PbGIF1 promoting cell-proliferation in pear fruit is transcriptionally activated by Pb RR1

As a cell proliferation regulator involved in wide biological processes in plants,GRF-INTERACTING FACTOR(GIF)controls different tissues development.However,whether GIF participates in fruit development remains unclear.According to transcriptome data,we identified PbGIF1was highly expressed during fruit development in cytokinins induced parthenocarpy pear.In the present study,the biofunction of PbGIF1 was initially verified.Overexpression of PbGIF1 promoted fruit size of transgenic tomato.The size of flesh fruit was not affected by cell expansion but the cell proliferation was promoted by overexpressing Pb GIF1.The accelerated cell proliferation process was also observed in PbGIF1-overexpressed transgenic pear fruit calli.The transcriptional regulation of cytokinins on PbGIF1 was further confirmed by exogenous CPPU treatments in pear fruitlets.To investigate the underlying mechanism,the cytokinins-responded factor,PbRR1,was further focused on.The results of Yeast-one-hybrid assay suggested that PbRR1 can bind to the promoter sequence of PbGIF1.The transcriptional activation of PbRR1 on PbGIF1 was also confirmed by Dual-Luciferase assays.Taken together,the results showed that cytokinins control pear fruit development via the transcriptional activation of PbGIF1 by PbRR1.

Histological, hormonal and transcriptomic reveal the changes upon gibberellin-induced parthenocarpy in pear fruit

Phytohormones play crucial roles in fruit set regulation and development.Here,gibberellins(GA4+7),but not GA3,induced pear parthenocarpy.To systematically investigate the changes upon GA4+7 induced pear parthenocarpy,dynamic changes in histology,hormone and transcript levels were observed and identified in unpollinated,pollinated and GA4+7-treated ovaries.Mesocarp cells continued developing in both GA4+7-treated and pollinated ovaries.In unpollinated ovaries,mesocarp cells stopped developing 14 days after anthesis.During fruit set process,GA4+7,but not GA1+3,increased after pollination.Abscisic acid(ABA)accumulation was significantly repressed by GA4+7 or pollination,but under unpollinated conditions,ABA was produced in large quantities.Moreover,indole-3-acetic acid biosynthesis was not induced by GA4+7 or pollination treatments.Details of this GA–auxin–ABA cross-linked gene network were determined by a comparative transcriptome analysis.The indole-3-acetic acid transport-related genes,mainly auxin efflux carrier component genes,were induced in both GA4+7-treated and pollinated ovaries.ABA biosynthetic genes of the 9-cis-epoxycarotenoid dioxygenase family were repressed by GA4+7 and pollination.Moreover,directly related genes in the downstream parthenocarpy network involved in cell division and expansion(upregulated),and MADS-box family genes(downregulated),were also identified.Thus,a model of GA-induced hormonal balance and its effects on parthenocarpy were established.

PbGA2ox8 induces vascular-related anthocyanin accumulation and contributes to red stripe formation on pear fruit

Fruit with stripes,which are generally longitudinal,can occur naturally,but the bioprocesses underlying this phenomenon are unclear.Previously,we observed an atypical anthocyanin distribution that caused red-striped fruit on the spontaneous pear bud sport“Red Zaosu”(Pyrus bretschneideri Rehd.).In this study,comparative transcriptome analysis of the sport and wild-type“Zaosu”revealed that this atypical anthocyanin accumulation was tightly correlated with abnormal overexpression of the gene-encoding gibberellin(GA)2-beta-dioxygenase 8,PbGA2ox8.Consistently,decreased methylation was also observed in the promoter region of PbGA2ox8 from“Red Zaosu”compared with“Zaosu”.Moreover,the GA levels in“Red Zaosu”seedlings were lower than those in“Zaosu”seedlings,and the application of exogenous GA4 reduced abnormal anthocyanin accumulation in“Red Zaosu”.Transient overexpression of PbGA2ox8 reduced the GA4 level and caused anthocyanin accumulation in pear fruit skin.Moreover,the presence of red stripes indicated anthocyanin accumulation in the hypanthial epidermal layer near vascular branches(VBs)in“Red Zaosu”.Transient overexpression of PbGA2ox8 resulting from vacuum infiltration induced anthocyanin accumulation preferentially in calcium-enriched areas near the vascular bundles in pear leaves.We propose a fruit-striping mechanism,in which the abnormal overexpression of PbGA2ox8 in“Red Zaosu”induces the formation of a longitudinal array of anthocyanin stripes near vascular bundles in fruit.

