Triterpenes and Pheophorbides from Camellia ptilosperma and Their Cytotoxicity, Photocytotoxicity, and Photodynamic Antibacterial Activity.

Phytochemical investigation of the leaves of Camellia ptilosperma S. Y. Liang et Q. D. Chen led to the isolation of ten undescribed compounds, including six new triterpenes (1-6) and four new pheophorbide-related compounds (7-10). Meanwhile, the cytotoxic activity of the six triterpenes against six cancer cell lines was evaluated by MTT assay. Compound 2 showed potent cytotoxicity toward HepG2 cells with an IC50 value of 2.57 µM. Compounds 4 and 5 exhibited cytotoxicity against MDA-MB231 cells, with IC50 values of 11.31 and 5.52 µM, respectively. Additionally, the cytotoxicity of four new pheophorbides against these cancer cells was evaluated both in the presence and absence of light treatment. Compound 7 exhibited exceptional photocytotoxicity against Hela, MCF-7, and A549 cells, with IC50 values of 0.43 µM, 0.28 µM, and 0.92 µM, respectively. Compound 10 demonstrated significant photodynamic cytotoxic activity against BEL-7402 and HepG2 cells with IC50 values of 0.77 µM and 0.33 µM, respectively. The photodynamic antibacterial activity of 7-10 was also tested for S. aureus, E. coli, K. pneumoniae, and P. aeruginosa under direct illumination. Compounds 8 and 10 exhibited sensitivity to E. coli and demonstrated a photodynamic antibacterial effect, with a MIC value of 0.625 µM.

Global transcriptome changes of elongating internode of sugarcane in response to mepiquat chloride.

BACKGROUND: Mepiquat chloride (DPC) is a chemical that is extensively used to control internode growth and create compact canopies in cultured plants. Previous studies have suggested that DPC could also inhibit gibberellin biosynthesis in sugarcane. Unfortunately, the molecular mechanism underlying the suppressive effects of DPC on plant growth is still largely unknown. RESULTS: In the present study, we first obtained high-quality long transcripts from the internodes of sugarcane using the PacBio Sequel System. A total of 72,671 isoforms, with N50 at 3073, were generated. These long isoforms were used as a reference for the subsequent RNA-seq. Afterwards, short reads generated from the Illumina HiSeq 4000 platform were used to compare the differentially expressed genes in both the DPC and the control groups. Transcriptome profiling showed that most significant gene changes occurred after six days post DPC treatment. These genes were related to plant hormone signal transduction and biosynthesis of several metabolites, indicating that DPC affected multiple pathways, in addition to suppressing gibberellin biosynthesis. The network of DPC on the key stage was illustrated by weighted gene co-expression network analysis (WGCNA). Among the 36 constructed modules, the top positive correlated module, at the stage of six days post spraying DPC, was sienna3. Notably, Stf0 sulfotransferase, cyclin-like F-box, and HOX12 were the hub genes in sienna3 that had high correlation with other genes in this module. Furthermore, the qPCR validated the high accuracy of the RNA-seq results. CONCLUSION: Taken together, we have demonstrated the key role of these genes in DPC-induced growth inhibition in sugarcane.

Hemicellulose-rich transparent wood: Microstructure and macroscopic properties.

Hemicellulose plays a vital role in nature wood matrix. Here, we first demonstrate the significance of hemicellulose for improving the microstructure and macroscopic properties of transparent wood (i.e. wood/polymer composite), an emerging structural material. A delignified basswood templet with high hemicellulose content (~23 wt%) and well-preserved cellulose supramolecular structure was prepared via a peracetic acid-based process. This hemicellulose-rich delignified wood templet possesses nearly intact cell wall structure and sufficient space in the lumen and middle lamella for petroleum-based polymer space-filling. Consequently, the resultant hemicellulose-rich wood/PMMA composite exhibits high optical transmittance (~85 %), medium haze (~72 %), acceptable optical stability as well as excellent mechanical strength (tensile strength of 165.3 MPa and toughness of 1.65 MJ/m3), benefitting from the absence of microstructural defects and heterogeneity in the matrix. It is anticipated that our study would provide new insights into the fabrication of advanced transparent wood material from the point-of-view of wood chemical composition.

Enhanced Activity of Genes Associated With Photosynthesis, Phytohormone Metabolism and Cell Wall Synthesis Is Involved in Gibberellin-Mediated Sugarcane Internode Growth.

Internode elongation is an important trait in sugarcane as it affects the sugarcane yield. Gibberellin (GA) is a key modulator of internode elongation in sugarcane. Understanding the gene expression features of GA-mediated internode elongation has both scientific and practical significance. This study aimed to examine the transcriptomic changes in the internode elongation of sugarcane following GA treatment. Eighteen cDNA libraries from the internode tissues on days of 0, 3, and 6 in control and GA treatment groups were sequenced and their gene expression were studied. RNA-seq analysis revealed 1,338,723,248 reads and 70,821 unigenes from elongating internodes of sugarcane. Comparative studies discovered a large number of transcripts that were differentially expressed in GA-treated samples compared to the control. Further analysis revealed that the differentially expressed genes were enriched in the metabolic process, one-carbon compound transport, and single-organism process. Kyoto Encyclopedia of Genes and Genomes pathway annotation showed significant enrichment in photosynthesis and plant hormone signal transduction, indicating its involvement in internode elongation. The function analysis suggested that metabolic pathways and biosynthesis of secondary metabolites, plant hormones, and cell wall components were enriched in the internodes of the GA-treated plants. The hub genes were identified, with the function of cellulose synthesis. The results of this study provide a global view of mRNA changes during sugarcane internode elongation and extend our knowledge of the GA-mediated cellular processes involved in sugarcane stem growth.

Polyethylenimine-Mediated CCR5 Gene Knockout Using Transcription Activator-Like Effector Nucleases.

CCR5 acts as one of the key coreceptors for human immunodeficiency virus infection, which leads to acquired immune deficiency syndrome. CCR5 gene knockout comes up as an alternative method for treatment of the disease. Transcription activator-like effector nuclease is a powerful gene editing tool characterized by the ease of design, high rates of cleavage activity, and the accessibility of all ranges of transcription activator-like effector nucleases. In this study, transcription activator-like effector nuclease plasmids specifically targeting to knock out CCR5 gene were designed, constructed and then transfected to Hela and HEK293T cell lines with the assistance of the well-established gene delivery carrier polyethylenimine. The transfection efficiency of polyethylenimine reached 50-60% at the optimized N/P ratio of 6/1. The genomic CCR5 sequencing results suggested an estimated knockout efficiency of around 50% under the optimized condition. Thus, CCR5 gene knockout was achieved in cell lines by the polyethylenimine-mediated transfection of transcription activator-like effector nuclease plasmids of interest. More efforts such as the improvement of transfection efficiency of gene delivery carrier could be made to achieve higher gene knockout efficiency of transcription activator-like effector nucleases.