Coupling of ultrasmall and small CoxP nanoparticles confined in porous SiO2 matrix for a robust oxygen evolution reaction

Rational design of electrocatalysts is important for a sustainable oxygen evolution reaction(OER).It is still a huge challenge to engineer active sites in multi-sizes and multi-components simultaneously.Here,a series of CoxP nanoparticles(NPs)confined in an SiO2matrix(SiO2/CoxP)is designed and synthesized as OER electrocatalysts.The phosphorization of the hydrolyzed Co-phyllosilicate promotes the formation of ultrasmall and small Co2P and CoP.These are firmly confined in the SiO2matrix.The coupling of multi-size and multi-component CoxP catalysts can regulate reaction kinetics and electron transfer ability,enrich the active sites,and eventually promote the intrinsic OER activity.The SiO2matrix provides abundant porous structure and oxygen vacancies,and these facilitate the exposure of active sites and improve conductivity.Because of the synergy and interplay of multisized/component CoxP NPs and the porous SiO2matrix,the unique SiO2/CoxP heterostructure exhibits low overpotential(293 m V@10 mA cm-2),and robust stability(decay 12 mV after 5000 CV cycles,97.4%of initial current after 100 h chronoamperometric)for the OER process,exceeding many advanced metal phosphide electrocatalysts.This work provides a novel tactic to design low-cost,simple,and highly efficient OER electrocatalysts.

PbEIL1 acts upstream of PbCysp1 to regulate ovule senescence in seedless pear

Numerous environmental and endogenous signals control the highly orchestrated and intricate process of plant senescence.Ethylene,a well-known inducer of senescence,has long been considered a key endogenous regulator of leaf and flower senescence,but the molecular mechanism of ethylene-induced ovule senescence has not yet been elucidated.In this study,we found that blockage of fertilization caused ovule abortion in the pear cultivar‘1913’.According to transcriptome and phytohormone content data,ethylene biosynthesis was activated by pollination.At the same time,ethylene overaccumulated in ovules,where cells were sensitive to ethylene signals in the absence of fertilization.We identified a transcription factor in the ethylene signal response,ethylene-insensitive 3-like(EIL1),as a likely participant in ovule senescence.Overexpression of PbEIL1 in tomato caused precocious onset of ovule senescence.We further found that EIL1 could directly bind to the promoter of the SENESCENCE-ASSOCIATED CYSTEINE PROTEINASE 1(PbCysp1)gene and act upstream of senescence.Yeast one-hybrid and dual-luciferase assays revealed the interaction of the transcription factor and the promoter DNA sequence and demonstrated that PbEIL1 enhanced the action of PbCysp1.Collectively,our results provide new insights into how ethylene promotes the progression of unfertilized ovule senescence.

CPPU may induce gibberellin-independent parthenocarpy associated with PbRR9 in‘Dangshansu’pear

Parthenocarpy is a valuable trait in self-incompatible plants,such as pear.N-(2-chloro-4-pyridyl)-N’-phenylurea(CPPU),a synthetic cytokinin analog,can induce parthenocarpy in pear(Pyrus spp.),but the mechanism of induction is unclear.To investigate the role of gibberellin in CPPU-induced parthenocarpy in pear,CPPU supplemented with paclobutrazol(PAC)was sprayed onto‘Dangshansu’pear.We found that the fruit set rate of pear treated with CPPU supplemented with PAC was identical to that in a CPPU-alone treatment group.In regard to cell development,CPPU mainly promoted hypanthium cell division and expansion,and PAC application had no influence on CPPU-induced cell development.RNA sequencing revealed that gibberellin 20 oxidase and gibberellin 3 oxidase genes were not differentially expressed following CPPU treatment.According to the analysis of fruit phytohormone content,the CPPU treatments did not induce gibberellin biosynthesis.These results suggest that CPPU-induced parthenocarpy may be gibberellin independent in‘Dangshansu’pear.After CPPU treatment,the indole acetic acid(IAA)content in fruit was significantly increased,and the abscisic acid(ABA)content was significantly decreased.Similarly,RNA sequencing revealed that many genes involved in the auxin and ABA pathways were significantly differentially expressed in the CPPU treatment groups;among them,indole-3-pyruvate monooxygenase(YUCCA)was significantly upregulated and 9-cis-epoxycarotenoid dioxygenase(NCED)was significantly downregulated.IAA and ABA may thus play important roles in CPPU-induced parthenocarpy.PbTwo-component response regulator9(PbRR9),PbYUCCA4,and PbNCED6 were then selected to further elucidate the mechanism of CPPU-induced parthenocarpy.A yeast one-hybrid assay indicated that PbRR9 can combine with the PbYUCCA4 and PbNCED6 promoters.Dual luciferase assays revealed that PbRR9 can promote and repress the activities of the PbYUCCA4 and PbNCED6 promoters,respectively.After the transient expression of PbRR9 in fruits,PbYUCCA4 expression was significantly upregulated,and PbNCED6 expression was significantly downregulated.This study uncovered a CPPU-induced parthenocarpy mechanism that is different from that in tomato.CPPU may upregulate PbYUCCA4 and downregulate PbNCED6 by upregulating PbRR9,thereby increasing IAA content and decreasing ABA content to ultimately induce parthenocarpy in‘Dangshansu’pear.However,because only a single time point was used and because‘botanical’and‘accessory’fruits have different structures,this conclusion is still preliminary.

