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41.
William K. Vencill Kriton K. Hatzios Henry P. Wilson 《Journal of Plant Growth Regulation》1990,9(1-3):127-132
The patterns of clomazone (2-[(2-chlorophenyl) methyl-4,4-dimethyl-3-isoxazolidinone) absorption, translocation, and metabolism and their contribution to the plant selectivity of this herbicide were studied in tolerant soybean [Glycine max (L.) Merr.] andAmaranthus hybridus and in susceptibleA. retroflexus andA. lividus. Differential root absorption appeared to play a significant role in the differential response of these four plant species to clomazone. Absorption of root-applied14C-clomazone was greater by the two sensitiveAmaranthus weeds than by the tolerant soybean andA. hybri-dus. Following application of14C-clomazone to roots, most of the absorbed radioactivity was translocated to the leaves of all four species. Approximately 50% of the absorbed14C-clomazone was metabolized by all four plant species as early as 12 h after treatment. Thin layer Chromatographic (TLC) analysis of plant tissue extracts from all four species revealed the formation of two major metabolites of clomazone. These unidentified metabolites had Rf values of 0.4 and 0.8, respectively, in a butanolacetic acidwater (1235, vol/vol/vol) developing system. The Rf value of unaltered clomazone in this system was 0.95. Differential metabolism or differential rate of metabolism of clomazone was not observed in this study and did not seem to account for the tolerance of soybean andA. hybridus or the suceptibility ofA. retroflexus andA. lividus to this herbicide.Plant Pathology, Physiology, and Weed Science Department, Contribution No. 600. 相似文献
42.
Abstract The infection frequency of both compatible and incompatible races of Erysiphe graminis f. sp. hordei decreased gradually with increasing leaf age on undetached primary barley leaves. The length of secondary hyphae of the compatible race was approximately the same regardless of age, but secondary hyphae were slightly longer on younger seedlings than on older seedlings in the case of the incompatible race. Both the infection frequency and length of secondary hyphae of the two races weredistinctly different. On composite sections produced by exchanging the epidermal layers of young and relatively mature primary leaves, the infection frequency of the compatible race was higher on the epidermis of young leaves than on the epidermis of older, leaves, regardless of which mesophyll was under the epidermis. The epidermis appears to play a major role in age-dependent resistance, while the mesophyll may act disparately by providing a factor promotive to mildew infection in addition to supporting the resistance function of the epidermis. 相似文献
43.
44.
A synchronization treatment was initiated when each of 1227 heifers (four trials) was tailpainted. The tailpaint was sprayed with an aerosol raddle at the end of the treatment period. The heifers were in herds of 20 to 279 animals. Each herd was observed for estrus at selected post treatment intervals. A heifer was considered to be (or to have been) in estrus when the raddle was rubbed off. In three of the trials, animals which had the raddle removed were inseminated at 48h following the end of the synchronization treatment. The tailpaint of an inseminated animal was scored from 0 (less than 10% of the paint remained) to 5 (more than 90% of the paint remained) and was then reraddled with a second color. The detection-insemination sequence was always repeated at 72 and 96h, and sometimes at 120h. Animals which had been previously inseminated, but then had paint scores reduced by at least 2 units were reinseminated 24h later. Over the four trials, 94.5% of the heifers were detected in estrus through the use of the tailpaint and raddle system. The remaining 67 animals included only 10 (0.8%) which had ovulated without being detected in estrus. The reinsemination rate on consecutive days was 11.3% and was highest among animals that had a tailpaint score of 4 or 5 at 48h. The proportion of animals detected in estrus at selected posttreatment intervals varied with the different synchronization treatments used within one herd, or with the same treatment used in different herds. The combination of tailpaint, raddling, tailpaint scoring and reraddling is a simple sequence which can be effectively used to detect estrus among heifers synchronized in research or commercial herds. 相似文献
45.
A. Benslimane C. Hartmann J. de Buyse Y. Henry E. Picard A. Rode 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1988,75(3):389-396
Summary Restriction fragment length polymorphism of the wheat nuclear ribosomal DNA has been studied in several steps of a breeding scheme, including parental genotypes, F1 hybrid, F9 generation, and anther-derived doubled haploid lines obtained from F9. Ribosomal DNA represents a suitable molecular marker in following segregation and possible divergency from expected homozygosity after haploidization of an androgenetic process. It has been shown to undergo variations among the first cycle-doubled haploid lines in the relative amount of two different sizes of ribosomal DNA repeat units. The specificity and peculiar properties of the plant system used allowed us to assign an intrachromosomal location (short arm of the chromosomes 1B, 1R or 6B) to several ribosomal DNA repeat units that differ by the length of their nontranscribed spacer region. 相似文献
46.
