Development of PCR-based markers from the tomato glutamate oxaloacetate transaminase isozyme gene family as a means of revitalising old isozyme markers and recruiting new ones

Sequences annotated as aspartate aminotransferases (synonymous with glutamate oxaloacetate transaminases) in the SOL Genomics Network unigene database were used to design 10 pairs of PCR primers for genetic marker development. These primer pairs generated nine CAPS markers, two SCAR markers and one SSR marker, which were bin-mapped using a set of tomato introgression lines (IL) derived from Lycopersicon esculentum cv. M82 and Lycopersicon pennellii LA716. Based on their bin locations, these markers are largely dispersed throughout the tomato genome and appear to have tagged all four of the glutamate oxaloacetate transaminase (Got) isozyme marker genes placed on the classical genetic map of tomato. Orthologous relationships with Arabidopsis aspartate aminotransferase (Asp) genes suggest the existence of at least two additional functional Got genes in tomato that have also been tagged by these markers and likewise an additional functional Asp gene in Arabidopsis. The Got-2 isozyme marker has often been used for the marker-assisted breeding of the I-3 gene for Fusarium wilt resistance introgressed from L. pennellii LA716. The Got-2 CAPS marker that we have developed offers a facile PCR-based alternative to the isozyme marker for the marker-assisted breeding of I-3. However, all of the PCR-based markers we have developed have the potential to assist the breeding of linked traits introgressed from wild relatives of tomato.     

Glutamate oxaloacetate transaminase activity in developing Lycopersicon esculentum fruit

Glutamate oxaloacetate transaminase (GOT) occurs in both the mitochondrial and cytoplasmic fractions from tomato fruit tissue. Changes in activity of the enzyme from fruit at selected developmental stages have been followed. The combined activity fell from the immature green stage to the full red condition whilst the proportion in the mitochondria reached a peak in green-orange fruit. The activity of cytoplasmic, but not mitochondrial, GOT was stimulated by the addition of pyridoxal-5-phosphate. In the green areas of fruit showing blotchy ripening, the combined activity was equivalent to that in normal immature green fruit but with a much higher proportion of the activity in the mitochondria. Mitochondrial GOT could constitute a system in ripening tomato fruit whereby the accumulation of inhibitory concentrations of oxaloacetate affecting the oxidation of succinate and malate might be controlled.     

Synthesis of 1-Deoxy-L-rhamnojirimycin and Its Inhibitory Action against α-L-Rhamnosidase

To enhance the storage stability of essential oils such as d-limonene, a mixed powder of β-cyclodextrin and maltodextrin was used to encapsulate the liquid flavor in a powder state. In this study, powdery encapsulation of d-limonene was done by direct kneading of d-limonene with the mixed powder at low water content, using a twin screw kneader. The retention of d-limonene in the periodically sampled powder reached a maximum when the mass ratio of β-cyclodextrin to maltodextrin in the mixed powder equaled unity and the initial molar ratio of d-limonene to β-cyclodextrin was larger than unity. From X-ray diffraction of the powder, it could be guessed that the maximum retention of d-limonene might come from the adsorption of d-limonene upon maltodextrin. The equilibrium retention of d-limonene in the dry powder depended not only upon the mass ratio of β-cyclodextrin to maltodextrin in the mixed powder, but upon the initial moisture content in the powder. The equilibrium retention could be estimated well by a simple calculation.     

Pyruvate kinase in pig liver mitochondria

The existence of the pyruvate kinase (PK) in pig liver mitochondria was shown by monitoring photometrically the PK reaction in solubilised mitochondria with either phosphoenolpyruvate (PEP) or ADP used as a substrate. In distinction with the cytosolic isoenzyme, the mitochondrial PK showed a sigmoidal dependence on either PEP or ADP concentrations. The occurrence of the mitochondrial PK was confirmed by immunological analysis. Titration with digitonin showed that mPK is restricted to the matrix. PEP addition to mitochondria resulted in reduction of the intramitochondrial NAD(P)⁺ inhibited by either the non-penetrant thiol reagent mersalyl or by arsenite, an inhibitor of the pyruvate dehydrogenase complex. Citrate/oxaloacetate appearance outside mitochondria also occurred as result of PEP addition to PLM. Taken together these findings support a role for PEP itself in triggering fatty acid synthesis via its mitochondrial metabolism.     

