretical root system. The standard deviation of estimation
can be calculated using sampling simulations. 相似文献
5.
Influence of maize root mucilage on soil aggregate stability 总被引:9,自引:0,他引:9
This study was undertaken to determine the effects of root exudates on soil aggregate stability. Root mucilage was collected
from two-month old maize plants (Zea mays L.) Mucilage and glucose solutions were added at a rate of 2.45 g C kg−1 dry soil to silty clay and silt loam soils. Amended soils, placed in serum flasks, were incubated for 42 d with a drying-wetting
cycle after 21 d. Evolved CO2 was measured periodically as well as the water-stable aggregates and soluble sugar and polysaccharide content of the soil.
In mucilage-amended soils CO2 evolution started with a lag phase of 2–3 days, which was not observed in glucose-amended soils. There was then a sharp increase
in evolved CO2 up to day 7. During the second incubation period there were only small differences in evolved C between treatments. Incorporation
of mucilage in both soils resulted in a spectacular and immediate increase in soil aggregate stability. Thereafter, the percent
of water-stable aggregates quickly decreased parallel to microbial degradation. On completion of the incubation, aggregate
stability in the silty clay soil was still significantly higher in the presence of mucilage than in the control. This work
supports the assumption that freshly released mucilage is able to stick very rapidly to soil particles and may protect the
newly formed aggregates against water destruction. On the silty clay, microbial activity contributes to a stabilization of
these established organo-mineral bounds. 相似文献
6.
N Habib 《BMJ (Clinical research ed.)》1972,2(5806):166-167
7.
8.
Iris M Costa Tallybia HT Nasser Marilene Demasi Rafaella MP Nascimento Luis ES Netto Sayuri Miyamoto Fernanda M Prado Gisele Monteiro 《BMC microbiology》2011,11(1):268
Background
The gene YCL047C, which has been renamed promoter of filamentation gene (POF1), has recently been described as a cell component involved in yeast filamentous growth. The objective of this work is to understand the molecular and biological function of this gene.Results
Here, we report that the protein encoded by the POF1 gene, Pof1p, is an ATPase that may be part of the Saccharomyces cerevisiae protein quality control pathway. According to the results, Δpof1 cells showed increased sensitivity to hydrogen peroxide, tert-butyl hydroperoxide, heat shock and protein unfolding agents, such as dithiothreitol and tunicamycin. Besides, the overexpression of POF1 suppressed the sensitivity of Δpct1, a strain that lacks a gene that encodes a phosphocholine cytidylyltransferase, to heat shock. In vitro analysis showed, however, that the purified Pof1p enzyme had no cytidylyltransferase activity but does have ATPase activity, with catalytic efficiency comparable to other ATPases involved in endoplasmic reticulum-associated degradation of proteins (ERAD). Supporting these findings, co-immunoprecipitation experiments showed a physical interaction between Pof1p and Ubc7p (an ubiquitin conjugating enzyme) in vivo.Conclusions
Taken together, the results strongly suggest that the biological function of Pof1p is related to the regulation of protein degradation.9.
The gene encoding the extracellular lipase of Staphylococcus xylosus (SXL) was cloned using PCR technique. The sequence corresponding to the mature lipase was subcloned in the pET-14b expression vector, with a strong T7 promoter, to construct a recombinant lipase protein containing six histidine residues at the N-terminal. High level expression of the lipase by Escherichia coli BL21 (DE3) cells harbouring the lipase gene containing expression vector was observed upon induction with 0.4 mM IPTG at 37 degrees C. One-step purification of the recombinant lipase was achieved with Ni-NTA resin. The specific activity of the purified His-tagged SXL was 1500 or 850 U/mg using tributyrin or olive oil emulsion as substrate, respectively. It has been proposed that the region near the residue Asp290 could be involved in the selection of the substrate. Therefore, we also mutated the residue Asp 290 by Ala using site-directed mutagenesis. The mutant SXL-D290A was overexpressed in E. coli BL21 (DE3) and purified with the same nickel metal affinity column. The specific activity of the purified His-tagged SXL-D290A mutant was 1000 U/mg using either tributyrin or olive oil emulsion as substrate. A comparative study of the wild type (His(6)-SXL) and the mutant (His(6)-SXL-D290A) proteins was carried out. Our results confirmed that Asp290 is important for the chain length specificity and catalytic efficiency of the enzyme. 相似文献
10.
<Emphasis Type="Italic">Actinoplanes deserti</Emphasis> sp. nov., isolated from a desert soil sample
Neeli Habib Inam Ullah Khan Xiao Chu Min Xiao Shuai Li Bao-Zhu Fang Xiao-Yang Zhi Wen-Jun Li 《Antonie van Leeuwenhoek》2018,111(12):2303-2310
A novel actinomycete, designated strain YIM CF22T, was isolated from a desert soil sample collected from Turpan in Xinjiang Uyghur Autonomous Region, north-western China. The taxonomic position of the strain YIM CF22T is described based on a polyphasic approach. Strain YIM CF22T was found to form irregular sporangia on agar media. It contains meso-diaminopimelic acid in the cell wall peptidoglycan. The major menaquinone was identified as MK-9(H4); the polar lipids were identified as diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, two unidentified phospholipids and two unidentified glycolipids. The whole cell sugars were found to be ribose, mannose, galactose, glucose and xylose. The major cellular fatty acids were found to be (>?5%) iso-C16:0 (43.5%), anteiso-C17:0 (10.2%), iso-C15:0 (7.1%), C17:1 ω8c (6.3%) and iso H-C16:1 (5.9%). The G+C content was determined to be 70.8%. 16S rRNA gene sequence analysis of strain YIM CF22T showed high similarity (97.0%) to Actinoplanes rishiriensis NBRC 108556T. The strain also showed high 16S rRNA gene sequence similarities to Verrucosispora sediminis CGMCC 4.3550T (96.9%) and Micromonospora tulbaghiae DSM 45142T (96.8%). Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain YIM CF22T clusters with A. rishiriensis NBRC 108556T, Actinoplanes globisporus JCM 3186T and Actinoplanes rhizophilus NEAU-A-2T. Based on the differential phenotypic characteristics and the results of DNA–DNA relatedness and phylogenetic analysis, it is proposed that strain YIM CF22T represents a novel species of the genus Actinoplanes, for which the name Actinoplanes deserti sp. nov. is proposed. The type strain is YIM CF22T (=?KCTC 39543T?=?CCTCC AB2018113T). 相似文献