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Fatty acid desaturases constitute a group of enzymes that introduce double bonds into the hydrocarbon chains of fatty acids to produce unsaturated fatty acids. In plants, seed-specific delta-12 fatty acid desaturase 2 (FAD2) is responsible for the high content of linoleic acid by inserting a double bond at the delta-12 (omega-6) position of oleic acid. In this study, sixteen FAD2 and FAD2-2 protein sequences from oilseeds were analyzed by computational tools including two databases of the NCBI and EXPASY and data management tools such as SignalP, TMHMM, Psort, ProtParam, TargetP, PLACE and PlantCARE. These services were used to predict the protein properties such as molecular mass, pI, signal peptide, transmembrane and conserved domains, secondary and spatial structures. The polypeptide sequences were aligned and a neighbour-joining tree was constructed using MEGA5.1 to elucidate phylogenetic relationships among FAD2 genes. Based on the phylogenetic analysis species with high similarity in FAD2 sequence grouped together. FAD2 proteins include highly conserved histidine-rich motifs (HECGHH, HRRHH and HV[A/C/T]HH) that are located by three to five transmembrane anchors. For further investigations Sesamum indicum FAD2 was selected and analyzed by bioinformatics tools. Analysis showed no N-terminal signal peptide for probable localization of FAD2 protein in cytoplasmic organelles such as chloroplast, mitochondria and Golgi. Instead the C-terminal signaling motif YNNKL, Y(K/N)NKF or YRNKI allows FAD2 protein to selectively bind to and embed in the endoplasmic reticulum. FAD2 promoter contains different cis-regulatory elements involve in the biotic and abiotic stresses response or control of gene expression specifically in seeds.

The low artemisinin content in Artemisia has caused this compound to be expensive among medicines. Several attempts have been made to increase its production by altering the expression of different genes. However, no approach has been cost-effective. In this study, the expression levels of SQS and DBR2 genes were quantified by qRT-PCR, and artemisinin content was measured by HPLC in Artemisia annua cell suspension culture under nano cobalt particles elicitation. For this purpose, nano cobalt particles were used in 0.25, 2.5, and 5 mg L -1 concentrations and samples were collected after 8, 24, 48, and 72 h. The highest artemisinin content was observed 24 h after 5 mg L -1 nano cobalt treatment. In this case, artemisinin production was 2.25-fold (113.35 mg g -1 dw) higher than that of the control. Simultaneously, the expression levels of SQS and DBR2 genes decreased. It appears that the decrease in the expression of SQS and DBR2 genes caused the artemisinin content to increase by high concentrations of the nano cobalt particles.

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This study sets out to compare the antibacterial and antibiofilm profiles of Ci/Ca EOs alone and in combination together against infectious bacterial strains. MIC assay was carried out to survey the effectiveness of prepared EOs by two-fold serial dilution method and MTT evaluation. Synergic antibacterial properties of EOs against target strains were studied by using checkerboard titration method. Biofilm growth and development were evaluated using CV and XTT reduction assays. Antibacterial activity was observed for EOs against both bacterial strains with stronger activity for CiEO against both bacteria. The synergistic antibacterial effect was observed only against B. subtilis. Based on the FIC index, combinations could not inhibit the growth of E. coli. The pure EOs and their combination inhibited cell attachment for both studied bacteria with stronger effect on E. coli. CV and XTT reduction assays results showed that Ci EO and its combination with CaEO had the highest antibiofilm activity at lowest MIC value 0.08% and 0.04/0.02% against biofilm formed by E. coli and B. subtilis respectively, indicating a high antibiofilm potential. Computational docking analyses also postulated that the active constituents of evaluated EOs have the potential to interact with different bacterial targets, suggested binding mode of action of EOs metabolites. By and large, synergistic anti-biofilm properties of EOs may provide further options for developing novel formula to inhibit a variety of infectious clinical and industrial strains without (or less) toxicity effects on human body. Graphical Abstract

A cost-effective and efficient approach for the synthesis of single-crystalline zinc oxide nanowires on vertically aligned multiwalled carbon nanotube (CNT) array is presented. ZnO nanowires are grown on the base of individual CNT through the low-temperature wet-chemical batch deposition technique, while the size and interspacing of the nanowires can be controlled by precursor concentration, growth temperature and time duration. The scanning electron microscopy image showed that the ZnO nanostructures are successfully grown on the CNT's surface uniformly. The produced nanostructures are characterized by x-ray diffraction, x-ray photoelectron spectroscopy and Raman spectroscopy. Also, field emission characteristics of the fabricated double-stage ZnO nanowire/CNT array are investigated and compared with the emission behaviour of CNT and ZnO nanowire arrays. The ZnO nanowire/CNT heterojunction array resulted in a low turn-on field of 1.5 V µm−1 and a threshold field of 4.5 V µm−1, which were lower than both the vertical CNT and ZnO arrays. The field emission properties and stability of the fabricated nanostructures also demonstrated great potential for field emission applications.

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