Whole-genome characterization of CKX genes in Prunus persica and their role in bud dormancy and regrowth

Bud dormancy is a complex physiological process of perennial woody plants living in temperate regions,and it can be affected by various phytohormones.Cytokinin oxidase/dehydrogenases(CKXs)are a group of enzymes essential for maintaining cytokinin homeostasis,yet a comprehensive analysis of these enzymes in peach remains lacking.Here,a total of 51 CKX members from different species,including six from peach,eleven from apple,nine from poplar,seven from Arabidopsis,eight from strawberry,and ten from rice,were identified using the Simple HMM Search tool of TBtools and a BLASTP program and classified into four groups using phylogenetic analysis.Conserved motif and gene structure analysis of these 51 CKX members showed that 10 conserved motifs were identified,and each CKX gene contained at least two introns.Cis-element analysis of PpCKXs showed that all PpCKX genes have light-responsive elements and at least one hormone-responsive element.The changed relative expression levels of six PpCKX genes in peach buds from endodormancy to bud-break were observed by qRT-PCR.Among them,the expression trend of PpCKX6 was almost opposite that of PpEBB1,a positive bud-break regulator in woody plants,around the bud-break stage.Y1H,EMSA,and dual-luciferase assays indicated that PpEBB1negatively regulated PpCKX6 through direct binding to a GCC box-like element located in the promoter region of PpCKX6.In addition,a transient assay showed that overexpression of PpCKX6 delayed the bud-break of peach.These results indicate that the PpCKX genes play an essential role in the dormancy-regrowth process,and Pp CKX6may act downstream of PpEBB1 directly to regulate the bud-break process,which further improves the hormoneregulatory network of dormancy-regrowth of woody plants,and provides new insights for molecular breeding and genetic engineering of peach.

Effects of pre-oxidant(KMnO4)on structure and performance of PVDF and PES membranes

The structure and performance of membrane materials are very important to the efficient and stable operation in membrane drinking water purification technology. Potassium permanganate(KMnO_4), which can change the characteristics of organic matters and control membrane surface fouling, has been widely used as pre-oxidant in the front of membrane drinking water process. This study investigates the evolution of membrane surface structure and performance when polyvinylidene fluoride(PVDF) and polyethersulfone(PES) were exposed to10, 100 and 1000 mg·L^(-1) KMnO_4 solution for 6 and 12 d, respectively. The aged membrane physicochemical characteristics such as membrane surface morphology, chemical composition, hydrophilicity, porosity and zeta potential were evaluated by modern analytical and testing instruments. The anti-fouling property of membrane surface was also investigated by the filtration-backwash experiment. The results indicated that the different concentrations and exposure time of KMnO_4 led to a different variation on PVDF and PES membrane surface structure and performance, which could further affect the membrane separation performance and the membrane fouling behaviors. The membrane surface pore size and porosity increased due to the dislodgment and degradation of membrane additive(PVP), which improved membrane permeability and enhanced the adsorption and deposition of pollutants in the membrane pores. With the increase of exposure time, the membrane surface pore size and porosity reduced for the reactions of chain scission and crosslinking on membrane materials, and the backwashing efficiency declined, leading to a more serious irreversible fouling. Compared with PVDF membranes, the formation of sulfonic group for PES membranes increased the negative charge on membrane surface due to the oxidation of KMnO_4. The present study provides some new insights for the regulation of the pre-oxidant dose and the selection of the membrane materials in KMnO_4 pre-oxidation combined with membrane filtration system.

Effects of a novel bimetallic catalytic biofilter-based pretreatment technique on the form of ultrafiltration membrane fouling

Pretreatments of influents using bimetallic catalytic biofilter(BC-biofilter)can help reduce transmembrane pressures.For ultrafiltration membranes coupled with a conventional biofilter pretreatment,the cake layer resistance accounts for 25.0%of the total resistance.However,for those coupled with BC-biofilter pretreatment,the cake layer resistance accounts only for 12.5%of the total resistance.Confocal laser scanning microscopy is employed to determine the porosity of cake layer.It is found that ultrafiltration membranes with BC-biofilter pretreatment show a cake layer porosity of up to 0.56 or greater,whereas those with a conventional biofilter pretreatment exhibit a cake layer porosity of only 0.36.This is because micro-flocculation occurs in the effluents of BC-biofilter.The flocs generated through flocculation deposit on membrane surfaces to create highly porous cake layer.Moreover,catalytic reduction can increase the zeta potentials of the biofilter effluents.This makes the deposition of colloidal particles and flocs on membrane surfaces difficult under electrostatic repulsion.Simultaneously,micro-flocculation after BC-biofilter pretreatment can remove colloidal particles with particle sizes of200–350 nm in water.This can effectively prevent the blockage of ultrafiltration membrane pores.Furthermore,compared to conventional biofilter,BC-biofilter pretreatment can more effectively reduce the number of colloidal particles and the van der Waals forces of ultrafiltration membranes.They can also change the action directions of electric double layers and thereby mitigate ultrafiltration membrane fouling.

