Identification of stress-responsive genes in an indica rice (Oryza sativa L.) using ESTs generated from drought-stressed seedlings

The impacts of drought on plant growth and development limit cereal crop production worldwide. Rice (Oryza sativa) productivity and production is severely affected due to recurrent droughts in almost all agroecological zones. With the advent of molecular and genomic technologies, emphasis is now placed on understanding the mechanisms of genetic control of the drought-stress response. In order to identify genes associated with water-stress response in rice, ESTs generated from a normalized cDNA library, constructed from drought-stressed leaf tissue of an indica cultivar, Nagina 22 were used. Analysis of 7794 cDNA sequences led to the identification of 5815 rice ESTs. Of these, 334 exhibited no significant sequence homology with any rice ESTs or full-length cDNAs in public databases, indicating that these transcripts are enriched during drought stress. Analysis of these 5815 ESTs led to the identification of 1677 unique sequences. To characterize this drought transcriptome further and to identify candidate genes associated with the drought-stress response, the rice data were compared with those for abiotic stress-induced sequences obtained from expression profiling studies in Arabidopsis, barley, maize, and rice. This comparative analysis identified 589 putative stress-responsive genes (SRGs) that are shared by these diverse plant species. Further, the identified leaf SRGs were compared to expression profiles for a drought-stressed rice panicle library to identify common sequences. Significantly, 125 genes were found to be expressed under drought stress in both tissues. The functional classification of these 125 genes showed that a majority of them are associated with cellular metabolism, signal transduction, and transcriptional regulation

Functional genomics of drought stress response in rice: transcript mapping of annotated unigenes of an indica rice (Oryza sativa L. cv. Nagina 22)

Rice being one of the widely cultivated cereals across diverse agroecological systems, is prone to high yield losses due to recurring droughts. In India, drought is a major constraint of rice production and accounts for as much as 15% of yield losses during some years. Conventional plant breeding techniques though cumbersome and time-consuming, have been immensely helpful in releasing drought-tolerant varieties. However, this is not adequate to cope up with the future demand for rice, as drought seems to spread to more regions and seasons across the country. Understanding the genes that govern rice plant architecture and response to drought stress is urgently needed to enhance breeding rice with improved drought tolerance. In order to identify genes associated with drought stress response and their temporal and spatial regulation, we took the genomic approach. By generating a large set of expressed sequence tags (ESTs) from cDNA libraries of drought-stressed seedlings and transcript profiling, we identified 589 genes presumed to be involved in drought stress. These 5814 ESTs are assembled into 2094 contigs and localized onto chromosome arms. We present here the physical map of the 2094 unigene set along with 589 annotated putative stress responsive genes of rice. Further, using ESTs, a few of drought quantitative trait loci (QTLs) have been dissected and putative candidate genes identified. This will be useful to rice researchers as ready reference source for breeding through developing candidate gene markers, molecular dissection of QTLs associated with drought stress and map-based cloning

Oral administration of bovine milk-derived extracellular vesicles induces senescence in the primary tumor but accelerates cancer metastasis

The concept that extracellular vesicles (EVs) from the diet can be absorbed by the intestinal tract of the consuming organism, be bioavailable in various organs, and in-turn exert phenotypic changes is highly debatable. Here, we isolate EVs from both raw and commercial bovine milk and characterize them by electron microscopy, nanoparticle tracking analysis, western blotting, quantitative proteomics and small RNA sequencing analysis. Orally administered bovine milk-derived EVs survive the harsh degrading conditions of the gut, in mice, and is subsequently detected in multiple organs. Milk-derived EVs orally administered to mice implanted with colorectal and breast cancer cells reduce the primary tumor burden. Intriguingly, despite the reduction in primary tumor growth, milk-derived EVs accelerate metastasis in breast and pancreatic cancer mouse models. Proteomic and biochemical analysis reveal the induction of senescence and epithelial-to-mesenchymal transition in cancer cells upon treatment with milk-derived EVs. Timing of EV administration is critical as oral administration after resection of the primary tumor reverses the pro-metastatic effects of milk-derived EVs in breast cancer models. Taken together, our study provides context-based and opposing roles of milk-derived EVs as metastasis inducers and suppressors

