The intersection of microfluidics and aptamer technologies holds particular promise for rapid progress in a plethora of applications across biomedical science and other areas. Here, the influence of microfluidics on the field of aptamers, from traditional capillary electrophoresis approaches through innovative modern‐day approaches using micromagnetic beads and emulsion droplets, is reviewed. Miniaturizing aptamer‐based bioassays through microfluidics has the potential to transform diagnostics and embedded biosensing in the coming years.

Microbial communities in rhizosphere interact with each other and form a basis of a cumulative impact on plant growth. Rhizospheric microorganisms like Piriformospora indica and Azotobacter chroococcum are well known for their beneficial interaction with plants. These features make P. indica /A. chroococcum co-inoculation of crops most promising with respect to sustainable agriculture and to understanding the transitions in the evolution of rhizospheric microbiome. Here, we investigated interactions of P. indica with A. chroococcum in culture. Out of five Azotobacter strains tested, WR5 exhibited growth-promoting while strain M4 exerted growth-inhibitory effect on the fungus in axenic culture. Electron microscopy of co-culture indicated an intimate association of the bacterium with the fungus. 2-D gel electrophoresis followed by mass spectrometry of P. indica cellular proteins grown with or without WR5 and M4 showed differential expression of many metabolic proteins like enolase-I, ureaseD, the GTP binding protein YPT1 and the transmembrane protein RTM1. Fungal growth as influenced by bacterial crude metabolites was also monitored. Taken together, the results conform to a model where WR5 and M4 influence the overall growth and physiology of P. indica which may have a bearing on its symbiotic relationship with plants.

The growing human population and depletion of resources have necessitated development of sustainable agriculture. Beneficial plant-microbe associations have been known for quite some time now. To maintain sustainability, one could show better reliance upon beneficial attributes of the rhizosphere microbiome. To harness the best agronomic traits, understanding the entire process of recruitment, establishment, and maintenance of microbiota as stable interactome within the rhizosphere is important. In this article, we highlight the process of recruitment and establishment of microbiota within rhizosphere. Further, we have discussed the interlinkages and the ability of multiple (microbial and plant) partners to interact with one another forming a stable plant holobiont system. Lastly, we address the possibility of exploring the knowledge gained from the holobiont system to tailor the rhizosphere microbiome for better productivity and maintenance of agroecosystems. The article provide new insights into the broad principles of stable plant-microbe interactions which could be useful for sustaining agriculture and food security.

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Epithelial-mesenchymal transition (EMT) is a programed course of developmental changes resulting in the acquisition of invasiveness and mobility in cells. In cancer, this course is used by epithelial cells to attain movability. Translationally controlled tumor protein (TCTP) has been extensively characterized following the observation on tumor reversion ensuing its depletion. However, the role of TCTP in cancer progression is still elusive. Here, we demonstrate for the first time that TCTP is a target of transforming growth factor-β1 (TGF-β1), a key regulator of EMT in A549 cells. We here present changes in expression patterns of intermediate filament markers (vimentin and cytokeratin 18a) of EMT following TCTP knockdown or over expression. The TCTP over-expression in cancer cells is associated with mesenchymal characters, while downregulation promotes the epithelial markers in the cells. Interaction of TCTP with β-catenin seems to stabilize β-catenin, preparative to its nuclear localization highlighting a role for β-catenin signaling in EMT. Moreover, the induction of urokinase plasminogen activator (uPA) following ectopic expression of TCTP leads to destabilization of ECM. The cells knocked down for TCTP show diminished invasiveness and migration under TGF-β1 treatment. The present results for the first time demonstrate that TGF-β1 dependent TCTP expression is required for EMT in cells.

DNAzymes have been limited in application by their low catalytic rates. Here, we evolved a new peroxidase DNAzyme mSBDZ-X-3 through a directed evolution method based on the capture of self-biotinylated DNA catalyzed by its intrinsic peroxidase activity. The mSBDX-X-3 DNAzyme has a parallel G-quadruplex structure and has more favorable catalytic properties than all previously reported peroxidase DNAzyme variants. We applied mSBDZ-X-3 in an aptamer-coupled proximity-based labeling proteomic assay to determine the proteins that bind to cell surface cancer biomarkers EpCAM and nucleolin. Confocal microscopy, western blot analysis, and LC−MS/MS showed that the hybrid DNAzyme aptamer-coupled proximity assay-labeled proteins associated with EpCAM and nucleolin within 6−12 min in fixed cancer cells. The labeled proteins were identified by mass spectrometry. This study provides a highly efficient peroxidase DNAzyme, a methodology for selection of such variants, and a method for its application in spatial proteomics using entirely nucleic acid-based tooling.

Piriformospora indica is a mycorrhiza like fungus of the order Sebacinales,which colonizes root and forms symbiosis with almost all terrestrial plants on earth. Information about the P. indica quantitative proteomics is limited.This limits our understanding of its multitrophic interaction with plants. A quantitative proteomic analysis of the fungus vis a vis its interaction with rhizospheric bacteria and the plant can reflect on the underlying proteins/enzymes. We describe a protocol for efficient extraction of cellular proteins from the fungus for two-dimensional gel electrophoresis following interaction with Azotobacter chroococcum in axenic culture. Polysaccharides and abundant salts present in Hill and Kaefer broth hinders extraction of protein from fungal biomass. Good quantity and quality of proteins are required for two-dimensional gel electrophoresis and proteomic analysis. We could use the extracts for proteomic analysis following a high resolution of 2-DE reference map of the fungus after interaction with A. chroococcum.

Treatment of cholera still is a global challenge for health authorities across the world. It is important to use effective antimicrobials for curbing cholera and shortens the duration of illness. As per the WHO recommendations, ciprofloxacin and doxycycline are drugs of choice to be used in treatment of severe cholera. Single doses of ciprofloxacin have been reported to be better than single dose of doxycycline in eradication of cholera bacterium from stool. Earlier we have reported that reduced susceptibility or resistance to fluoroquinolones in Vibrio cholerae O1 is associated with either delay or failure in cholera treatment. V. cholerae harbours two related type II topoisomerases, which alter DNA topology through a DNA cleavage complex. Fluoroquinolones stabilizing the DNA breakage‐reunion complex inhibit DNA replication. Point mutations in gyraseA and ParC responsible for reduced susceptibility to fluoroquinolones are well known. Here, we discuss the QnrVC mediated acquired mechanism of resistance in epidemic strains of V. cholerae. PCR analyses and DNA sequencing revealed presence of qnrVC gene (encoding QnrVC) in epidemic V. cholerae O1 in strains from central and Eastern parts of India. Higher order structural analyses confirmed that QnrVC exhibits right‐handed quadrilateral beta‐helical fold. The shape, size, and charge distribution on QnrVC is reminiscent of a 30‐bp long B‐form DNA. Docking studies revealed that it occupies the entire length of the G segment DNA binding site of type II topoisomerases, thus interfering with fluoroqunolone action. Strains harbouring the qnrVC elements were either resistant or less susceptible to ciprofloxacin as per CLSI, 2010 USA guidelines. Cloning of qnrVC in E. coli transformant mediated 4‐8 folds increment of MIC for ciprofloxacin. The use fluoroquinolones in cholera cases should be closely monitored and development of alternate chemotherapeutic agents targetting transition type II topoisomerases should be given due priority. Grant Funding Source: UGC, DBT and DST, Govt. of India