Quality Analysis and Evaluation of Scylla paramamosain from Three Different Areas

[Objectives]The quality of Scylla paramammosain produced in Fujian,Sanmen and Shanghai were analyzed and evaluated.[Methods]Adult Scylla paramammosain from Fujian,Sanmen and Shanghai were separated for their muscles and gonads,which were analyzed for nutritional components.[Results]The muscle moisture content of S.paramammosain from Sanmen was significantly higher than those in S.paramammosain from Fujian and Shanghai.The muscle protein contents of S.paramammosain from the three regions ranked as Shanghai>Fujian>Sanmen(P<0.05).The muscles of S.paramammosain from Shanghai had the highest crude fat and crude ash contents.The moisture contents of the gonads of the S.paramammosain from the three regions had no significant differences.The protein contents of the gonads of S.paramammosain from the three regions ranked as Shanghai>Sanmen>Fujian(P<0.05).The S.paramammosain from Sanmen had the highest crude fat and crude ash contents in gonads.The contents of 17 amino acids detected in the muscles and gonads of S.paramammosain from the three different regions were different.The total amounts of total amino acids(TAA),essential amino acids(EAA)and flavor amino acids(FAA)in the muscles of S.paramammosain from Sanmen were significantly lower than those produced in Fujian and Shanghai(P<0.05),but the proportions of essential amino acids(EAA)and flavor amino acids were not significantly different.The proportion of EAA and FAA in the gonads of S.paramammosain produced in the three areas were significantly different(P<0.05).There were also differences in the fatty acid composition of the muscles and gonads of S.paramammosain from the three different regions.The proportion of EPA in the muscles of S.paramammosain from Fujian was higher than those of other two groups,but the differences were not significant;the proportion of DHA was significantly higher than those of other two groups,and the differences were significant(P<0.05);and the proportions of n3 PUFA in muscles of S.paramammosain produced in Fujian and Sanmen were significantly higher than that of S.paramammosain produced in Shanghai(P<0.05).The proportions of EPA,DHA and n6 PUFA in the gonads of S.paramammosain produced in Sanmen were significantly higher than those produced in Fujian and Shanghai(P<0.05),while the n3 PUFA was the highest in S.paramammosain produced in Fujian.The proportions of n6/n3 PUFA in S.paramammosain produced in the three different regions were significantly different(P<0.05).In summary,it could be seen that the nutritional composition of S.paramammosain produced in different regions has its own characteristics.[Conclusions]This study provides basic data for the establishment of quality evaluation standards for S.paramammosain,and provides a new perspective for the evaluation of breeding models.

Application of a recombinant replicase to localize the Trionyx sinensis hemorrhagic syndrome virus and evaluate its effects on antiviral genes of T.sinensis

Trionyx sinensis Hemorrhagic Syndrome Virus(TSHSV)is an arterivirus newly discovered in Chinese softshell turtles.Little is known about the effect of antibodies against the virus or the distribution of the virus in different organs of infected turtles.In this study,a partial protein of TSHSV-HP4 was produced using a prokaryotic expression system,and its polyclonal antibody was generated.The polyclonal antibody was confirmed by western blot and dot enzyme-linked immunosorbent assay(dot-ELISA).The distribution of TSHSV in different organs of T.sinensis was examined by immunohistochemistry(IHC)and the expression of immune-related genes was analyzed using quantitative real-time polymerase chain reaction(qRT-PCR).The results indicated that the recombinant TSHSV-HP4 protein was successfully expressed,and the generated polyclonal antibody showed specific binding to viral particles in the lung tissues of infected turtles.The IHC assay indicated that the virus was highly localized in various cells,including intestinal lymphocytes,enterocytes,kidney epithelial cells,spleen cells,lung macrophages,and cardiomyocytes.The qRT-PCR analysis revealed that TSHSV was detected in all organs tested,including the lungs,liver,kidneys,spleen,and heart.The numbers of viral mRNA copies in lung and heart tissues were significantly higher in the virus-antibody group than in the virus group.The interferonstimulated genes(ISGs),myxovirus resistance protein 2(MX2)and radical S-adenosyl methionine domain containing 2(RSAD2)were highly upregulated in all groups of infected turtles.Antibody-dependent enhancement(ADE)seemed to occur after stimulation by the polyclonal antibody,because significantly greater expression of the two genes was detected in the virus-antibody group than in the virus group.Overall,these results are important in understanding the cell localization of TSHSV and the immune response of infected turtles.