Reduction of Bacterial Adhesion on Ag-TiO₂ Coatings

Ag-TiO2 nano-composite coatings showed the synergistic effect on the anti-bacterial activity. However, little was known on the mechanism of the enhanced anti-bacterial effect. In this paper, a range of Ag-TiO2 nano-composited coating with different TiO2 contents were prepared on titanium substrate using an electroless deposition technique and the antibacterial performance of the coatings were evaluated with E.coli and S.aureus. This work demonstrated for the first time that the incorporation of TiO2 nano-particles into Ag matrix not only significantly promoted the Ag ion release, but also significantly increased the electron donor surface energy, which lead to the enhanced antibacterial effect of the Ag-TiO2 coatings

Simplified extraction of good quality genomic DNA from a variety of plant materials

Depending on the nature and complexity of plant material, proper method needs to be employed for extraction of genomic DNA, along with its performance evaluation by different molecular techniques. Here, we optimized and employed a simple genomic DNA isolation protocol suitable for a variety of plant materials covering in vitro grown tender plantlets to relatively complex plant tissues such as field grown mature potato leaves and tubers. Unlike other methods, no detergent was included in the isolation steps. This protocol, based on Dellaporta’s method as reported earlier, worked efficiently both at small and miniscale during handling large number of plant materials. DNA yield was found to be in the range of 70 to 120 μg per gram of the plant material; sufficient for most of the molecular techniques. Purity of DNA was checked by A260/A280 ratio, and restriction analyses including the isoschizomers HpaII and MspI. The DNA preparations were successfully used in polymerase chain reactions using genespecific primers for cloning of different genes. Prolonged storage did not affect the quality of the DNA samples. Taken together, this method could be a reliable substitute to frequently used chemical cetyl trimethylammonium bromide (CTAB) and commercial kits-based plant DNA isolation protocols.Key words: Plant materials, genomic DNA isolation, restriction analyses, HpaII and MspI isoschizomers, genespecific primers, polymerase chain reaction (PCR), molecular cloning, DNA storag

In silico model of DSF synthase RpfF protein from Xanthomonas oryzae pv. Oryzae: A novel target for bacterial blight of rice disease

Background: Rice plant diseases play a major role as biological constraints on production. One of such rice disease is bacterial leaf blight, caused by Xanthomonas oryzae pv. Oryzae (Xoo). The diffusible signal factor (DSF) synthesized by Xoo has a major role in virulence to rice plant. The DSF synthase RpfF protein, which is related to crotonase superfamily is responsible for the maintaining concentration of DSF. DSF-dependent quorum sensing (QS) system adopts protein- protein interaction mechanism to auto regulates the production of DSF. The antibacterial activity of pesticides against Xoo has not yet been completely understood. Three dimensional structure of RpfF protein was predicted using homology modeling method by MODELLER 9V9 software, SWISS MODEL and GENO3D online tools and structures were validated by Ramachandran plot, TM-Score and RMSD. 3D structure of RpfF (accession number AAL06345) was predicted using DSF synthase of Xanthomonas campestris pv. campestris (Xcc) (PDB ID: 3M6M) as a template. The stereo chemical check reveals the structure developed from the modeller was the best one and the potential ligand binding sites were identified by CASTp Server. The predicted RpfF model provides insight into its structure, active sites and aid in the development of novel inhibitors to control bacterial leaf blight in rice plant. DSF synthase RpfF protein could be used as a novel target to control infectio