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Based on the idea of nodal cavity method, the simulation platform of constant deceleration braking system is built in Simulink. According to JKMD 4.5 × 4 mine hoist and its matching E141A constant ...

In this study, we demonstrate a novel pro-viral role for the Nicotiana benthamiana ARGONAUTE 1 (AGO1) in potyvirus infection. AGO1 strongly enhanced potato virus A (PVA) particle production and benefited the infection when supplied in excess. We subsequently identified the potyviral silencing suppressor, helper-component protease (HCPro), as the recruiter of host AGO1. After the identification of a conserved AGO1-binding GW/WG motif in potyviral HCPros, we used site-directed mutagenesis to introduce a tryptophan-to-alanine change into the HCPro (HCProAG) of PVA (PVAAG) and turnip mosaic virus (TuMVAG). AGO1 co-localization and co-immunoprecipitation with PVA HCPro was significantly reduced by the mutation suggesting the interaction was compromised. Although the mutation did not interfere with HCPro’s complementation or silencing suppression capacity, it nevertheless impaired virus particle accumulation and the systemic spread of both PVA and TuMV. Furthermore, we found that the HCPro-AGO1 interaction was important for AGO1’s association with the PVA coat protein. The coat protein was also more stable in wild type PVA infection than in PVAAG infection. Based on these findings we suggest that potyviral HCPro recruits host AGO1 through its WG motif and engages AGO1 in the production of stable virus particles, which are required for an efficient systemic infection., Author summary In the course of an infection viral proteins come regularly into contact with host factors. Knowledge of these virus-host interactions in plants is essential for understanding the progress of infections and for addressing challenges in the production of healthy plants, which is important for global food security. In this study we report that the potyviral Helper component proteinase (HCPro) recruits host ARGONAUTE1 protein and engages it in pro-viral functions. We found that the interaction of potato virus A HCPro with ARGONAUTE1 benefited the infection by promoting the stability and accumulation of virus particles. When HCPro was engineered to disrupt the interaction, we detected very few virus particles and observed that the mutated virus did not spread efficiently. Thus, we propose that the interaction between HCPro and ARGONAUTE1 has biological relevance as it is important for formation of stable particles and achieving optimal systemic infection.

Plant viral infection results in a multi-billion dollar economic loss worldwide each year. The use of genetic resistance is the most effective and sustainable approach to the control of plant viral diseases. However, owing to the lack of natural resistance genes, a single devastating viral pathogen often becomes a significant limiting factor in crop production. All plant viruses have a small viral genome that encodes a limited number of viral proteins. They must depend on host gene products (host factors) to complete their life cycle. Mutation, silencing or down-regulation of host factor gene(s) may lead to recessively inherited resistance to viruses. This is a major driving force for the molecular identification and functional characterization of host factors essential in virus infections. Potyviruses represent over 30% of all known plant viruses and constitute the largest plant virus group. Many agriculturally important viruses are potyviruses. In the last decade, several potyviral host factor genes including the well-known eIF4E or eIF(iso)4E gene have been molecularly identified. In this review, I will summarize research progress in molecular understanding of potyviral infection processes, and discuss manipulation of the identified host factors against potyviruses.

Cultured free round pearls are produced by implanting a spherical nucleus with a small piece of nacre-secreting mantle graft from a donor oyster into the gonad of a recipient oyster (host). To examine the possible contribution of host and donor oysters to the colouration of the harvested pearls, the CSE-1 Imaging and Color-Measuring System were used to quantitatively measure the L*a*b* values of donor and host shells and the produced pearls in Pinctada martensii. Results showed that the colour of pearls had significant positive correlation (r = 0.1–0.22, P = 0.00) with that of donors, but had no correlation with that of host oysters, thus convincingly confirmed the contribution of nacre colour of donor to the realization of pearl quality of colour. To further clarify the relationship between the donor and the pearl colour, the donors from pearls of good and poor colour quality were further compared and the results demonstrated the significant difference in L* values (P

The end of fully mechanized caving face is keystone and difficulty on protecting and managing the top. The effect on supporting the end of work face is very importment to mechanical and electrical machine, and very importment to workers' safety. The text analyze the problem of supporting the end at present, and Aiming at these problem, reach and manufact the fully mechanized caving face supporting system, then introducing the system's whole structure and control mode and key components particularly.

Transient expression via agroinfiltration and/or viral vectors has quickly emerged as the preferred expression system for plant-made recombinant proteins. Transient expression can serve as a valuable research tool for finding optimal expression parameters before tedious and time-consuming production of stable transgenic plants or it can be scaled up to commercial production scale with vacuum infiltration. This technology is poised to compete with conventional production systems, large-scale production facilities are currently available and others are in the process of development. This chapter will introduce background and rationale in development of transient expression systems in plants and summarize the latest developments and examples in this area.