Methylisothiazolinone pollution inhibited root stem cells and regeneration through auxin transport modification in Arabidopsis thaliana.

Methylisothiazolinone (MIT) is a widely used preservative and biocide to prevent product degradation, yet its potential impact on plant growth remains poorly understood. In this study, we investigated MIT's toxic effects on Arabidopsis thaliana root growth. Exposure to MIT significantly inhibited Arabidopsis root growth, associated with reduced root meristem size and root meristem cell numbers. We explored the polar auxin transport pathway and stem cell regulation as key factors in root meristem function. Our findings demonstrated that MIT suppressed the expression of the auxin efflux carrier PIN1 and major root stem cell regulators (PLT1, PLT2, SHR, and SCR). Additionally, MIT hindered root regeneration by downregulating the quiescent center (QC) marker WOX5. Transcriptome analysis revealed MIT-induced alterations in gene expression related to oxidative stress, with physiological experiments confirming elevated reactive oxygen species (ROS) levels and increased cell death in root tips at concentrations exceeding 50 µM. In summary, this study provides critical insights into MIT's toxicity on plant root development and regeneration, primarily linked to modifications in polar auxin transport and downregulation of genes associated with root stem cell regulation.

Metabolome and transcriptome analyses identify the characteristics and expression of related saponins of the three genealogical plants of bead ginseng.

Objective: The classification and clinical usage of the different species of bead ginseng are often confused. Therefore, we conducted an integrated metabolomics and transcriptome analysis of three main species of Panax, including Panax japonicas, Panax pseudoginseng, and Panax pseudo-ginseng var. elegantior. Methods: A broad metabolome and transcriptome analysis for three origins of bead ginseng plants was performed using UPLC-ESI-MS/MS, RNA sequencing and annotation, and bioinformatic analysis of transcriptome data. Results: The levels of 830 metabolites were determined. A total of 291 differentially accumulated metabolites (DAMs) between Panax pseudo-ginseng var. elegantior and Panax japonicas (Group A), with 73 upregulated and 218 downregulated. A total of 331 DAMs (110 upregulated and 221 downregulated) were found between Panax pseudoginseng and Panax japonicas (group B). There were 160 DAMs (102 up-regulated and 58 down-regulated) between Panax pseudoginseng and Panax pseudo-ginseng var. elegantior (group C). In addition, RNA sequencing was performed in the above three ways. A total of 16,074 differential expression genes (DEGs) were detected between Group A, in which 7,723 genes were upregulated and 8,351 genes were downregulated by RNA sequencing. Similarly, 15,705 genes were differentially expressed between group B, in which 7,436 genes were upregulated and 8,269 genes were downregulated. However, only 1,294 genes were differentially expressed between group C, in which 531 genes were upregulated and 763 genes were downregulated. We performed differential gene analysis on three groups of samples according to the Venn diagram and found that 181 differential genes were present. A total of 3,698 and 2,834 unique genes were in groups A and B, while 130 unique genes were in group C. Conclusions: This study provides metabolome and transcriptome information for three bead ginseng plants. The analysis of the metabolite content showed differences in the attributes of the three bead ginseng, contained mainly flavonoids, phenolic acids as well as terpenes.

Disentangling the activity-selectivity trade-off in catalytic conversion of syngas to light olefins.

Breaking the trade-off between activity and selectivity has been a long-standing challenge in the field of catalysis. We demonstrate the importance of disentangling the target reaction from the secondary reactions for the case of direct syngas conversion to light olefins by incorporating germanium-substituted AlPO-18 within the framework of the metal oxide-zeolite (OXZEO) catalyst concept. The attenuated strength of the catalytically active Brønsted acid sites allows enhancing the targeted carbon-carbon coupling of ketene intermediates to form olefins by increasing the active site density while inhibiting secondary reactions that consume the olefins. Thus, a light-olefins selectivity of 83% among hydrocarbons and carbon monoxide conversion of 85% were obtained simultaneously, leading to an unprecedented light-olefins yield of 48% versus current reported light-olefins yields of ≤27%.

Effect of Wood's anomalies on the profile of extraordinary transmission spectra through metal periodic arrays of rectangular subwavelength holes with different aspect ratio.

The extraordinary transmission through silver film perforated with rectangular hole array with different aspect ratio was investigated. It was found that when the aspect ratio exceeded 7, the propagating surface plasmon polaritons (SPPs) transformed to localized resonance mode. The role of the Wood's anomaly on the shape of the transmission spectrum is investigated. By designing the rectangular hole arrays in a rectangular lattice, the Wood's anomaly can be shifted far apart from the transmission peak, the real localized resonance peak wavelength was identified and fitted well with the theoretical calculation using a simplified transmission-line model.

Reflection and emission properties of an infrared emitter.

The reflection and emission properties of an infrared emitter, which is a plasmonic multilayer structure consisting of a relief metallic grating, a waveguide layer, and a metallic substrate are investigated both experimentally and theoretically. A localized surface plasmon polariton (SPP) mode which is angular-independent in almost the full range of incident angles is observed. The thermal emission of this structure is also measured. It is found that the emission peak coincides with the angular-independent localized SPP mode. In addition, the emission spectrum of the plasmonic emitter can be predicted by investigating the reflectance spectrum.