Effect Of Temperature Pretreatment Research Articles

Effects of temperature pretreatments and carbohydrate type on androgenesis induction in anther culture of Capparis spinosa L.

Caper (Capparis spinosa L.) is a rich source of rutin, plays an essential role in human health. In the present study, the effects of cold (25°C as control, 4°C, and 7°C for 2, 4, and 7 days), heat (25°C as control, 30°C for 14 days, 32°C for 2 and 4 days, and 35°C for 8 hours), and carbohydrate treatments on the androgenesis efficiency were studied in the anther culture of caper. Also, the effects of maltose and sucrose at the concentrations of 30 and 60 g L-1 in combination with two temperature treatments (1- 30°C for 14 days and 2- 7°C for 7 days + azacytidine and 2,4-D pretreatments) on the androgenesis induction was evaluated. The temperature and carbohydrate treatments showed statistically significant differences (p ≤0.01) in terms of callus and embryo formation. The 7°C for 2, 4, and 7 days produced the highest percentage (at the third week: 80, 78.34, and 76.67%, respectively) and callogenesis speed (7.85, 7.75, and 7.60 calli week-1, respectively) and the 7°C for 7 days produced the highest embryo production (0.57 embryo anther-1). The 30°C for 14 days treatment showed the highest percentage (at the third week: 100%) and callogenesis speed (9.44 calli week-1). While the 32°C for 2 and 3 days and also 30°C for 14 days produced the highest number of embryos per anther (0.22, 0.20, and 0.18 embryo, respectively). The use of 30 g L-1 maltose in combination with the 30°C for 14 days produced the highest percentage (at the third week: 91.66%) and callogenesis speed (8.94 calli week-1), while the 30 g L-1 maltose in combination with the 7°C for 7 days + azacytidine and 2,4-D pretreatments produced the highest mean embryo number per anther (0.55 embryo). The results of this research are of great importance for the use in the caper breeding programs.

Application of FTIR Spectroscopy to Analyze RNA Structure.

Fourier transform infrared (FTIR) spectroscopy has been widely used for the analysis of both protein and nucleic acid secondary structure. This is one of the vibration spectroscopy methods that are extremely sensitive to any change in molecular structure. While numerous reports describe how to proceed to analyze protein and deoxyribonucleic acid (DNA) structures using FTIR, reports related to the analyses of ribonucleic acids (RNAs) are few. Nevertheless, RNAs are versatile molecules involved in a multitude of roles in the cell. In this chapter, we present applications of FTIR for the structural analysis of RNA, including the analysis of helical parameters and noncanonical base pairing, often found in RNA. The effect of temperature pretreatment, which has a great impact on RNA folding, will also be discussed.

Effect of Temperature Pretreatment and Culture Media on Callus Induction and Regeneration in Composite Crosses between High Yielding Rice Cultivars and Ghaem line

Effect of Temperature Pretreatment and Culture Media on Callus Induction and Regeneration in Composite Crosses between High Yielding Rice Cultivars and Ghaem line

Facile synthesis of supported RuO2·xH2O nanoparticles on Co–Al hydrotalcite for the catalytic oxidation of alcohol: effect of temperature pretreatment

RuO2·xH2O/CoAl-LDH synthesized by the co-precipitation method was pretreated by different temperature which showed the highest activity at 200 °C.

Erratum to: The influence of phytohormones, wheat ovary co-culture, and temperature stress on anther culture response of watermelon (Citrullus lanatus L.)

The anther culture response of Citrullus lanatus L. was studied to evaluate the effect of growth regulators and wheat ovary-conditioned medium in Charleston Gray cultivar and the effect of temperature pretreatment in Crimson sweet cultivar. Callus-mediated embryogenesis was induced on Murashige and Skoog (MS) medium supplemented with 2, 4-dichlorophenoxyacetic acid (2,4-D) and a-naphthaleneacetic acid alone as well as 2,4-D in combination with N6-benzylaminopurine/kinetin (BAP/KN). Optimal percentage of embryogenic calli (EC) and mean number of embryos per anther (ME/A) were induced on MS medium supplemented with 2.0 µM 2, 4-D and 1.5 µM BAP in cultivar of Charleston Gray. In this cultivar, the inclusion of 10 wheat ovaries in the induction medium significantly increased the percentage of EC and ME/A up to 2.5- and 3-fold when compared with that in the control, respectively. Low-temperature pretreatment of flower buds (4 °C for 2 and 5 days) and cultured anthers (4 °C for 4 and 8 days) were tested in Crimson sweet cultivar and best response in terms of %EC and ME/A was obtained with pretreatment of cultured anthers at 4 °C for 4 days and flower buds at 4 °C for 2 days. Also, heat pretreatments of the cultured anthers at 30 °C for 7 and 32 °C for 2 days produced the highest percentage of EC compared to control and other heat pretreatments in Crimson sweet cultivar. The highest frequency of ME/A was obtained from cultured anthers incubated at 32 °C for 2 days. Embryos germinated into plantlets on MS medium containing 2.22 µM BAP, 3 % sucrose, and 0.8 % agar. The root tips of 12 regenerated plantlets were analyzed for ploidy level, of which 10 have been haploids.

Effects of temperature pretreatment on propane cracking over H-SSZ-13 zeolites

The effect of thermal treatment of SSZ-13 on catalytic activity has been investigated by using monomolecular propane conversion as a probe reaction.

