The Pi54 gene (Pi-k(h)) confers a high degree of resistance to diverse strains of the fungus Magnaporthe oryzae. In order to understand the genome-wide co-expression of genes in the transgenic rice plant Taipei 309 (TP) containing the Pi54 gene, microarray analysis was performed at 72 h post-inoculation of the M. oryzae strain PLP-1. A total of 1154 differentially expressing genes were identified in TP-Pi54 plants. Of these, 587 were up-regulated, whereas 567 genes were found to be down-regulated. 107 genes were found that were exclusively up-regulated and 58 genes that were down- regulated in the case of TP-Pi54. Various defence response genes, such as callose, laccase, PAL, and peroxidase, and genes related to transcription factors like NAC6, Dof zinc finger, MAD box, bZIP, and WRKY were found to be up-regulated in the transgenic line. The enzymatic activities of six plant defence response enzymes, such as peroxidase, polyphenol oxidase, phenylalanine ammonia lyase, β-glucosidase, β-1,3-glucanase, and chitinase, were found to be significantly high in TP-Pi54 at different stages of inoculation by M. oryzae. The total phenol content also increased significantly in resistant transgenic plants after pathogen inoculation. This study suggests the activation of defence response and transcription factor-related genes and a higher expression of key enzymes involved in the defence response pathway in the rice line TP-Pi54, thus leading to incompatible host-pathogen interaction.

Rice blast resistant gene, Pi54 cloned from rice line, Tetep, is effective against diverse isolates of Magnaporthe oryzae. In this study, we prospected the allelic variants of the dominant blast resistance gene from a set of 92 rice lines to determine the nucleotide diversity, pattern of its molecular evolution, phylogenetic relationships and evolutionary dynamics, and to develop allele specific markers. High quality sequences were generated for homologs of Pi54 gene. Using comparative sequence analysis, InDels of variable sizes in all the alleles were observed. Profiling of the selected sites of SNP (Single Nucleotide Polymorphism) and amino acids (N sites ≥ 10) exhibited constant frequency distribution of mutational and substitutional sites between the resistance and susceptible rice lines, respectively. A total of 50 new haplotypes based on the nucleotide polymorphism was also identified. A unique haplotype (H_3) was found to be linked to all the resistant alleles isolated from indica rice lines. Unique leucine zipper and tyrosine sulfation sites were identified in the predicted Pi54 proteins. Selection signals were observed in entire coding sequence of resistance alleles, as compared to LRR domains for susceptible alleles. This is a maiden report of extensive variability of Pi54 alleles in different landraces and cultivated varieties, possibly, attributing broad-spectrum resistance to Magnaporthe oryzae. The sequence variation in two consensus region: 163 and 144 bp were used for the development of allele specific DNA markers. Validated markers can be used for the selection and identification of better allele(s) and their introgression in commercial rice cultivars employing marker assisted selection.

The morphology and physicochemical properties of polydopamine are not totally inherent and undergo changes with differing reaction conditions like the choice of solvent used for polymerization. The polymerisation of dopamine to polydopamine carried out in different solvents like sodium hydroxide, sodium bicarbonate, PBS and Tris leads to polydopamine with exceptionally different morphological and physicochemical features with each solvent. Additionally, the different physicochemical characteristics and morphologies bestow the polymer films with different extents of antimicrobial activity. Moreover, the findings supported by chemical evidence from X-ray photoelectron spectroscopy reveal that higher antibacterial activities were obtained against E. coli and S. aureus with polydopamine films prepared by Tris and NaOH solvent induced polymerization. The antibacterial activity observed in saline was found to be higher than that in PBS medium for both E. coli and S. aureus. The higher antibacterial activity of polydopamine films prepared in Tris and NaOH solvents was attributed to the covalent incorporation of -OH groups on the surface provided by nucleophilic Tris and NaOH solvents during the polymerisation process. The distinct physicochemical and morphological changes were supported by the results from contact angle measurements, FE-SEM, EDAX, AFM, and XPS analysis. The present finding provides insight into the different chemistry, morphologies and properties of the designed polydopamine films with controlled antibacterial/antifouling properties. Additionally, new insights into the mechanism of formation, physicochemical changes in morphology and properties of polydopamine coatings were revealed.

HighlightsA novel taxol-producing A. fumigatus strain explored from the Northern Himalayan region.dbat and ITS genes were used as molecular markers for screening and identification.Hyper-production (1.6 g/L) of taxol in S7 medium, highest from an endophytic fungus.

Biodegradation of toxic amides by immobilized Rhodococcus rhodochrous NHB-2 has been studied to generate data for future development of reactors for the treatment of simulated wastewater containing various toxic amides. The whole resting cells were immobilized in different matrices like agar, polyacrylamide and alginate. Agar gel beads were selected for the treatment of simulated wastewater containing 100 mM each acetamide, propionamide, and 10 mM of acrylamide and packed in a highly compact five-stage plug flow reactor. The immobilized bacterium worked well in a broad pH range from 5 to 10, with an optimum at 8.7. The apparent Km-value for the turnover of acetamide for the resting cells was determined to be around 40 mM at pH 8.5 and 55 degreesC, whereas the Km-value of the purified amidase was predicted to be about 20 mM. This organism exhibited greater turnover of aliphatic amides as compared to aromatic amides. Although these cells showed maximal amide-degrading activity at 55 degreesC, simulated wastewater treatment was carried out at 45 degreesC, because of the greater stability of the amidase activity at that temperature. Of note, indices for overall temperature stability, based on the temperature dependence of apparent first order kinetic temperature denaturation constants, were determined to be) 7.9 +/- 1.1 x 10(-4), and -13.7 +/- 1.3 x 10(-4), -14.5 +/- 0.7 x 10(-4), and -13.7 +/- 0.8 x 10(-4) degreesC min, for free cells and cells immobilized in alginate, agar and polyacrylamide respectively. After 250 min the reactor showed maximum degradation of acetamide, propionamide and acrylamide of about 97, 100 and 90%, respectively by using 883 enzyme activity units per reactor stage. The results of this investigation showed that R. rhodochrous NHB-2 expressing thermostable amidase could be used for the efficient treatment of wastewater containing toxic amides. Therefore, we suggest that this microbe has a very high potential for the detoxification of toxic amides from industrial effluents and other wastewaters