Syntheses and Co-Fluorescence of Complexes of Eu (III)/Gd (III) with Thienyltrifluoroacetonate, Terephthalic Acid and Phenanthroline

A series of complexes of europium (III)/gadolinium (III) with 2-thienyltrifluoroacetonate (HTTA), terephthalic acid (TPA) and phenanthroline (Phen) were synthesized by coprecipitation. The resulting complexes including Eu2(TPA)(TTA)4Phen2, Eu1.4Gd0.6(TPA)(TTA)4Phen2, Eu1.0Gd1.0(TPA)(TTA)4Phen2 and Eu0.8Gd1.2(TPA)(TTA)4Phen2 were characterized by elemental analysis, IR spectroscopy and thermal stability analysis. The results of analysis indicate that the complexes obtained have similar binuclear structure with each other. The thermal stability analysis indicates that the complexes Eu2(TPA)(TTA)4Phen2and Eu1.0Gd1.0(TPA)(TTA)4Phen2 possess good thermal stability, which melt at ~241°C and decompose at ~370°C - 430°C corresponding to the formation of the complexes. The fluorescence spectra of Eu2(1-x)Gd2x(TPA)(TTA)4Phen2 (x = 0 - 1) complex powders and their doped silica gels were studied. The co-fluorescence effect of Gd3+ ions in complex powders is different from that of their doped silica gels. The optimum concentration of Gd3+ for complex powders and their doped silica gels is 0.5 and 0.3 (molar fraction), respectively. The co-fluorescence distinction of Gd3+ ions for complex powders and their doped silica gels is preferably interpreted from the proposed binuclear structure together with monomolecular compositions of the complexes for the first time. Both intermolecular energy transfer and intra molecular energy transfer in cross binuclear monomolecular EuGd(TPA)(TTA)4Phen2 are thought to be responsible for the co-fluorescence effect of the complex powders;yet only the latter is thought to be responsible for the co-fluorescence effect in silica gels, for the complex molecules in this case are isolated from each other.

“署脆红”桃配套栽培技术

“署脆红”桃果大,全红,硬溶质,耐贮,产量高。为了能更好的栽培“署脆红”桃,本文结合其主要特性,从建园地选择、种植方法、土肥水管理、树体管理、花果管理、病虫害防治、适时采收等方面阐述相关要点,为种植者提供参考。

Preparation of Mn-Ce oxide-loaded Al_(2)O_(3)by citric acid-assisted impregnation for enhanced catalytic ozonation degradation of dye wastewater

The performance of supported catalysts is significantly affected by the dispersion degree of the active components on the support.In this study,citric acid(CA)was used as a modifier to prepare Al_(2)O_(3)supported Mn-Ce oxides(Mn-Ce/CA-Al_(2)O_(3))by the impregnation-calcination method.The characterization results showed that adding citric acid enhanced the dispersion of Mn-Ce oxides on the support,rendering Mn-Ce/CA-Al_(2)O_(3)with a larger specific surface area and abundant surface hydroxyl groups,thereby providing more reaction sites for catalytic ozonation.The Mn-Ce/CA-Al_(2)O_(3)exhibited excellent catalytic ozonation performance in degrading Reactive Black 5(RB5)dye.It achieved nearly complete decolorization of RB5 within 60 min,with a COD removal efficiency of 60%,which was superior to the sole ozonation(30%).Furthermore,the Mn-Ce/CA-Al_(2)O_(3)system demonstrated significant degradation of RB5 over a wide pH range of 3e11.Based on the XPS and EPR analysis results,a preliminary mechanism of catalytic ozonation over the Mn-Ce/CA-Al_(2)O_(3)was proposed.The redox cycle of Mn^(3+)/Mn^(4+)and Ce^(3+)/Ce^(4+)effectively accelerated the electron transfer process,thus promoting the generation of reactive oxygen species(ROS)and improving the degradation of RB5.Meanwhile,the Mn-Ce/CA-Al_(2)O_(3)exhibited superior catalytic stability and effective treatment capabilities for real dye wastewater.

