Lignin is a crucial component of plant cell walls, supporting plant growth by providing mechanical strength, aiding water transport, and enhancing resistance to pathogens. Despite extensive research on lignin biosynthesis as a renewable resource, understanding the transport and deposition of its monomers remains challenging. In this study, a novel precursor monomer was designed, SALK (alkyne-tagged sinapyl alcohol surrogate), for tracking and localizing lignin in flax cells, aiming to explore the in vivo lignification process. First, dehydrogenation polymer (DHP) of SALK was synthesized and successfully verified its biocompatibility. After click chemistry to label fluorescent dyes, incorporation of novel lignin monomers during the polymerization process was detected and imaged successfully. The results indicated that the chemical reporter could provide detailed localization information during polymerization. It was found that lignification in the bast fibers (R) cells and fiber tracheids (FT) cells of flax was different. FT cells closer to the pith showed higher maturity and lower lignification degree. While R cells, regardless of their proximity to the pith, show a relatively consistent lignification trend. At the single-cell level, lignin deposition initiates at cell corners and the middle lamella, followed by secondary cell wall, with the highest lignin content in the secondary wall of mature cells. The results of this work reveal the potential of chemical reporters in providing detailed insights into the in vivo lignification process, advancing the technology for studying the formation and function of plant cell walls.
More than 80 % of the potash fertilizer globally is produced by the froth flotation process. Octadecylamine (ODA) and 4-dodecylmorpholine (DMP), the most commonly used flotation collectors, are discharged into salt lakes, posing a hazard to human health and environmental safety. This study investigated ODA and DMP degradation processes under ultraviolet radiation. The experimental results showed that the degradation efficiency of ODA and DMP of 10 ppm reached 100 % within 60 min of UV irradiation in the brine. In contrast, complete degradation in pure water required 80 and 90 min for ODA and DMP, respectively. Notably, salt ions significantly accelerated the degradation of these organic amines compared to pure water. The nitrogen element in both compounds was ultimately converted into ammonium (NH₄⁺). Total organic carbon (TOC) measurements and gas chromatography-mass spectrometry (GC-MS) analyses revealed that the degradation process initiated with the cleavage of C-N bonds, followed by the breakdown of carbon chains. Based on GC-MS data, potential degradation pathways and mechanisms for ODA and DMP were proposed. The possible degradation pathways and mechanisms of ODA and DMP were proposed following GC-MS analyses. Field experiments and the detection of organic compounds in actual brines further validated the photodegradation reactions and mechanisms of the organic amines. This work guides the use of flotation agents and pollution control to produce potassium salts in salt lakes and aids in understanding the degradation processes of organic amines in natural environments.
危险品化学品经营许可证（带存储）