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121.
Mare K. Saba-El-Leil Sylvain Rivard David Morse Mario Cappadocia 《Plant molecular biology》1994,24(4):571-583
A genomic clone of the S11 allele from the self-incompatibility locus (S locus) in Solanum chacoense Bitt. has been isolated by cross-hybridization to the S. chacoense S13 allele and sequenced. The sequence of the S11 allele contains all the features expected for S genes of the Solanaceae, and S11 expression, as assessed by northern blots and RNA-PCR, was similar to that of other S. chacoense S alleles. The S11 protein sequence shares 95% identity with the phenotypically distinct S13 protein of S. chacoense and is the gametophytic S allele with the highest similarity to an existing allele so far discovered. Only 10 amino acid changes differentiate the mature proteins from these two alleles, which sets a new lower limit to the number of changes that can produce an altered S allele specificity. The amino acid substitutions are not clustered, suggesting that an accumulation of random point mutations can generate S allele diversity. The S11 intron is unusual in that it could be translated in frame with the coding sequence, thus suggesting an additional mechanism for the generation of new S alleles. 相似文献
122.
Piero Picciarelli Alberto Piaggesi Nello Ceccarelli Lorenzo Guglielminetti Amedeo Alpi 《Plant Growth Regulation》1994,14(2):183-185
Endogenous gibberellins (GAs) were extracted from suspensor, embryo and integument of very young seeds of Phaseolus coccineus L. and detected by combined gas chromatography-mass spectrometry (GC-MS). Results show the presence of one C20-GA, GA44 and five C19-GAs in the suspensor: GA1, GA4, GA5, GA6 and GA8, and four C19-GAs in the integument: GA1, GA5, GA6 and GA8. Only traces of GA1 and GA5 were identified in the embryo. A compound structurally related to GAs was identified as tetrahydroxy-Kauranoic acid in suspensor, integument and, only in trace amounts, in the embryo. 相似文献
123.
Raquel Fernández-Durango José A. de Juan Horatio Zimman Francisco J. Moya Mario Garcia de la Coba Arturo Fernández-Cruz 《Journal of neurochemistry》1994,62(4):1482-1488
Abstract: Specific endothelin (ET) binding sites were characterized in membranes prepared from human cerebral cortices using binding assay and cross-linking analysis. The presence of immunoreactive (IR) ET-1 was studied by radioimmunoassay. Saturation binding experiments revealed that the K D and B max for 125 I-ET-1 and 125 l-ET-3 to membranes from gray matter were 25 ± 6 pM and 115 ± 15 fmol/mg of protein and 24 ± 5 p M and 108 ± 13 fmol/mg of protein, respectively. Similar results were obtained for white matter. In the presence of 10 n M sarafotoxin-6c, which is selective for ETB receptors, 125 I-ET-1 and 125 l-ET-3 binding was totally abolished. However, in the presence of 1 μ M BQ123, which is selective for ETA receptors, both bindings were not affected. These results suggest that the human cerebral cortex contains only ETB receptors. Cross-linking of 125 I-ET-1 and 125 l-ET-3 to membranes with disuccinimidyl suberate resulted in the labeling of two bands of 48 and 31 kDa. Concentrations of IR-ET-1 in the gray and white matter were 7.0 ± 3.2 and 2.5 ± 1.7 fmol/g wet weight, respectively. The demonstration of high-affinity ETB receptors and the presence of IRET-1 suggest that the peptide may act as a neurotransmitter or neuromodulator in the human cerebral cortex. 相似文献
124.