C Moussard D Alber J C Henry 《Prostaglandins, leukotrienes, and essential fatty acids》1988,31(1):31-39
In an attempt to elucidate the possible involvements of eicosanoids in esophageal functions and disorders, we have investigated the formation of both cyclooxygenase and lipoxygenase metabolites from 14C-arachidonic acid by rabbit esophageal tissues. Homogenates of rabbit esophageal mucosa and muscularis were incubated with 14C-arachidonic acid and after ether extraction eicosanoids were separated and quantified by reverse phase high performance liquid chromatography. The predominant cyclooxygenase products were 6-keto-PGF1 alpha, PGF2 alpha, and PGE2 for mucosa and 6-keto-PGF1 alpha, and PGE2 for muscularis. The formation of these products was inhibited both by indomethacin and the dual pathway inhibitor, nordihydrogualaretic acid (NDGA). In mucosa the major eicosanoid was 12-HETE (12-hydroxyeicosatetraenoic acid) which was inhibited by NDGA but not by indomethacin which on the contrary enhanced its formation. Additionally four polar products were synthesized which appeared to be lipoxygenase-dependent as their formation was inhibited by NDGA but not by indomethacin. Muscularis produced as a minor lipoxygenase product only 12-HETE, which was inhibited by NDGA but unchanged in the presence of indomethacin. In addition, both tissues, but mucosa more than muscularis, possessed large prostaglandin catabolizing capacity. The present findings indicate that rabbit esophageal tissues can convert 14C-arachidonic acid into lipoxygenase as well cyclo-oxygenase products which may have a role in esophageal physiology and pathophysiology. 相似文献
47.
Maria F. S. Barbosa Maria B. de Medeiros Ismael M. de Mancilha Henry Schneider Hung Lee Ph.D. 《Journal of industrial microbiology & biotechnology》1988,3(4):241-251
Summary The ability to convertd-xylose to xylitol was screened in 44 yeasts from five genera. All but two of the strains produced some xylitol with varying rates and yields. The best xylitol producers were localized largely in the speciesCandida guilliermondii andC. tropicalis. Factors affecting xylitol production by a selectedC. guilliermondii strain, FTI-20037, were investigated. The results showed that xylitol yield by this strain was affected by the nitrogen source. Yield was highest at 30–35°C, and could be increased with decreasing aeration rate. Using high cell density and a defined medium under aerobic conditions, xylitol yield byC. guilliermondii FTI-20037 from 104 g/ld-xylose was found to be 77.2 g/l. This represented a yield of 81% of the theoretical value, which was computed to be 0.9 mol xylitol per mold-xylose.Issued as NRCC publication No. 28798. 相似文献
48.
Brain Cell Biology - Light and electron microscopy were used to investigate long-term regeneration in peripheral nerves regenerating across a 10 mm gap through silicone tubes. Schwann cells and... 相似文献
49.
Toshihiro Mitaka Gerald L. Sattler Henry C. Pitot Yohichi Mochizuki 《Virchows Archiv. B, Cell pathology including molecular pathology》1992,62(1):329-335
Phenotypes of the cells developing into small colonies after days of primary culture of adult rat hepatocytes in serum-free
modified Dulbecco Modified Eagles’ medium containing 10 mM nicotinamide and 10 ng/ml epidermal growth factor were analyzed
immunocytochemically, cytochemically and ultrastructurally. Albumin, cytokeratin 8 and 18 were seen by immunocytochemical
techniques in the cells of the small colonies at Day 6. Transferrin, α-antitrypsin, ceruloplasmin, and haptoglobin, proteins
secreted by mature hepatocytes, were faintly stained in these cells as was α-fetoprotein. These proteins were secreted into
the culture medium as evidenced by immunoblot analysis. γ-Glutamyltransferase, alkaline phosphatase and glucose 6-phosphatase
were not present in the cells of the small colonies as well as the surrounding hepatocytes at Day 6 of culture. In addition,
ultrastructural examinations of the cells in the small colonies indicated that these cells not only had many characteristic
mitochondria and desmosomes, but also a few small peroxisomes. Such cells, even after 20 days in culture were proliferating,
as evidenced by the intranuclear presence of the proliferating cell nuclear antigen. The potential relation of these cells
to hepatocytes which may serve as the principal reserve for replicating hepatocytes is discussed. 相似文献
50.
The NADP+-specific glutamate dehydrogenase (GDH) fromEscherichia coli strain D5H3G7, an enzyme that catalyzes the interconversion of -ketoglutarate andl-glutamate, has been shown to be phosphorylated in vitro in an ATP-dependent enzymatic reaction. The phosphorylated protein is extremely acid labile and is unstable at high pH. Treatment of GDH with diethyl pyrocarbonate (DEP), a histidine-modifying reagent, blocked the incorporation of32P from [-32P]ATP. GDH catalytic activity was also inhibited by DEP treatment. Hydroxylamine, a reagent hydrolyzing phosphoramidates, catalyzed the removal of phosphate from phosphorylated GDH, suggesting that GDH may be phosphorylated at a histidine residue(s). A total enzymatic hydrolysis of phosphorylated GDH, which was electroeluted from a native polyacrylamide gel, was analyzed by a Dowex 1-8X anion exchange chromatography. The presence of32P-labeled 3-phosphohistidine, characterized and identified from this hydrolysate, demonstrates that a histidine residue(s) is the site of phosphorylation. 相似文献