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1.
The involvement of gibberellins in the control of flowering of sunflower was studied by direct application of GA3 to the apex of the plants, analysis of the endogenous levels of gibberellin-like substances at different plant ages, and indirectly by the application of paclobutrazol, an inhibitor of gibberellin synthesis. GA3 speeded-up flower initiation and floral apex development. The time of GA3 application was more critical than the amount of GA3 applied. The endogenous levels of gibberellin-like compounds increased significantly by day 15 after sowing. The application of paclobutrazol markedly delayed floral initiation and this effect was also depedent on plant age. Both GA3 and paclobutrazol had their greatest effects between 10 and 20 days after sowing suggesting that an increase in gibberellins in that time period plays a role in floral initiation. 相似文献
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E. Grotewold G. E. Taccioli G. O. Aisemberg N. D. Judewicz 《World journal of microbiology & biotechnology》1988,4(3):357-363
Summary A single-step purification procedure forNeurospora crassa laccase is reported. It used Celite chromatography which permits the concentration of the extracellular enzyme from large culture volumes. This method is useful to isolate any fungal or plant laccase as well as other coppercontaining proteins. This work also takes advantage of the 100-fold induction of the enzyme by low concentrations of cycloheximide.
Resumen Aquí se reporta un procedimiento de purificación en un solo paso para le enzima lacasa deNeurospora crassa. Consiste en el empleo de la cromatografía en Celite que permite la concentración de la enzima exocelular de grandes volúmenes de cultivo. Este método es útil para aislar cualquier lacasa de hongos o plantas así como otras proteínas que contienen sobre. En este trabajo, hemos aprovechado también la inducción de la enzima en más de 100 veces por bajas concentraciones de cicloheximida.
Résumé Nous rapportons ici une procédure de purification en une étape de la laccase deNeurospora crassa. Elle consiste à employer la chromatographie sur Celite qui permet la concentration de l'enzyme exo-cellulaire à partir de grands volumes de milieu de culture. Cette méthode permet d'isoler n'importe quelle laccase fungique ou de plante ainsi que d'autres protéines à cuivre. Dans le présent travail, nous avons aussi tiré parti de l'induction au centuple de l'enzyme par de faibles concentrations en cycloheximide.相似文献
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Andrea Lami Aldo Marchetto Piero Guilizzoni Anselma Giorgis Julieta Masaferro 《Hydrobiologia》1994,274(1-3):57-64
Stratigraphic analyses of organic carbon, organic nitrogen and algal and bacterial carotenoids in short cores of profundal
sediments of four alpine lakes (Tovel, Leit, Paione superiore and Tom) were used to reconstruct their trophic history. In
addition, depth distribution of carbonaceous particle concentrations provided information on lake contamination from atmospheric
deposition.
In three lakes (Tovel, Leit and Tom), sedimentary carotenoids unique to sulfur photosynthetic bacteria (okenone and isorenieratene)
provide evidence of changes in the oxygen, light and sulfide conditions in the water column. All the lakes are oligotrophic
or moderately productive, and the algal community is dominated by Chlorophyta, Pyrrhophyta and Cryptophyta. Cyanobacteria
are rather poorly represented.
