Arabidopsis PDLP7 modulated plasmodesmata function is related to BG10-dependent glucosidase activity required for callose degradation.

The microdomains of plasmodesmata, specialized cell-wall channels responsible for communications between neighboring cells, are composed of various plasmodesmata-located proteins (PDLPs) and lipids. Here, we found that, among all PDLP or homologous proteins in Arabidopsis thaliana genome, PDLP5 and PDLP7 possessed a C-terminal sphingolipid-binding motif, with the latter being the only member that was significantly upregulated upon turnip mosaic virus and cucumber mosaic virus infections. pdlp7 mutant plants exhibited significantly reduced callose deposition, larger plasmodesmata diameters, and faster viral transmission. These plants exhibited increased glucosidase activity but no change in callose synthase activity. PDLP7 interacted specifically with glucan endo-1,3-ß-glucosidase 10 (BG10). Consistently, higher levels of callose deposition and slower virus transmission in bg10 mutants were observed. The interaction between PDLP7 and BG10 was found to depend on the presence of the Gnk2-homologous 1 (GnK2-1) domain at the N terminus of PDLP7 with Asp-35, Cys-42, Gln-44, and Leu-116 being essential. In vitro supplementation of callose was able to change the conformation of the GnK2-1 domain. Our data suggest that the GnK2-1 domain of PDLP7, in conjunction with callose and BG10, plays a key role in plasmodesmata opening and closure, which is necessary for intercellular movement of various molecules.

Bioinformatics and Experimental Analysis of the Prognostic and Predictive Value of the CHPF Gene on Breast Cancer.

Background: Recent studies in the United States have shown that breast cancer accounts for 30% of all new cancer diagnoses in women and has become the leading cause of cancer deaths in women worldwide. Chondroitin Polymerizing Factor (CHPF), is an enzyme involved in chondroitin sulfate (CS) elongation and a novel key molecule in the poor prognosis of many cancers. However, its role in the development and progression of breast cancer remains unclear. Methods: The transcript expression of CHPF in the Cancer Genome Atlas-Breast Cancer (TCGA-BRCA), Gene Expression Omnibus (GEO) database was analyzed separately using the limma package of R software, and the relationship between CHPF transcriptional expression and CHPF DNA methylation was investigated in TCGA-BRCA. Kaplan-Meier curves were plotted using the Survival package to further assess the prognostic impact of CHPF DNA methylation/expression. The association between CHPF transcript expression/DNA methylation and cancer immune infiltration and immune markers was investigated using the TIMER and TISIDB databases. We also performed gene ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis with the clusterProfiler package. Western blotting and RT-PCR were used to verify the protein level and mRNA level of CHPF in breast tissue and cell lines, respectively. Small interfering plasmids and lentiviral plasmids were constructed for transient and stable transfection of breast cancer cell lines MCF-7 and SUM1315, respectively, followed by proliferation-related functional assays, such as CCK8, EDU, clone formation assays; migration and invasion-related functional assays, such as wound healing assay and transwell assays. We also conducted a preliminary study of the mechanism. Results: We observed that CHPF was significantly upregulated in breast cancer tissues and correlated with poor prognosis. CHPF gene transcriptional expression and methylation are associated with immune infiltration immune markers. CHPF promotes proliferation, migration, invasion of the breast cancer cell lines MCF-7 and SUM1315, and is significantly enriched in pathways associated with the ECM-receptor interaction and PI3K-AKT pathway. Conclusion: CHPF transcriptional expression and DNA methylation correlate with immune infiltration and immune markers. Upregulation of CHPF in breast cancer promotes malignant behavior of cancer cells and is associated with poorer survival in breast cancer, possibly through ECM-receptor interactions and the PI3K-AKT pathway.

Extensive reticulate evolution within Fargesia (s.l.) (Bambusoideae: Poaceae) and its allies: Evidence from multiple nuclear markers.

Reticulate evolution resulting from hybridization and introgression has been recognized as a creative source of species and diversification in bamboos. Previous phylogenetic studies revealed that Fargesia (s.l.) (Fargesia and Yushania) was divided into the Fargesia spathe clade and the non-spathe clade. Interestingly, the Fargesia spathe clade may have originated from hybridization among other clades within Fargesia (s.l.). Understanding the hybrid origin of this clade requires a robust phylogenetic framework in which major clades within Fargesia (s.l.) are resolved. Here, we used three nuclear genes to reconstruct the evolutionary history of Fargesia (s.l.) and its allies to identify putative patterns in the origin of the Fargesia spathe clade and to examine the extent to which reticulate evolution has occurred at the interspecific level in bamboos. Bashania species form a clade with Fargesia (s.l.), which is further divided into Group I and Group II. The Fargesia spathe clade, the Alpine Bashania clade, and Fargesia yajiangensis comprise Group I, while the Bashania fargesii clade and the remaining Fargesia (s.l.) species form Group II. Incongruence between the current nuclear-based and previous plastid phylogenies demonstrate several possible hybridization events among Fargesia (s.l.) species and related taxa, which have given rise to the Fargesia spathe clade, the Phyllostachys clade, and the Ampelocalamus clade. We also detected several putative hybrid species of Fargesia (s.l.). Our results show that reticulate evolution has played a prominent role in Fargesia (s.l.) evolution, which could, in part, account for the taxonomic difficulty associated with Fargesia (s.l.) and the alpine bamboos. The study also underscores the importance of hybridization in the evolution of bamboos, at both intergeneric and intrageneric levels.

Identification and characterization of two arasin-like peptides in red swamp crayfish Procambarus clarkii.

Antimicrobial peptides (AMPs) are small effectors in host defense by directly targeting microorganisms or by indirectly modulating immune responses. In the present study, two arasin like AMPs, named as Pc-arasin1 and Pc-arasin2, were identified in red swamp crayfish Procambarus clarkii with sequence similarity to the arasins found in Hyas araneus. Both Pc-arasins consisted of signal peptide, N-terminal proline-rich region and C-terminal region containing four conserved cysteine residues. The similarity of two Pc-arasins was 44.44%, and Pc-arasin2 contained several additional residues in the N-terminus. Multiple alignment of arasin family suggested the conservation of the C-terminus and the variation of the N-terminus of Pc-arasins. Both AMPs were found hemocytes-specific, and the expression could be induced the challenge of bacteria, espeacially by the pathogenic bacterium Aeromonas hydrophila. Knockdown of each Pc-arasin expression by double strand RNA would suppress the host immunity against A. hydrophila, and the commercially synthetic Pc-arasins could rescue the knockdown consequence. Both synthetic peptide showed broad antimicrobial activity towards 3 Gram-positive bacterium and 3 Gram-negative bacterium, and the minimal inhibitory concentrations varied from 6.25 µM to 50 µM. These results presented new data about the sequence, expression and function of arasin family, and emphasized the role of this family in host immune response against bacterial pathogens. The characterization of Pc-arasins also provided potential of therapeutic agent development for disease control in aquaculture based on these two newly identified AMPs.