Efficiency of SSR markers for determining the origin of melon plantlets derived through unfertilized ovary culture

The effects of temperature pre-treatment, thidiazuron, naphthaleneacetic acid, and 6-benzylaminopurine on in vitro gynogenic plant production from un-pollinated melon (Cucumis melo L.) ovaries were investigated. Simple sequence repeat (SSR) marker analysis was conducted to identify the homozygous diploid individuals. The temperature pre-treatment (4°C) for 4 days increased embryo formation frequency (63.3%) significantly. Addition of thidiazuron (0.04 and 0.02 mg/l) in the induction medium significantly increased the number of responding ovaries (46.6%, 65.83%), respectively. The maximum number of plantlet regeneration (22.5%) was achieved by culturing the ovary derived embryos on Murashigue and Skoog medium (MS medium) supplement with 0.6 mg/l 6-benzylaminopurine. Spontaneous doubled haploids originated directly through embryogenesis were subjected to genetic analysis using SSR molecular marker with 23 primers pair for homozygosity. SSR markers with microsatellite CMGA172, confirmed that the alleles in the parental material were also present in the gynogenic plantlets, but amplified only two alleles as compared to four alleles of the heterozygous parent material at same locus. Therefore these regenerated plantlets were consider homozygous and produced through a process of gametophytic embryogenesis.

Acid-redox properties of titania-supported 12-molybdophosphates for methanol oxidation

Physicochemical and catalytic properties of titania-supported 12-molybdophosphates have been investigated. The samples were characterized by the S(BET) method, Fourier-transform infrared (FTIR) and X-ray photoelectron (XPS) spectroscopies, temperature-programmed desorption (TPD) of ammonia and temperature-programmed reduction (TPR). The effect of temperature pretreatment on the catalytic behaviour of the samples in methanol oxidation was investigated. A significant change of selectivity to the main reaction products: dimethyl ether (DME) and formaldehyde (HCHO), as a function of the acid properties of the catalysts was observed. The highest selectivity to DME at 523 K suggested that the undecomposed molybdophosphoric acid (HPMo) on titania behaves as an acid catalyst. Pretreatment of the samples at higher temperatures (up to 723 K) and replacement of the protons in HPMo by cations (Co and Ni) lead to development of the redox properties (HCHO formation) of the catalyst, due to the suppression of the Brönsted acidity. The IR and XPS results provided clear evidence for the preservation of Keggin unit up to 623 K pretreatment after test reaction.

Effects of Temperature Pretreatment in the Dark on Photosynthesis of the Intact Spinach Chloroplast

Isolated, intact spinach (Spinacia oleracea L. var. "Long Standing Bloomsdale") chloroplasts were heated in the dark and the effect of this treatment on photosynthetic activities was determined at 25 degrees C. Dark incubation of the chloroplasts for 10 minutes at 35 degrees C and pH 8.1 resulted in a 50% decline in CO(2) photoassimilation. This decline in photosynthetic performance was dependent upon time, temperature, and medium pH with the optimum effect at acidic pH values. Photosynthetic decline was not observed if MgATP, MgADP, or a mixture of fructose 1,6-bisphosphate, aldolase, and oxaloacetate or ribose 5-phosphate and oxaloacetate was added prior to but not after the temperature pretreatment. A chloroplast preparation reconstituted with thylakoids and stroma from pretreated (35 degrees C, 10 minutes, pH 8.1) intact chloroplasts and supplemented with ferredoxin, ADP, and NADP was photosynthetically competent, indicating that ATP-coupled electron flow and the enzymes comprising the Benson-Calvin cycle remained stable during the dark treatment. In contrast, exposure of isolated thylakoids to 35 degrees C for 10 minutes uncoupled photophosphorylation from NADP and ferricyanide reduction. We propose that the decline of intact chloroplast photosynthesis is the result of a decrease in the content of or a change in the ratios of the adenine nucleotides. Maintenance of an adequate supply of adenine nucleotide is the effect of the externally added MgATP or of chloroplastic respiration of a sugar phosphate.

Effects of temperature pre-treatment, desiccation and aging on the viability of spores of halophilic blue-green algae

The effects of temperature, desiccation and aging on the viability of spores of Sambhar salt lake blue-green algae, Anabaena fertilissima and Anabaenopsis arnoldii, were studied. Spores of A. arnoldii were found to be more susceptible to temperature variation, desiccation and storage than spores of A. fertilissima. Pre-treatment of spores with higher temperatures, 37° and 47°C, stimulated germination in A. fertilissima. In a sporulated filament, spores which developed first were generally bigger and more resistant to adverse environmental conditions than spores formed later. The differential loss of viability in spores of a filament may be due to certain intrinsic differences in the physiological/ biochemical properties of the spores.

Effect of temperature pretreatment of achenes of Senecio serra on germination during stratification

Imbibed achenes of Senecio serra Hook., a forb common to high-elevation rangeland in Utah, were stratified at 1C for 20 weeks, with or without temperature pretreatments in the 30–10C range. The temperature pretreatments increased the rates of germination during stratification. The results are discussed in terms of advantageous effects of early germination under a snow cover that normally persists through May.

Effects of temperature pre-treatments on the forcing of strawberry plants (cv. Glasa)

The results of an experiment, designed to study the effects of certain temperature treatments during the autumn season on the subsequent development of strawberries (cv. Glasa) during forcing, have been presented in this paper. This study was under-taken in the interest of both breeding new varieties suitable for forcing and improving the present forcing methods.