The steep increase of carbonaceous particles in the uppermost sediment layers of all the lakes suggests that lake contamination
by atmospheric transport of pollutants began in the 1940s to 1950s. These data, coupled with those from a parallel study on
Chrysophycean scale-inferred pH, indicate recent acidification in those which are poorly buffered (Paione superiore and Leit). 相似文献
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Vélez Debora E. Mestre-Cordero Victoria E. Hermann Romina Perego Juliana Harriet Sofia Fernandez-Pazos María de las Mercedes Mourglia Julieta Marina-Prendes M. Gabriela 《Journal of physiology and biochemistry》2020,76(1):85-98
Journal of Physiology and Biochemistry - The cardioprotective activity of rosuvastatin (R) is yet to be known. The objective of this study was to research whether R perfusion before global ischemia... 相似文献
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Sandra Y. Valencia C Carlos A. Isaza M Julieta Henao B Leonardo Beltrán A Nelsy Loango Patricia Landázuri 《Biochemistry and Biophysics Reports》2021
BackgroundControversy exists regarding the role of the subfractions of high-density lipoproteins (HDL2 and HDL3) in cardiovascular disease. The functionality of these particles, and their protective role, is due in part to the paraoxonase 1 (PON1) presence in them. The polymorphisms rs662 (Q192R, A/G), rs854560 (L55 M, T/A), and rs705379 (C-108T) of the PON1 gene have been related to enzyme activity and, with the anti-oxidative capacity of the HDL. The objective was to determine the arylesterase PON1 activity in HDL3 and HDL2 and its relationship with the polymorphisms mentioned, in a young population.MethodsThe polymorphisms were determined through mini-sequencing (SnaPshot). The HDL subpopulations were separated via ionic precipitation, cholesterol was measured with enzymatic methods, and PON1 activity was measured through spectrophotometry.ResultsThe results show that the PON1 polymorphisms do not influence the cholesterol in the HDL. A variation between 40.02 and 43.9 mg/dL was in all the polymorphisms without significant differences. Additionally, PON1 activity in the HDL3 subfractions was greater (62.83 ± 20 kU/L) than with HDL2 (35.8 ± 20.8 kU/L) in the whole population and in all the polymorphisms (p < 0.001), and it was independent of the polymorphism and differential arylesterase activity in the Q192R polymorphism (QQ > QR > RR). Thus, 115.90 ± 30.7, 88.78 ± 21.3, 65.29 ± 10.2, respectively, for total HDL, with identical behavior for HDL3 and HDL2.ConclusionsPON1 polymorphisms do not influence the HDL-c, and the PON activity is greater in the HDL3 than in the HDL2, independent of the polymorphism, but it is necessary to delve into the functionality of these findings in different populations. 相似文献
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Francisco Cuesta Carolina Tovar Luis D. Llambí William D. Gosling Stephan Halloy Julieta Carilla Priscilla Muriel Rosa I. Meneses Stephan Beck Carmen Ulloa Ulloa Karina Yager Nikolay Aguirre Paul Viñas Jorge Jácome David Suárez-Duque Wouter Buytaert Harald Pauli 《Journal of Biogeography》2020,47(2):408-420
10.
Julieta Manrique Michael Piatak William Lauer Welkin Johnson Keith Mansfield Jeffrey Lifson Ronald Desrosiers 《Journal of virology》2013,87(13):7246-7254
Vaccine/challenge experiments that utilize live attenuated strains of simian immunodeficiency virus (SIV) in monkeys may be useful for elucidating what is needed from a vaccine in order to achieve protective immunity. Derivatives of SIVmac239 and SIVmac239Δnef were constructed in which env sequences were replaced with those of the heterologous strain E543; these were then used in vaccine/challenge experiments. When challenge occurred at 22 weeks, 10 of 12 monkeys exhibited apparent sterilizing immunity despite a mismatch of Env sequences, compared to 12 of 12 monkeys with apparent sterilizing immunity when challenge virus was matched in its Env sequence. However, when challenge occurred at 6 weeks, 6 of 6 SIV239Δnef-immunized monkeys became superinfected by challenge virus mismatched in its Env sequence (SIV239/EnvE543). These results contrast markedly not only with the results of the week 22 challenge but also with the sterilizing immunity observed in 5 of 5 SIV239Δnef-immunized rhesus monkeys challenged at 5 weeks with SIV239, i.e., with no mismatch of Env sequences. We conclude from these studies that a mismatch of Env sequences in the challenge virus can have a dramatic effect on the extent of apparent sterilizing immunity when challenge occurs relatively early, 5 to 6 weeks after the nef-deleted SIV administration. However, by 22 weeks, mismatch of Env sequences has little or no influence on the degree of protection against challenge virus. Our findings suggest that anti-Env immune responses are a key component of the protective immunity elicited by live attenuated, nef-deleted SIV. 相似文献