Quadrupole-Linear Ion Trap Tandem Mass Spectrometry System for Clinical Biomarker Analysis

The accurate and efficient measurement of small molecule disease markers for clinical diagnosis is of great importance.In this study,a quadrupole-linear ion trap(Q-LIT)tandem mass spectrometer was designed and built in our laboratory.Target precursor ions were first selected in the quadrupole,and then injected,trapped,and fragmented simultaneously in the linear ion trap(LIT)to reduce the space charge effect,enrich the target product ions,and promote sensitivity.The targeted analytes were measured with selected reaction monitoring using a positive scan mode with electrospray ionization(ESI).Ions with a mass-to-charge ratio(m/z)ranging from 195 to 2022 were demonstrated.When scanning at 1218amu.s^(-1),unit resolution and an accuracy of higher than m/z 0.28 was obtained for m/z up to 2000.The dimensionless Mathieu parameter(q)value used in this study was 0.40 for collision-induced dissociation(CID),which was activated by resonance excitation.And an overall CID efficiency of 64%was achieved(activation time,50 ms).Guanidinoacetic acid(GAA)and creatine(CRE)were used as model compounds for small molecule clinical biomarkers.The limits of quantification were 1.0 and 0.2 nmol.L^(-1)for GAA and CRE,respectively.A total of 77 actual samples were successfully analyzed by the home-built ESI-Q-LIT tandem mass spectrometry system.The developed method can reduce matrix interference,minimize space charge effects,and avoid the chromatographic separation of complex samples to simplify the pretreatment process.This novel Q-LIT system is expected to be a good candidate for the determination of biomarkers in clinical diagnosis and therapeutics.

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.

图形–背景理论视角下的微博新闻语篇分析—以特朗普移民令事件报道为例

在微博新闻语篇的分析过程中,通常的批评话语分析虽然能够有效地揭示其语篇、权利以及意识形态之间的关系,但认知语言学的理论成果更加有利于对其进行更深层次的解读。本文通过借助认知语言学中的图形–背景理论,对特朗普移民禁令事件揭露者的几篇新闻进行了深入分析,揭示出微博新闻语篇中意识形态的微妙不同,以及它们是如何对读者产生影响的。

Competition between anthocyanin and kaempferol glycosides biosynthesis affects pollen tube growth and seed set of Malus

Flavonoids play important roles in regulating plant growth and development.In this study,three kaempferol 3-O-glycosides were identi fi ed and mainly accumulated in fl owers but not in leaves or fruits of Malus.In Malus,fl ower petal color is normally white,but some genotypes have red fl owers containing anthocyanin.Anthocyanin biosynthesis appears to be in competition with kaempferol 3-O-glycosides production and controlled by the biosynthetic genes.The white fl ower Malus genotypes had better-developed seeds than the red fl ower genotypes.In fl owers,the overexpression of MYB10 in Malus domestica enhanced the accumulation of anthocyanin,but decreased that of kaempferol 3-O-glycosides.After pollination the transgenic plants showed slower pollen tube growth and fewer developed seeds.Exogenous application ofdifferent fl avonoid compounds suggested that kaempferol 3-O-glycosides,especially kaempferol 3-O-rhamnoside,regulated pollen tube growth and seed set rather than cyanidin or quercetin 3-O-glycosides.It was found that kaempferol 3-O-rhamnoside might regulate pollen tube growth through effects on auxin,the Rho of plants(ROP)GTPases,calcium and the phosphoinositides signaling pathway.With the inhibition of auxin transport,the transcription levels of Heat Shock Proteins(HSPs)and ROP GTPases were downregulated while the levels were not changed or even enhanced when blocking calcium signaling,suggesting that HSPs and ROP GTPases were downstream of auxin signaling,but upstream of calcium signaling.In summary,kaempferol glycoside concentrations in pistils correlated with auxin transport,the transcription of HSPs and ROP GTPases,and calcium signaling in pollen tubes,culminating in changes to pollen tube growth and seed set.

基于改进模板匹配的晶圆划切算法

当前国内晶圆自动划切的工业应用中,主要采用基于灰度的模板匹配方法,但其计算量大、划切效率较低。本文提出一种改进的基于几何边缘的模板匹配算法,通过Canny边缘检测生成合适的边缘模板,计算模板边缘曲线的梯度方向作为匹配信息进行相似度计算,采用相似度阈值判断优化搜索策略,然后在图像金字塔最顶层进行粗遍历匹配获得潜在匹配目标,逐层匹配直到最底层,以达到对传统的几何模版匹配算法进行加速的目的。实验表明,该方法具有较高的鲁棒性,对于目标均匀或非均匀变化的光照、部分遮挡的情况可以得到良好的匹配效果,而且算法在保证精度的同时可以满足实时性要求,适用于晶圆图像自动划切的工业应用。

Liquid-phase epitaxial layer by layer brushing fabrication of metalorganic frameworks films

Development of metal-organic framework(MOF)films is of great importance to expand their applications.Herein,we report a facile and universal method of liquid-phase epitaxial(LPE)layer by layer(LBL)brushing approach for fabricating MOF films on various substrates in a high-throughput fashion.This MOF films preparation method offers a great prospective to cost-effectively construct films with short preparation time and little reagent consumption.Moreover,this LBL brushing approach has been implemented successfully to assemble various MOF films,including HKUST-1,zeolitic imidazolate framework-8(ZIF-8),Cu(bdc),and Cu_(2)(L)_(2)P(L=bdc,ndc,and cam;P=dabco and bipy).Afterwards,the classic MOF HKUST-1 and ZIF-8 films were grown on sensor chip electrode and porous fiber support for good volatile organic compounds(VOCs)selective sensing and water purification applications.This study demonstrates that this LBL brushing preparation method can be employed to synthesize various MOF films with a variety of characteristics to realize their sensing and separation applications.

