pUGTdb:A comprehensive database of plant UDP-dependent glycosyltransferases

Dear Editor,Plant UDP-dependent glycosyltransferases(UGTs),belonging to the carbohydrate-active enzyme glycosyltransferase 1 family(Louveau and Osbourn,2019),not only play important roles in adaptation to various environments(Cai et al.,2020;Pastorczyk-Szlenkier and Bednarek,2021)but also endow plant natural products with great pharmaceutical and ecological significance(Margolin et al.,2020).In recent years,an increasing number of plant UGTs have been characterized to function in the biosynthesis of many bioactive compounds such as ginsenosides(Wei et al.,2015),breviscapine(Liu et al.,2018),and rubusoside(Xu et al.,2022).

Optimal configuration of distributed power flow controller to enhance system loadability via mixed integer linear programming

The increase of energy consumption has caused power systems to operate close to the limit of their capacity.The distributed power flow controller(DPFC),as a new member of distributed flexible AC transmission systems,is introduced to remove this barrier.This paper proposes an optimal DPFC configuration method to enhance system loadability considering economic performance based on mixed integer linear programming.The conflicting behavior of system loadability and DPFC investment is analyzed and optimal solutions are calculated.Thereafter,the fuzzy decision-making method is implemented for determining the most preferred solution.In the most preferred solution obtained,the investment of DPFCs is minimized to find the optimal number,locations and set points.Simulation results on the IEEERTS79 system demonstrate that the proposed method is effective and reasonable.

Coupled relationships among anammox,denitrification, and dissimilatory nitrate reduction to ammonium along salinity gradients in a Chinese estuarine wetland

Salinization in estuarine wetlands significantly alters the balance between their nitrogen(N)removal and retention abilities but these processes have not yet been characterized effectively.In the present study,the potential rates of sediment denitrification,anaerobic ammonium oxidation(anammox),and dissimilatory nitrate reduction to ammonium(DNRA)were mapped using N isotope tracing methods along salinity gradients across the Yellow River Delta wetland(YRDW)in China.The contribution of anammox to total dissimilatory N transformations in YRDW was merely 6.8%,whereas denitrification and DNRA contributed 52.3%and 40.9%,respectively.The potential rate of denitrification(5.82μmol/kg/h)decreased significantly along salinity gradients and markedly exceeded DNRA potential rate(2.7μmol/kg/h)in fresh wetlands,but was lower than that of DNRA in oligohaline wetlands(3.06 and 3.18μmol/kg/h,respectively).Moreover,a significantly positive relationship between salinity and DNRA/denitrification was obeserved,indicating that increased salinity may favor DNRA over denitrification.Furthermore,total sulfur(TS)content and ratio of total organic carbon to total nitrogen(C/N)increased with the salinity gradient and showed evident positive relationships with the DNRA/denitrification ratio.In this study,we proved that increased salinization resulted in the dominance of DNRA over denitrification,possible through the addition of S and alteration of the C/N in estuarine wetlands,leading to increased N retention in estuarine wetlands during salinization,which would enhance the eutrophication potential within wetlands and in downstream ecosystems.

The influence of pulsed parameters on the damage of a Darlington transistor

Theoretical research on the heat accumulation effect of a Darlington transistor induced by high power microwave is conducted,and temperature variation as functions of pulse repetitive frequency（PRF）and duty cycle（DC）are studied.According to the distribution of the electronic field and the current density in the Darlington transistor,the research of the damage mechanism is carried out.The results show that for repetitive pulses with the same pulse widths and different PRFs,the value of temperature variation increases with PRF increases,and the peak temperature has almost no change when PRF is lower than 200 k Hz;while for the repetitive pulses with the same PRF and different pulse widths,the larger the pulse width is,the greater temperature variation varies.The response of the peak temperature caused by a single pulse demonstrates that there is no temperature variation when the rising time is much shorter than the falling time.In addition,the relationship between the temperature variation and the time during the rising edge time as well as that between the temperature variation and the time during the falling edge time are obtained utilizing the curve fitting method.Finally,for a certain average power,with DC increases the value of temperature variation decreases.

PCPD:Plant cytochrome P450 database and web-based tools for structural construction and ligand docking

Plant cytochrome P450s play key roles in the diversification and functional modification of plant natural products.Although over 200,000 plant P450 gene sequences have been recorded,only seven crystalized P450 genes severely hampered the functional characterization,gene mining and engineering of important P450s.Here,we combined Rosetta homologous modeling and MD-based refinement to construct a high-resolution P450 structure prediction process(PCPCM),which was applied to 181 plant P450s with identified functions.Furthermore,we constructed a ligand docking process(PCPLD)that can be applied for plant P450s virtual screening.10 examples of virtual screening indicated the process can reduce about 80%screening space for next experimental verification.Finally,we constructed a plant P450 database(PCPD:http://p450.biodesign.ac.cn/),which includes the sequences,structures and functions of the 181 plant P450s,and a web service based on PCPCM and PCPLD.Our study not only developed methods for the P450-specific structure analysis,but also introduced a universal approach that can assist the mining and functional analysis of P450 enzymes.