BackgroundWith the rising proportion of saline soils in the global irrigated soil area, improving salt stress tolerance in peach is of great significance and value for the development of peach industry. Plant U-box proteins (PUBs) are widely involved in various stress response processes. In this study, genome-wide identification and analysis of PUBs genes in cultivated peach were carried out, and the expression profiles of peach PUB genes in different tissues of peach as well as their responses under salt stress were also investigated.MethodsThe genome-wide identification of PUBs genes in cultivated peach was analysed by gene localisation, gene structure and evolutionary analysis. Subsequently, the expression profiles of PpPUB genes in different tissues of peach and the changes in the relative expression of peach PUB genes under ABA, GA3, IAA, 6-BA treatments, low-temperature stress and salt stress were investigated.Results and discussionIn this study, 51 U-box protein genes (PUB) were identified in the cultivated peach “SJZX” and divided into six groups. Most of the PpPUB were predicted to be located in the nucleus and chloroplasts. Promoter analyses indicated that most members may be associated with lightresponsive processes. Expression analysis based on RT-qPCR showed that most PUB members in peach were highly expressed in a certain tissues or organs. Based on the results of RT-qPCR expression analysis of 18 representative PpPUB after abiotic stress and hormone induction, all detected genes except for PpPUB19 were induced by salt stress, and PpPUB3/20/23/49 were induced by low temperature. Multiple genes were induced or repressed by exogenous hormone treatments. Furthermore, Arabidopsis seedlings heterologously overexpressing PpPUB20 exhibited greater salt tolerance than wild-type seedlings under the same salt stress conditions. These findings provide comprehensive information on the PpPUB family and identify PpPUB members that may be involved in the regulation of hormones and salt stress. Therefore, this study enhances the understanding of potential role of PpPUB in stress adaptation in peach, thereby establishing a foundation for subsequent functional investigations and applications in stress-resistant crop breeding.

Background: Low temperature pose significant challenges to peach cultivation, causing severe damage to peach buds and restricting production and distribution. Ethylene, an important phytohormone, plays a critical role in enhancing plant cold resistance. Structural genes and transcription factors involved in ethylene biosynthesis and signal transduction pathways are associated with cold resistance. However, no research has specifically addressed their roles in peach cold resistance.Methods: In this study, we aimed for cold-resistance gene discovery in cold-sensitive peach cultivar “21Shiji” (21SJ) and cold-resistance cultivar “Shijizhixing” (SJZX) using RNA-seq and gas chromatography.Results: The findings revealed that under cold stress conditions, ethylene biosynthesis in “SJZX” was significantly induced. Subsequently, a structural gene, PpACO1-1, involved in ethylene biosynthesis in peach buds was significantly upregulated and showed a higher correlation with ethylene release rate. To identify potential transcription factors associated with PpACO1-1 expression and ethylene signal transduction, weighted gene co-expression network analysis was conducted using RNA-seq data. Four transcription factors: PpERF2, PpNAC078, PpWRKY65 and PpbHLH112, were identified.Conclusion: These findings provide valuable theoretical insights for investigating the regulatory mechanisms of peach cold resistance and guiding breeding strategies.

为了确定"石门核桃"种质资源的遗传多样性,采用SSR标记技术,对20份"石门核桃"实生优株,15份核桃种质资源进行了遗传多样性分析.结果表明,筛选出的16对SSR引物扩增的等位基因变幅为3～10,片段范围100～306 bp,多态性信息含量在0.481 0～0.765 6之间,具有较高的多态性.采用UPGMA法在遗传距离0.26处将35份资源分为5类,麻核桃种质盘龙纹独自聚为1类,"石门核桃"实生资源与其他种质资源分布于其他4类中.

果园生草是较为科学的现代果园土壤管理技术,于19世纪末在美国出现[1],在欧美、日本等农业发达国家,生草果园已占果园总面积的60％以上,在有的国家甚至超过了 90％[2].果园生草具有很多优点:1)减少土壤和水分流失;2)增加土壤有机质含量,并提高土壤养分和碳源利用率[3-4];3)改善土壤理化性质,增加团粒结构[5-6];4)增加天敌数量和丰富度,提高果园生物多样性[7];5)调节果园小气候,增加空气湿度,调控土壤温度,春季提高土壤温度、夏季降低土壤温度[8];提高果实产量和可溶性固形物含量,减少日灼,提高果实品质[9-10];6)便于果园推行机械作业,提高劳动效率;7)生草果园可以养殖畜禽,提高经济效益;8)行间种植开花植物可以增加果园的观光价值,促进旅游业发展.

低温霜冻影响着茄子的栽培范围和栽培时间,因此筛选和培育耐低温的茄子品种和资源,是茄子生产和科研面临的紧要任务.茄子在遭受低温胁迫时,会导致外部形态和内部生理生化发生变化.低温胁迫对叶片的影响最为直观,如叶片出现萎蔫、下垂、有水渍斑等现象.根据茄子在低温胁迫下的形态变化,计算低温伤害指数并进行低温伤害分级,可以清楚的显示其受到低温伤害的程度[1].当温度低于茄子承受的临界值时,其茄子组织细胞膜的透性增大,细胞内电解质的外渗程度也会增加.

