23 research outputs found

    Nutrient Uptake and Utilization and Antioxidants of Fruits in Red Raspberry (Rubus idaeus L.) Cultivar ‘Autumn Bliss’ in response to Fertilization under Extended Photoperiod

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    Annual-fruiting cultivars of red raspberry (Rubus idaeus L.) complete its entire cycle of vegetative growth, flowering, and fruiting in one growing season, which has not been well studied in response to treatments of photoperiod and fertilization. In this study, micro-propagated plantlets of ‘Autumn Bliss’ were planted in a greenhouse at Dalian, Northeast China. Some were treated with fertilizers at the rate of 12 g per plant (N-P2O5-K2O, 14-14-14) under extended photoperiod of 17 h with PPFD of 240 μmol m-2 s-1 at dark-time (Pho.+Fert.), while others were treated with longer photoperiod (Pho.) or with the control. Compared to the control, both growth and biomass in shoot part of ‘Autumn Bliss’ were promoted by the Pho.+Fert. treatment, but foliar nutrients declined as the symptom of nutrient dilution. The Pho. treatment had no effect on either growth or nutrient uptake in leaves, resulting in the symptom of nutrient depletion compared to the Control. Soil P availability positively correlated with foliar P concentration but negatively correlated with root length. Only the Pho.+Fert. treatment resulted in the advance of fruiting by two months at July when fruits were measured to have acceptable fruit weight of about 3 g and contents of anthocyanin at ~26.4 mg cyaniding-3-glucoside equiv. 100 g-1 Fw and total phenolic content at ~17.5 mg GAE 100 g-1 Fw

    Molecular Dynamics Analysis Reveals Structural Insights into Mechanism of Nicotine N-Demethylation Catalyzed by Tobacco Cytochrome P450 Mono-Oxygenase

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    CYP82E4, a cytochrome P450 monooxygenase, has nicotine N-demethylase (NND) activity, which mediates the bioconversion of nicotine into nornicotine in senescing tobacco leaves. Nornicotine is a precursor of the carcinogen, tobacco-specific nitrosamine. CYP82E3 is an ortholog of CYP82E4 with 95% sequence identity, but it lacks NND activity. A recent site-directed mutagenesis study revealed that a single amino acid substitution, i.e., cysteine to tryptophan at the 330 position in the middle of protein, restores the NND activity of CYP82E3 entirely. However, the same amino acid change caused the loss of the NND activity of CYP82E4. To determine the mechanism of the functional turnover of the two molecules, four 3D structures, i.e., the two molecules and their corresponding cys–trp mutants were modeled. The resulting structures exhibited that the mutation site is far from the active site, which suggests that no direct interaction occurs between the two sites. Simulation studies in different biological scenarios revealed that the mutation introduces a conformation drift with the largest change at the F-G loop. The dynamics trajectories analysis using principal component analysis and covariance analysis suggests that the single amino acid change causes the opening and closing of the transfer channels of the substrates, products, and water by altering the motion of the F-G and B-C loops. The motion of helix I is also correlated with the motion of both the F-G loop and the B-C loop and; the single amino acid mutation resulted in the curvature of helix I. These results suggest that the single amino acid mutation outside the active site region may have indirectly mediated the flexibility of the F-G and B-C loops through helix I, causing a functional turnover of the P450 monooxygenase

    Application of Gene Chip and Data Processing

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    The Internet will be How to Change the Landscape Industry

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