Expression profiling and integrative analysis of the CESA/CSL superfamily in rice

<p>Abstract</p> <p>Background</p> <p>The cellulose synthase and cellulose synthase-like gene superfamily (<it>CESA</it>/<it>CSL</it>) is proposed to encode enzymes for cellulose and non-cellulosic matrix polysaccharide synthesis in plants. Although the rice (<it>Oryza sativa </it>L.) genome has been sequenced for a few years, the global expression profiling patterns and functions of the <it>OsCESA</it>/<it>CSL </it>superfamily remain largely unknown.</p> <p>Results</p> <p>A total of 45 identified members of <it>OsCESA</it>/<it>CSL </it>were classified into two clusters based on phylogeny and motif constitution. Duplication events contributed largely to the expansion of this superfamily, with Cluster I and II mainly attributed to tandem and segmental duplication, respectively. With microarray data of 33 tissue samples covering the entire life cycle of rice, fairly high <it>OsCESA </it>gene expression and rather variable <it>OsCSL </it>expression were observed. While some members from each <it>CSL </it>family (<it>A1</it>, <it>C9</it>, <it>D2</it>, <it>E1</it>, <it>F6 </it>and <it>H1</it>) were expressed in all tissues examined, many of <it>OsCSL </it>genes were expressed in specific tissues (stamen and radicles). The expression pattern of <it>OsCESA</it>/<it>CSL </it>and <it>OsBC1L </it>which extensively co-expressed with <it>OsCESA</it>/<it>CSL </it>can be divided into three major groups with ten subgroups, each showing a distinct co-expression in tissues representing typically distinct cell wall constitutions. In particular, <it>OsCESA1, -3 & -8 </it>and <it>OsCESA4, -7 & -9 </it>were strongly co-expressed in tissues typical of primary and secondary cell walls, suggesting that they form as a cellulose synthase complex; these results are similar to the findings in <it>Arabidopsis</it>. <it>OsCESA5</it>/<it>OsCESA6 </it>is likely partially redundant with <it>OsCESA3 </it>for OsCESA complex organization in the specific tissues (plumule and radicle). Moreover, the phylogenetic comparison in rice, <it>Arabidopsis </it>and other species can provide clues for the prediction of orthologous gene expression patterns.</p> <p>Conclusions</p> <p>The study characterized the <it>CESA</it>/<it>CSL </it>of rice using an integrated approach comprised of phylogeny, transcriptional profiling and co-expression analyses. These investigations revealed very useful clues on the major roles of <it>CESA</it>/<it>CSL</it>, their potentially functional complement and their associations for appropriate cell wall synthesis in higher plants.</p

Biosynthesis and characterization of silver nanoparticles from Cedrela toona leaf extracts: An exploration into their antibacterial, anticancer, and antioxidant potential

This research work aims to synthesize environmentally benign and cost-effective metal nanoparticles. In this current research scenario, the leaf extract of Cedrela toona was used as a reducing agent to biosynthesize silver nanoparticles (AgNPs). The synthesis of AgNPs was confirmed by the color shift of the reaction mixture, i.e., silver nitrate and plant extract, from yellow to dark brown colloidal suspension and was established by UV-visible analysis showing a surface plasmon resonance band at 434 nm. Different experimental factors were optimized for the formation and stability of AgNPs, and the optimum conditions were found to be 1 mM AgNO3 concentration, a 1:9 ratio of extract/precursor, and an incubation temperature of 70°C for 4 h. The Fourier transform infrared spectroscopy spectra indicated the presence of phytochemicals in the leaf extract that played the role of bioreducing agents in forming AgNPs. X-ray diffraction patterns confirmed the presence of AgNPs with a mean size of 25.9 nm. The size distribution and morphology of AgNPs were investigated by scanning electron microscopy, which clearly highlighted spherical nanoparticles with a size distribution of 22–30 nm with a mean average size of 25.5 nm. Moreover, prominent antibacterial activity was found against Enterococcus faecalis (21 ± 0.5 mm), Bacillus subtilis (20 ± 0.9 mm), Pseudomonas aeruginosa (18 ± 0.3 mm), Staphylococcus aureus (16 ± 0.7 mm), Klebsiella pneumoniae (16 ± 0.3 mm), and Escherichia coli (14 ± 0.7 mm). In addition, antioxidant activity was determined by DPPH and ABTS assays. Higher antioxidant activity was reported in AgNPs compared to the plant extract in both DPPH (IC50 = 69.62 µg·ml−1) and ABTS assays (IC50 = 47.90 µg·ml−1). Furthermore, cytotoxic activity was also investigated by the MTT assay against MCF-7 cells, and IC50 was found to be 32.55 ± 0.05 µg·ml−1. The crux of this research is that AgNPs synthesized from the Cedrela toona leaf extract could be employed as antibacterial, antioxidant, and anticancer agents for the treatment of bacterial, free radical-oriented, and cancerous diseases