层层喷雾法制备表面配位金属-有机框架薄膜及其应用

作为新型晶体材料,金属-有机框架(MOFs)因具有比表面积大、孔隙率高、结构多样等特点而受到人们的广泛关注.将其组装成MOFs薄膜可以极大地拓展其在光电池、催化、二氧化碳还原、储存和分离等领域的应用.本文介绍了液相外延喷雾法层层组装MOFs薄膜的方法,并阐述了该方法制备的MOFs薄膜在选择性吸附与分离、催化、识别及光电器件方面的应用.最后,对相关领域的研究进行了展望.

螺旋铜-卟啉框架纳米阵列用于高效的二氧化碳电还原

金属-有机框架(MOF)因其高的比表面积、可调的孔道结构等特点,近年来在电催化二氧化碳还原领域受到了广泛的关注.本文中,我们首次采用牺牲模板法在Cu(OH)_(2)纳米阵列上生长具有螺旋形貌的铜-卟啉基MOF CuTCPP(H-Cu TCPP@Cu(OH)_(2)),并研究了其电催化二氧化碳还原性能.电催化性能显示,在-1.6 V vs.Ag/Ag^(+)电势下,HCu TCPP@Cu(OH)_(2)表现出二氧化碳还原成乙酸的高效性能,其法拉第效率高达26.1%,并优于非螺旋Cu TCPP(n H-Cu TCPP@Cu(OH)_(2))(19.8%).这是因为螺旋MOF纳米阵列具有更有效的催化空间并提供了更多催化活性位点.此外,原位红外光谱证实了H-Cu TCPP@Cu(OH)_(2)对一氧化碳具有更强的线性吸附,因此具有更高的乙酸选择性.这项工作不仅开发了新型螺旋纳米材料,也为提高电催化二氧化碳还原性能提供了一种新的途径.

Tunable chiroptical application by encapsulating achiral lanthanide complexes into chiral MOF thin films

Chiral metal-organic frameworks(chirMOFs)have been widely considered on enantioselective adsorption/separation,asymmetric catalysis,biological and nonlinear optical applications.However,chirMOFs are facing a great challenge in development of chiroptical thin films with circularly polarized luminescence(CPL)property.Here,we first report CPL thin films by encapsulating achiral lanthanide complexes Ln(acac)_(3)(Ln=Eu_(a)Tb_(b)Gd_(c))into the pores of surface-coordinated chirMOF thin films(SURchirMOF)[Zn_(2)(cam)_(2)dabco]_(n) with layer by layer(Ibl)encapsulation strategy.Due to the unique combination of chiral porous MOF and adjustable luminescent complexes in the host-guest thin films,the obtained Ln(acac)_(3)@SURchirMOF possess strong and tunable CPL property with high dissymmetry factors.The compared CPL and fluorescent lifetime results show that the advantage of this preparation strategy can effectively achieve energy transfer from Ln(acac)_(3) to SURchirMOF,resulting in an excellent CPL performance.This study not only provides a novel strategy to develop new types of chiral thin films but also offers an efficient approach for tunable chiroptical applications.

Layer-by-Layer Grafting Dye on Chiral MOF Thin Films for Circularly Polarized Luminescence

Metal-organic frameworks with chiral feature(chirMOFs) are attracting great attention on circularly polarized luminescence(CPL). However, developing new efficient strategy to achieve or improve CPL properties is an urgent task. Herein, new chiral MOF thin films prepared by liquid-phase epitaxial layer by layer(lbl) growth method(SURchirMOF) are composed of D-or L-camphorate(D/Lcam) and aminopyrazine(Pr-NH)by using liquid phase epitaxial layer by layer(lbl) method. The resulted Zn(D/Lcam)PrNHSURchirMOF shows strong chirality and luminescence but weak CPL emission at 390 nm. After lbl modifying a dye molecule FluoresceinIsothiocyanate(FITC), the chiroptical Zn(D/Lcam)Pr-NH-FITC SURchirMOFs with ~7 times CPL signal improvement and ~3 times glum value amplification are obtained. This work provides a new strategy to develop chiral MOF thin films for CPL improvement using lbl grafting approach.