ABA and Low Temperature Induce Freezing Tolerance via Distinct Regulatory Pathways in Wheat 总被引:1,自引:0,他引:1
Dallaire Sylvain; Houde Mario; Gagne Yves; Saini Hargurdeep S.; Boileau Serge; Chevrier Normand; Sarhan Fathey 《Plant & cell physiology》1994,35(1):1-9
The role of ABA in the induction of freezing tolerance was investigatedin two wheat (T. aestivum L.) cultivars, Glenlea (spring var)and Fredrick (winter var). Exogenous application of ABA (5x105M for 5 days at 24°C) increased the freezing tolerance ofintact plants by only 3°C (LT50) in both cultivars. Maximalfreezing tolerance (LT50 of 9°C for Glenlea and 17°Cfor Fredrick) could only be obtained with a low temperaturetreatment (6/2°C; day/night) for 40 days. These resultsshow that exogenously applied ABA cannot substitute for lowtemperature requirementto induce freezing tolerance in intactwheat plants. Furthermore, there was no increase in the endogenousABA level of wheat plants during low temperature acclimation,suggesting the absence of an essential role for ABA in the developmentof freezing tolerance in intact plants. On the other hand, ABAapplication (5x105 M for 5 days at 24°C) to embryogenicwheat calli resulted in an increase of freezing tolerance similarto that achieved by low temperature. However, as in intact plants,there was no increase in the endogenous ABA level during lowtemperature acclimation of calli. These results indicate thatthe induction of freezing tolerance by low temperature is notassociated with an increase in ABA content. Using an antibodyspecific to a protein family associated with the developmentof freezing tolerance, we demonstrated that the induction offreezing tolerance by ABA in embryogenic wheat calli was correlatedwith the accumulation of a new 32 kDa protein. This proteinis specifically induced by ABA but shares a common antigenicitywith those induced by low temperature. These results suggestthat ABA induces freezing tolerance in wheat calli via a regulatorymechanism different from that of low temperature. (Received June 15, 1993; Accepted September 16, 1993) 相似文献
125.
126.
Acetaldehyde production in Saccharomyces cerevisiae wine yeasts 总被引:1,自引:0,他引:1
Patrizia Romano Giovanna Suzzi Luca Turbanti Mario Polsinelli 《FEMS microbiology letters》1994,118(3):213-218
Abstract Eighty-six strains of Saccharomyces cerevisiae were investigated for their ability to produce acetaldehyde in synthetic medium and in grape must. Acetaldehyde production did not differ significantly between the two media, ranging from a few mg/l to about 60 mg/l, and was found to be a strain characteristic. The fermentation temperature of 30°C considerably increased the acetaldehyde produced. This study allowed us to assign the strains to different phenotypes: low, medium and high acetaldehyde producers. The low and high phenotypes differed considerably also in the production of acetic acid, acetoin and higher alcohols and can be useful for studying acetaldehyde production in S. cerevisiae , both from the technological and genetic point of view. 相似文献
127.
Mario Herrera-Marschitz C. Fabián Loidl Zhi-Bing You Kurt Andersson Rodolfo Silveira William T. O'Connor Michel Goiny 《Molecular neurobiology》1994,9(1-3):171-182
The neurocircuitries of the basal ganglia are studied with in vivo microdialysis, with special consideration to dopamine transmission and its interaction with other neurotransmitter systems. The aim is to develop experimental models to study the pathophysiology and therapy of neurodegenerative disorders of the basal ganglia, as well as to develop models to study the short- and long-term consequences of perinatal asphyctic lesions. A main goal of these studies is to find and to characterize new treatments for these disorders. 相似文献
128.
Alberto A. Iglesias William C. Plaxton Florencio E. Podestá 《Photosynthesis research》1993,35(3):205-211
Inorganic phosphate participates in many fundamental processes within the plant cell. Its broad influence on plant metabolism is related to such key operations as metabolite transport, enzyme regulation and carbohydrate metabolism in general. This review discusses these topics with special emphasis on the role assigned to this ubiquitous anion within the C4 pathway of photosynthesis.Abbreviations DHAP
dihydroxyacetone phosphate
- Ga3P
glyceraldehyde-3-phosphate
- NAD(P)-ME-NAD(P)
dependent malic enzyme
- PEP
phosphoenolpyruvate
- 3-PGA
3-phosphoglycerate
- PFK and PFP-ATP- and PPi
dependent fructose-6-phosphate 1-phosphotransferase
- PPDK
pyruvate:orthophosphate dikinase
- RPPC
reductive pentose-phosphate cycle
- RuBisCO
ribulose bisphosphate carboxylase-oxygenase
- SPS
sucrose-6-phosphate synthase 相似文献
129.
130.
Peter E. Andreotti Dee Linder Diana M. Hartmann Ian A. Cree Mario Pazzagli Howard W. Bruckner 《Luminescence》1994,9(6):373-378
The BATLE LE TCA-100 tumour chemosensitivity assay has been used to evaluate chemotherapeutic drug sensitivity of cultured tumour cell lines. Studies were performed using test drug concentrations calibrated to discriminate sensitivity and resistance of clinical specimens. Strong sensitivity which appeared to be inconsistent with clinical experience was detected for some drugs and cell lines. Findings of strong sensitivity were consistent with basic differences between sensitivity testing cultured cell lines and clinical specimens. Results with cell lines frequently may not apply directly to clinical applications. Characterization of differences between cell lines and clinical specimens may assist in application of cell line findings to clinical trials. 相似文献