Study of genotypic variation of cultivars of winged bean [Psophocarpus tetragonolobus (Stickm.) DC.] with the help of n-alkane profile

The leaf cuticle is covered by epicuticular wax consisting mainly of straight-chain aliphatic hydrocarbons with a variety of substituted groups. Studies have been concentrated on n-alkanes in epicuticular wax of Winged bean [Psophocarpus tetragonolobus (Stickm.) DC.]. Hydrocarbon constituents especially n-alkane analyses of seven cultivars of Winged bean [Psophocarpus tetragonolobus (Stickm.) DC.] have been undertaken. All the n-alkanes in between C₁₄–C₁₈ and C₂₀–C₃₈ are present in each of the species. Among the species, amount of n-alkanes is maximum in IC112417 and relatively low in EC38825. Scanning electron microscopic views were also taken for epicuticular layers and their hydrocarbons of the leaves of all the genotype species of the plant. Qualitative and quantitative characterization of n-alkanes present in the epicuticular wax extracted from the mature leaves can be used as an effective tool in chemo taxonomical work and also for the study of genotypic variation of the different cultivars.     

A bioluminescent assay for monitoring conjugation of ubiquitin and ubiquitin-like proteins

Post-translational modification of target proteins by ubiquitin (Ub) and ubiquitin-like (Ubl) proteins is a critical mechanism for regulating protein functions affecting diverse cellular processes. Ub/Ubl proteins are conjugated to lysine residues in substrate proteins through an adenosine triphosphate (ATP)-dependent enzymatic cascade involving enzyme 1 (E1)-activating enzyme, E2-conjugating enzyme, and E3 ligase. The amount of adenosine monophosphate (AMP) produced in the first step, involving E1-mediated Ub/Ubl activation, represents an accurate measure of Ub/Ubl transfer during the process. Here we describe a novel bioluminescent assay platform, AMP-Glo, to quantify Ub/Ubl conjugation by measuring the AMP generated. The AMP-Glo assay is performed in a two-step reaction. The first step terminates the ubiquitination reaction, depletes the remaining ATP, and converts the AMP generated in the ubiquitination reaction to adenosine diphosphate (ADP), and in the second step the ADP generated is converted to ATP, which is detected as a bioluminescent signal using luciferase/luciferin, proportional to the AMP concentration and correlated with the Ub/Ubl transfer activity. We demonstrate the use of the assay to study Ub/Ubl conjugation and screen for chemical modulators of enzymes involved in the process. Because there is a sequential enhancement in light output in the presence of E1, E2, and E3, the AMP-Glo system can be used to deconvolute inhibitor specificity.     

Crosstalk of moderate ROS and PARP-1 contributes to sustainable proliferation of conditionally reprogrammed keratinocytes

Conditionally reprogrammed cell (CRC) technique is a promising model for biomedical and toxicological research. In the present study, our data first demonstrated an increased level of PARP-1 in conditionally reprogrammed human foreskin keratinocytes (CR-HFKs). We then found that PARP inhibitor ABT-888 (ABT), reactive oxygen species (ROS) scavenger N-acetyl-l -cysteine (NAC), or combination (ABT + NAC) were able to inhibit cell proliferation, ROS, PARP-1, and ROS related protein, NRF2, and NOX1. Interestingly, knockdown of endogenous PARP-1 significantly inhibited cell proliferation, indicating that the increased PARP-1 expression was critical for CR. Importantly, we found that a moderate level of ROS contributed the cell proliferation and increased PARP-1 since knockdown of PARP-1 also inhibited the ROS. The similar inhibition of cell proliferation, ROS, and expression of PARP-1 and NRF2 proteins was observed when CR-HFKs were treated with hydroquinone (HQ), a key component from skin-lightening products. Moreover, the treatment of HQ plus treatment of ABT, NAC, or combination can further inhibit cell proliferation, ROS, expression of PARP-1, and NRF2 proteins. PARP-1 knockdown inhibited the population doubling (PDL) and treatment of HQ inhibited the PDL further, as well as the change of ROS. Finally, we discovered that pathways including cyclin D1, NRF2, Rb and pRb, CHK2, and p53, were involved in cell proliferation inhibition with HQ. Taken together, our findings demonstrated that crosstalk between ROS and PARP-1 involves in the cell proliferation in CR-HFKs, and that inhibition of CR-HFK proliferation with HQ is through modulating G1 cell cycle arrest.     

Enhancement of Catalytic Efficiencies of Xylanase,Pectinase and Cellulase by Microwave Pretreatment of their Substrates

Microwave pre-treatment of polygalacturonic acid, xylan and carboxymethylcellulose was found to improve the catalytic efficiencies of pectinase, xylanase and cellulase by 1.5, 2.3 and 1.6 fold, respectively. The microwave effect was distinguished from a pure thermal effect by irradiating at a constant temperature with the help of a non-contact infrared controller. The temperature and time of pre-treatment and substrate concentration during the pre-treatment were optimized by response surface methodology. Scanning electron microscopy revealed significant morphological changes in the substrate as a result of microwave pre-treatment. The time course of enzymatic hydrolysis in each case showed that the use of microwave pre-treated substrates gave higher catalytic rates. Also, a higher degree of bioconversion was observed in each case when microwave pre-treated substrates were used.     

Allantoin mediated regulation of miRNAs for short term salinity stress tolerance in Oryza sativa L. cv. IR-29

Journal of Plant Biochemistry and Biotechnology - Salinity affects plant in a variety of ways, including ion toxicity, osmotic stress and oxidative damage. Allantoin is a nitrogenous compound...