补充蓝光对设施栽培油桃光合性能及糖酸积累的影响

以设施曙光油桃(Prunus persica cv.‘Shuguang’)为试材,设置补充蓝光处理,测定了生育期内5个关键时期叶片的光合性能相关参数及果实的糖酸组分,并观察了叶片气孔的变化情况。结果表明:补充蓝光后油桃叶片的净光合速率提高,叶绿素a和b含量增加,叶绿素a/b显著降低,叶面积增大;气孔开放提前并较早达到最大开度,且关闭延迟。叶片中检测到的主要同化物为果糖、葡萄糖和山梨醇,以山梨醇为主;果实中则为果糖、葡萄糖、山梨醇和蔗糖,成熟期以蔗糖为主。补充蓝光处理的叶片中3种同化物积累较少,而果实中总糖和蔗糖含量较高,表明蓝光处理提高了光合同化物从叶片到果实的转运转化能力。草酸是叶片和果实中主要的有机酸,补充蓝光处理的果实中有机酸含量显著降低,糖酸与对照相比提高了30.5%。硬核期后是蓝光处理提高果实糖酸比的关键时期,此时补充蓝光可改善设施油桃光合性能及果实品质,这一技术措施有望应用到设施果树的栽培中。

桃ERF转录因子家族生物信息学分析及芽萌发相关基因筛选

以中油四号油桃(Prunus persica var.nectarina)为研究对象,利用MEGA 6.0、MEME、GSDS和DNAMAN 6.0等软件对桃ERF家族数据进行生物信息学分析,鉴定得到102个ERF转录因子家族基因,并通过构建系统进化树将这102个基因分为10个子家族(I–X)。基因结构分析表明,有81个基因不含内含子,20个基因含有1个内含子,有1个基因与其它成员差异较大,含有5个内含子。保守元件分析表明,ERF家族包含20个保守元件,其中Motif 1、Motif 2和Motif 4都属于AP2/ERF结构域,同一个保守元件主要出现在同一个子家族中,并且大部分保守元件的功能未知。VIII子家族基因的荧光定量PCR分析表明,在桃叶芽处于不同的发育状态时,Ppe ERF068的表达量存在较大差异,光照培养箱中培养的桃芽在萌发过程中各时期表达量变化趋势进一步表明该基因可能与叶芽萌发有关,将其命名为Ppe EBB1。该研究为进一步揭示Ppe EBB1的分子机制奠定了基础,并为桃树的栽培管理和熟期调控了提供理论指导。

UV-B对设施桃叶片光合功能及叶绿体超微结构的影响

对温室栽培的油桃中油5号(Prunus persica var. nectarina cv.‘Zhongyou5’)适量补充UV-B,分析其对桃叶片光合功能及叶绿体超微结构的影响。结果表明,UV-B处理下各色素含量均有不同程度的增加,其中叶绿素b的含量和净光合速率(P)提升幅度较大。相较于未补充UV-B的桃树(对照), UV-B处理的F/F无显著变化, F’/F’比值、光化学猝灭系数(qP)、非光化学猝灭系数(qN)以及PSII实际光化学量子效率(Φ)均有显著或极显著升高。透射电镜结果显示,UV-B处理下叶绿体基质片层空隙小,堆叠紧密,叶绿体外膜边缘清晰。可见,温室内适量补充UV-B可快速改善叶片叶绿体的超微结构,提升叶绿素分子捕获光能及向PSII传递的能力,增大PSII反应中心的开放程度,提高实际光能转化效率和PSII电子传递量子效率,提高叶片的光合功能。该研究为设施果树光合性能改善和UV-B合理利用提供了理论依据。

The NAC transcription factor MdNAC4 positively regulates nitrogen deficiency‑induced leaf senescence by enhancing ABA biosynthesis in apple

Although it is well established that nitrogen(N)deficiency induces leaf senescence,the molecular mechanism of N deficiency-induced leaf senescence remains largely unknown.Here,we show that an abscisic acid(ABA)-responsive NAC transcription factor(TF)is involved in N deficiency-induced leaf senescence.The overexpression of MdNAC4 led to increased ABA levels in apple calli by directly activating the transcription of the ABA biosynthesis gene MdNCED2.In addition,MdNAC4 overexpression promoted N deficiency-induced leaf senescence.Further investigation showed that MdNAC4 directly bound the promoter of the senescence-associated gene(SAG)MdSAG39 and upregulated its expression.Interestingly,the function of MdNAC4 in promoting N deficiency-induced leaf senescence was enhanced in the presence of ABA.Furthermore,we identified an interaction between the ABA receptor protein MdPYL4 and the MdNAC4 protein.Moreover,MdPYL4 showed a function similar to that of MdNAC4 in ABA-mediated N deficiencyinduced leaf senescence.These findings suggest that ABA plays a central role in N deficiency-induced leaf senescence and that MdPYL4 interacts with MdNAC4 to enhance the response of the latter to N deficiency,thus promoting N deficiency-induced leaf senescence.In conclusion,our results provide new insight into how MdNAC4 regulates N deficiency-induced leaf senescence.