Mixed virus infection has increasingly become a problem in the production of Solanaceae crops in recent years; therefore, a fast and accurate detection method is needed. In this study, a novel triplex lateral flow immunoassay (LFA) strip assay was developed for the simultaneous detection of tobacco mosaic virus (TMV), tobacco vein banding mosaic virus (TVBMV), and potato virus Y (PVY). The limits of detection of this novel LFA strip reached 200 ppb (ng/ml), 1 ppm (µg/ml), and 2 ppm for TMV, PVY, and TVBMV particles, respectively. Importantly, no cross-reactivity was observed among TMV, TVBMV, and PVY or to a nontarget virus. When the assay was applied to suspected virus-infected tobacco, tomato, and potato samples collected from fields in Southwest China, samples of single or mixed virus infection were successfully identified. In conclusion, the triplex LFA strip assay provides a fast and easy to use on-site detection method for field epidemiological studies of TMV, TVBMV, and PVY, and for managing diseases that are caused by them.

Interferons (IFNs) are divided into 3 types (type I, type II, and type III) on the basis of sequence homology and functional properties. Recombinant IFNs have been approved by regulatory agencies in many countries for clinical treatment of hepatitis B, hepatitis C, and other diseases; these IFNs are mainly produced in microorganisms and mammalian cell systems. However, there are serious obstacles to the production of recombinant IFNs in microorganism systems; for example, the recombinant IFN may have different glycosylation patterns from the native protein, be present in insoluble inclusion bodies, be contaminated with impurities such as endotoxins and nucleic acids, have a short half-life in human blood, and incur high production costs. Some medicinal proteins have been successfully expressed in plants and used in clinical applications, suggesting that plants may also be a good system for IFN expression. However, there are still many technical problems that need to be addressed before the clinical application of plant-expressed IFNs, such as increasing the amount of recombinant protein expression and ensuring that the IFN is modified with the correct type of glycosylation. In this article, we review the classification of IFNs, their roles in antiviral signal transduction pathways, their clinical applications, and their expression in plant systems.

Owing to the economic value of its foliage, tobacco (Nicotiana tabacum) is cultivated all across the world. For the detection of genetically modified (GM) tobacco, there is a lack of universal standard material which ultimately limits the detection methods because the accuracy and comparability of the results cannot be ensured. Here, we prepared a reference plasmid pGMT27 for the detection of GM tobacco, which was 18,296bp in length harboring two of the tobacco endogenous and seven exogenous genes. By using qualitative PCR test for the nine genes, 10 copies were used for plasmid sensitivity. In the quantitative real-time PCR (qPCR) assays with pGMT27 as a calibrator, the reaction efficiencies for P-35S and NR were 101.427 and 98.036, respectively, whereas the limit of detection (LOD) and limit of quantification (LOQ) were 5 copies and 10 copies per reaction. For standard deviation (SD) and relative standard deviation (RSD) of the Ct values, the repeatability values were from 0.04 to 0.42 and from 0.18 to 1.29, respectively; and the reproducibility values were from 0.04 to 0.39 and from 0.18 to 1.14, respectively. For the unknown sample test, the average conversion factor (Cf) was 0.39, and the accuracy bias was from 15.55 to 1.93; for precision, the SD values ranged from 0.02 to 0.62, while RSD values were from 1.34 to 10.6. We concluded that using the pGMT27 plasmid as a calibrator provided a highly efficient transgenic detection method for flue-cured tobacco.

Plant virus‐based vectors are gaining significant attention as bioreactors for recombinant protein production due to their broad host range, robust expression levels and cost‐effectiveness; however, their practical utility is frequently constrained by severe viral pathogenicity. Notably, the utility of potato virus Y (PVY), the type member of the genus Potyvirus , is severely hampered by its elicitation of tobacco vein necrosis (TVN). Here, we demonstrate that a single synonymous substitution (AAA to AAG) at the K178 codon of P1 causes almost no TVN. Mechanistically, the P1‐AAG mutation attenuates the synergistic RNA silencing suppression (RSS) activity typically mediated by the P1/HC‐Pro complex. This functional impairment abrogates the virus‐induced upregulation of specific host microRNAs (miR6020, miR6164 and miR6021). Using this non‐necrotic PVY‐P1‐AAG vector, we engineered an optimised bioproduction platform. By integrating a GFP‐HRV3C fusion tag system with affinity purification and subsequent proteolytic cleavage, we achieved the high‐yield synthesis of recombinant human interferons (IFN‐α1b and IFN‐α2b) in Nicotiana benthamiana and Nicotiana tabacum ‘Xanthi’. Codon optimisation of the cargo genes further enhanced protein accumulation, achieving yields of up to 55.2 μg/g fresh leaf weight. Taken together, these results provide new insights into how synonymous substitutions influence potyviral pathogenicity and validate the symptomless P1‐AAG vector as a robust system for biomanufacturing value‐added proteins.