Enhancement of pyruvate production byTorulopsis glabrata through supplement of oxaloacetate as carbon source

The capability of utilizing a TCA cycle intermediates as the sole carbon source by the multi-vitamin auxotrophic yeastTorulopsis glabrata CCTCC M202019 was demonstrated with plate count method. It is indicated thatT. glabrata could grew on a medium with one of the TCA cycle intermediates as the sole carbon source, but more colonies were observed when glucose, acetate and one of the TCA cycle intermediates coexisted in the medium. Among the intermediates of the TCA cycle examined in this study, cell growth was improved by supplementing oxaloacetate. Further investigation showed that the presence of acetate was necessary when oxaloacetate was supplemented. By supplementing with 10 g/L of oxaloacetate in pyruvate batch fermentation, dry cell weight increased from 11.8 g/L to 13.6 g/L, and pyruvate productivity was enhanced from 0.96 gL⁻¹h⁻¹ to 1.19 gL⁻¹h⁻¹ after cultivation of 56 h. The yield of pyruvate to glucose was also improved from 0.63 g/g to 0.66 g/g. These results indicate that under vitamins limitation, the productivity and yield of pyruvate could be enhancedvia an increase of cell growth by the supplementation of oxaloacetate.     

Subacute toxic effects of silver nanoparticles oral administration and withdrawal on the structure and function of adult Albino Rats’ hepatic tissue

Products containing Silver nanoparticles (Ag NPs) are becoming vastly used in our daily life. The widespread increased introduction of Ag NPs in many aspects of life has raised researchers' concerns regarding their safety and toxicity for biological and environmental life in the past few years. The current study aimed to explore the subsequent effects of Ag NPs withdrawal, following short-term oral administration. Eighteen rats were assigned randomly into three groups (control group "1" and AG NPs treated groups "2" and "3"; 6 animals each). The control group received normal food and tap water while groups 2 & 3 received 0.5 ml of a solution containing 25 ppm Ag NPs for 14 days. Group 2 rats were sacrificed on day 14 whereas group 3 was left for another 14 days of particle cessation followed by euthanasia on day 28. Functional assessment was done by liver enzyme assays, hydrogen peroxide activity, hepatic Bdnf expression, and P53 immunoreactivity. Hepatic tissue structural assessment was done via hematoxylin and eosin, periodic acid-Schiff as well as Masson's trichrome stains. The results revealed a significant elevation of Hydrogen peroxide in group 2 only compared to the control group. Hepatic Bdnf and liver enzymes were both insignificantly affected. Structural abnormalities and enhanced apoptosis in hepatic tissue were found 14 days after ceasing the nanoparticles. In conclusion: Structural and functional insults following Ag NPs oral administration continues after particle withdrawal, and interestingly they do not necessitate apparent reflection on liver enzyme assays.     

组织培养创造抗白粉病小麦-簇毛麦染色体易位及分子标记辅助选择

对175株普通小麦与6D/6V代换系杂种当代幼胚培养再生植株进行谷草转氨酶同工酶分析,其中来自杂交组合遗4095×RW15（6D／6V代换系）的2个植株（编号分别为98R149和98R159）GOT—V     

Thiazolidine-2-carboxylate derivatives formed from glyoxylate and L-cysteine or L-cysteinylglycine as possible physiological substrates for D-aspartate oxidase

Adducts of glyoxylate with L-cysteine or L-cysteinylglycine were found to be excellent substrates at low concentrations for beef kidney D-aspartate oxidase. Evidence is presented that cis-thiazolidine-2,4-dicarboxylate and its glycine amide are the actual substrates, and that both are converted in the enzymic reaction to 4-substituted thiazoline-2-carboxylates. The results imply that these thiazolidine derivatives are the likely physiological reactants for mammalian D-aspartate oxidase.