Project description:The structural diversity and tunability of the capsid proteins (CPs) of various icosahedral and rod-shaped viruses have been well studied and exploited in the development of smart hybrid nanoparticles. However, the potential of CPs of the wide-spread flexuous filamentous plant viruses remains to be explored. Here, we show that we can control the shape, size, RNA encapsidation ability, symmetry, stability and surface functionalization of nanoparticles through structure-based design of CP from potato virus Y (PVY). We provide high-resolution insight into CP-based self-assemblies, ranging from large polymorphic or monomorphic filaments to smaller annular, cubic or spherical particles. Furthermore, we show that we can prevent CP self-assembly in bacteria by fusion with a cleavable protein, enabling controlled nanoparticle formation in vitro. Understanding the remarkable structural diversity of PVY CP not only provides possibilities for the production of biodegradable nanoparticles, but may also advance future studies of CP's polymorphism in a biological context.
Project description:Common transcriptional responses of Arabidopsis thaliana protoplasts transfected with turnip crinkle virus (TCV) , hibiscus chlorotic ringspot virus (HCRSV) and their coat protein mutants.
Project description:Transcriptional profiling during Arabidopsis seed coat development at 3 key developmental timepoints by using 2 mutant lines and their wild types. The data provides a globe view of seed coat development in arabidopsis can be used for identification of new gene candidates for seed coat development.
Project description:The strict anaerobe Clostridium difficile is an important nosocomial enteropathogen that has become the most common cause of antibiotic-associated diarrhea. The oxygen-resistant C. difficile spores play a central role in the infectious cycle, contributing to transmission, infection and recurrence. The spore surface layers, coat and exosporium, enable resistance of the spores to extreme physical and chemical stresses. Despite the critical importance of the spore in C. difficile infection, little is known about the mechanisms that orchestrate the assembly of its external layers. In this study, we identified and characterized a new C. difficile spore protein, named CotL, which is required for the assembly of the spore surface layers. The cotL gene was expressed in the mother cell compartment under the dual control of σE and σK. The CotL protein was localized in the C. difficile spore coat and cotL mutant spores had a major morphologic defect at the level of the coat/exosporium layers, as observed by transmission electron microscopy. Accordingly, spores of the cotL mutant contained a reduced amount of several proteins of the coat and exosporium, including CotB, CotE and CdeC. Additionally, cotL inactivation resulted in a defect in localization of late spore coat proteins in sporulating cells. Finally, spores of the cotL mutant were more sensitive to lysozyme and were impaired in germination. These defects are most likely associated with the structurally altered coat. Collectively, these results strongly suggest that CotL is a morphogenetic protein essential for the assembly of the spore coat in C. difficile.
Project description:Transgenic expression of viral proteins in natural host plants is a useful simplified system with the potential to understand the individual effect of each viral component. Transgenic expression of movement (MP) and a variant from coat protein (CPT42W) in tobacco, a TMV natural host, produces severe morphological changes, altered miRNAs accumulation and poor fertility. We used microarrays to characterize the gene expression changes caused by the co-expression of TMV capsid and movement proteins in Nicotiana tabacum comparing two isogenic lines MPxCPT42W and mpxcpT42W* (a line with both transgenes spontaneously silenced and with normal phenotype).
Project description:Transcriptional profiling during Arabidopsis seed coat development at 3 key developmental timepoints by using 2 mutant lines and their wild types. The data provides a globe view of seed coat development in arabidopsis can be used for identification of new gene candidates for seed coat development. 3 seed coat development stages, 4 lines (2 wild type + 2 mutants) of arabidopsis were sampled. 4 biological replicates.
Project description:The plant cell wall performs a number of essential functions including providing shape to many different cell types and serving as a defense against potential pathogens. The net pattern mutation creates breaks in the seed coat of soybean (Glycine max) because of ruptured cell walls. Using RNA-Seq, we examined the seed coat transcriptome from three stages of immature seed development in two pairs of isolines with normal or defective seed coat phenotypes due to the net pattern. The genome-wide comparative study of the transcript profiles of these isolines revealed 364 differentially expressed genes in common between the two varieties that were further divided into different broad functional categories. Genes related to cell wall processes accounted for 19% of the differentially expressed genes in the middle developmental stage of 100-200 mg seed weight. Within this class, the cell wall proline-rich and glycine-rich protein genes were highly differentially expressed in both genetic backgrounds. Other genes that showed significant expression changes in each of the isoline pairs at the 100-200 mg seed weight stage were xylem serine proteinase, fasciclin-related genes, auxin and stress response related genes, TRANSPARENT TESTA 1 (TT1) and other transcription factors. The mutant appears to shift the timing of either the increase or decrease in the levels of some of the transcripts. The analysis of these data sets reveals the physiological changes that the seed coat undergoes during the formation of the breaks in the cell wall.
Project description:Transcriptional analysis of stigmas was performed to identify molecules functioning in compatible pollination. Stigmas of A. thaliana Col-0 were collected (i) at 0 min or 15 min after pollination and (ii) before or at 15 min after pollen coat adhesion, and used for microarray analysis. Genes up-regulated after pollination and after pollen coat adhesion were identified. .