Biosynthetic labeling with 3-O-propargylcaffeyl alcohol reveals in vivo cell-specific patterned lignification in loquat fruits during development and postharvest storage

Lignification is a major cell wall modification that often results in the formation of sophisticated subcellular patterns during plant development or in response to environmental stresses.Precise localization of the spatiotemporal deposition of lignin is of great importance for revealing the lignification regulatory mechanism of individual cells.In loquat fruits,lignification typically increases the flesh lignin content and firmness,reducing their edibility and processing quality.However,the precise localization of the spatiotemporal active zones of lignification inside loquat fruit flesh remains poorly understood,and little is known about the contribution of patterned lignification to cell wall structure dynamics and the subsequent fruit-quality deterioration.Here,we performed an emerging bioorthogonal chemistry imaging technique to trace the in vivo patterned lignification dynamics in cells of loquat fruit flesh during development and storage.In developing fruits,lignified cells(LCs)and vascular bundles(VBs)were the zones of active lignification,and ring-like LCs deposited lignin at both the inner wall layer and the outer periphery sides.The domino effect of the generation of LCs was preliminarily visualized.In mature fruits,the newly formed lignin in the flesh of fruits during storage was specifically deposited in the corners and middle lamellae of parenchyma cells surrounding the VBs,resulting in the development of a reticular structure.Based on the findings,distinct spatiotemporal patterned lignification modes for different flesh cells in loquat fruits were proposed.These findings provide loquat lignification dynamics together with spatiotemporal data that can improve our understanding of the lignification process in planta.

Research Progress on Saussurea Tibetan Medicine-Taking Saussurea stella Maxim. for Example

Saussurea plants have a long history of being used for disease prevention and control in Tibetan medicine, and the species have gradually changed along with the development of history. Saussurea is mainly effective in wind-expelling, blood circulation, spasmolysis, pain relief, heat-clearing and detoxification. Characteristics, major chemical constituents and pharmacological studies of Saussurea stella Maxim. were summarized in this review based on the utilization of Saussurea medicinal plants in Tibetan areas, with the aim to provide adequate theoretical bases and references for exploring the further medicinal value and development and utilization of S. stella .

Reaction between tetravalent cerium ion and chloride ion and effect of thiourea using cyclic voltammetry

To monitor the reaction between Ce^(4+) ion and Cl-ion at the electron level,an electrochemical experiment was designed in this work.Herein,the intermediate and final products that may be produced during the redox reaction are directly tracked by using cyclic voltammetry,and the influences of Ce^(4+) ion concentration,temperatu re and F-ion on the reduction peak potential of Ce^(4+) ion were investigated.The results show that Ce^(4+) ion reacts with Cl-ion through an irreversible reaction without any intermediate products,and the rate-determining step of the reaction is diffusion during the electrode reaction.The effects of temperature(20-40℃) and Ce^(4+) ion concentration(0.04-0.12 mol/L) on the reduction peak pote ntial of Ce^(4+) ion can be ignored,but the higher the molar ratio of F-to Ce^(4+)(0-3 mol/mol),the mo re easily the reduction of Ce^(4+) ion to Ce^(3+) ion occurs.Additionally,the Ce^(4+) ions are preferentially reduced by thiourea when thiourea is added in the HCl solution,and thiourea inhibits the oxidation of Cl-ions to Cl_(2) by forming a complex with Cl-ions.This work provides a theoretical basis for the role of thiourea in inhibiting Cl_(2) production and offers a new way to find new reductants.