Effect of nitrogen pressure on mechanical properties of nc-TiAlN/a-Si 3 N 4 nanocomposite coatings deposited by cathodic arc PVD process

The present work investigates effect of nitrogen pressure on composition and mechanical properties of superhard nc-TiAlN/a-Si3N4 nanocomposite coatings deposited by cathodic arc PVD process. As the nitrogen pressure increases, at.% ratio of (Al+Si)/Ti, initially, increases to a maximum and thereafter, it decreases while the nitrogen content follows the reverse trend. Hardness is influenced by chemical composition and crystallite size of TiAlN phase. Maximum average hardness of 37 GPa is achieved when at.% ratio of Al(+Si)/Ti or N/(Ti+Al+Si) approaches 1.0 and decrease in scratch adhesion strength is attributed to the defects caused by nitrogen deficiency.</p

Viscosity studies of some 1:1 electrolyte solutions in N-methyl- 2-pyrrolidinone at 25°C

898-900The relative viscosities of solutions ofLiO4, LiClO4, NaNO3. NaSCN. Kl, KSCN, AgNO3, Bu4NBr, Bu4NI, NaBPh4 and Bu4NBPh4 have been measured in the concentration range (6.89744.0)x 10-4mol dm-3 in N-methyl-2-pyrrolidinone at 25&deg;C. The viscosity data have been analysed by the Jones-Dole equation and viscosity B-coefficients have been found to be positive. Ionic viscosity B- coefficients are obtained by splitting B-coefficients of Bu4NBPh4 &nbsp;into contributions due to individual ions in terms of their radii. The ionic viscosity B-coefficients follow the order: Li+&gt; Na+ &gt; K+ and BPh4- &gt; SCN- &gt; Br-&gt; I-&gt; CIO4- &gt; NO3- &gt; Cl-

Seasonal effect on compressive strength of ambient cured, nominal mix proportioned alkali-activated slag concrete

Abstract Strength of the concrete is a very important factor for the safe design of concrete and safe construction. Nowadays high strength concrete has an important role in the construction of different structures. It is difficult to enhance the strength of the concrete and enhancing strength requires a lot of changes in the mix design. The present study is to develop Geopolymer concrete to increase the compressive strength of low nominal mix proportions using alkali actuators like NaOH and Na2SiO3 solutions. Geopolymer concrete is one of the best alternative concrete for conventional and other cement concretes for many reasons. The Geopolymer concrete is prepared with ground granulated blast furnace slag (GGBS) and silica fume (SF) as a binder. NaOH and Na2SiO3 solutions are adopted as alkali activators. Quartz sand is used as fine aggregate along with normally used coarse aggregate. Cubes are prepared with different combinations of ingredients and after 28 days of ambient curing conditions, the cubes are tested for compressive strength. And this study is conducted in summer, monsoon and winter seasons to study the effect of seasons on ambient curing of the Geopolymer concrete.</jats:p

Fracture behaviour of nc-TiAlN/a-Si 3

Cyclic nanoimpact tests were carried on nc-TiAlN/a-Si3N4 nanocomposite, TiN and multilayered TiN/nanocomposite (NC) coatings to evaluate their resistance to fracture under cyclic impact loads. Fracture behaviour of the coatings was ascertained from fracture probability obtained from time-depth curves and focus ion beam milling images of resulting indentation impressions. TiN coating mainly showed intercolumnar cracks while the other coatings showed other modes of cracking, that is, lateral, inclined, bending, edge cracks, during testing. The performance ranking of the coatings, TiN &amp;gt; TiN/NC &amp;gt; nc-TiAlN/a-Si3N4, is linked to their β0 value, representing relative indentation depth of the coating-substrate composite hardness system at which the fractional hardness improvement equal to 50% of the maximum is retained and also their corresponding microstructure. Apart from enabling prediction of fracture resistance of the coatings, these studies provide useful insights into design and selection of coating materials for targeted machining applications. © 2016 Institute of Materials, Minerals and Mining</p