The carotenoid composition and content in the yellow sarcocarp peach are a direct indicator of quality. Therefore, discoveries regarding the identification of candidate genes related to carotenoid accumulation and their regulatory mechanisms would be beneficial for yellow sarcocarp peach breeding. In this study, the white sarcocarp peach cultivar '21shiji' (21SJ) and its unique yellow sarcocarp bud mutation individual (21BM) were used for carotenoid determination and candidate gene discovery based on UPLC-APCI-MS/MS and RNA-seq. In total, 11 carotenoid compositions showed significant differences between '21SJ' and '21BM', including four carotenes and seven xanthophylls. Furthermore, the accumulation of β-carotene, zeaxanthin, β-cryptoxanthin, antheraxanthin, violaxanthin, and capsanthin showed different tendencies between '21SJ' and '21BM' during the ripening stage and influenced '21BM' yellow sarcocarp formation. Using transcriptome analysis, we found that the differential expression of candidate genes PpZEP, PpVDE1, PpCCD4, and PpCCS were major influencing factors. Two transfactors, PpbHLH14 and PpMYB73, were significantly related to PpZEP, PpVDE1, PpCCD4, and PpCCS expression and carotenoid accumulation after weighted gene co-expression network analysis. The identified structural genes and transcription factors in this study will further enrich carotenoid accumulation regulatory mechanism in peach and will provide an important theoretical reference for yellow sarcocarp peach breeding.

Titanium oxo clusters (TOCs) with accurate molecular structures have potential applications in photocatalysis, such as photocatalytic degradation, hydrogen production, and water oxidation. The hydrolytic stability and light absorption ability of TOCs have important impacts on photocatalysis, where the selection of peripheral organic ligands plays a significant role. In this regard, salicylhydroxamic acid (abbreviated as H3L) attracts our attention, acting as a ligand for its multidentate and dye-functional features, which can increase the hydrolytic stability and broaden light absorption for TOCs. Herein, two TOCs were solvothermally synthesized and structurally characterized using H3L, formulated as [Ti8(μ2-O)2(μ3-O)2(OiPr)12(L)4]·2CH3CN (1) and [Ti16(μ2-O)10(μ3-O)4(PhCOO)14(L)6(HL)2]·4CH3CN·2iPrOH (2). Complex 2 was obtained by adding excessive benzoic acid over the reaction system of 1, resulting in enhanced hydrolytic stability via the replacement of all alkoxy ligands by multidentate ligands for protection. Interestingly, for the first time, the "three-in-one" structural building mode with {Ti6} + {Ti4} + {Ti6} by the common subunits in 2 was observed among all reported TOCs. Moreover, complex 2 can strongly absorb visible light reaching up to 700 nm and exhibit obvious activity for the photodegradation of methyl orange.

Objectives Peach (Prunus persica L.) is an ancient fruit tree that originated from China. It is the climacteric fruit belonging to genus Prunus in family Rosaceae. Ethylene, which is produced during ripening, accelerates fruit softening, and therefore peaches cannot be stored for a long time.Materials and Methods To study the mechanism of fruit late ripening, transcriptome analysis of the fruit of a late-ripening mutant of 'Jinghong' peach was performed to identify genes and pathways involved in fruit late ripening.Results A total of 1805, 1511, and 2309 genes were found to be differentially expressed in W2_vs_M1, W3_vs_M2, and W3_vs_M3, respectively. Functional enrichment analysis of the differentially expressed genes showed they were related to carotenoid biosynthesis, starch and sucrose metabolism plant hormone signal transduction, flavonoid biosynthesis, and photosynthesis. The expression trends of ripening-related genes that encode transcription factors and plant hormone signal transduction-related genes that encode enzymes were similar.Conclusions It will help to elucidate the transcriptional regulatory network of fruit development in the spontaneous late-ripening mutant of 'Jinghong' peach and provide a theoretical basis for understanding the molecular regulatory mechanism of fruit ripening.

'早硕'为新疆核桃与卢龙当地"石门核桃"的自然杂交后代,由河北省林业科学研究院在秦皇岛卢龙实生树中选出.'早硕'丰产性好,成龄树平均结果枝率64.3％,侧芽结果率82.2％,667 m2产量达350 kg干果,具有较强的抗病能力和抗冻能力.'早硕'果实大,单果质量16.65 g,壳薄,内褶壁退化,横隔膜膜质,易取整仁,出仁率56.5％.'早硕'核桃果大、壳薄、易出整仁,鲜食香甜可口,深受广大消费者欢迎[1].近两年,秦皇岛地区'早硕'青皮核桃收购价达4.2元/kg,很多果农纷纷将核桃老品种园和实生园进行改造,改接'早硕'品种.

大樱桃栽培和生产已成为秦皇岛市的重要农业产业之一.然而,大樱桃生产却面临着设施栽培少、产品质量不高、病虫害多发和自然灾害等诸多问题.为了更好地促进秦皇岛大樱桃产业的发展,针对秦皇岛大樱桃栽培和生产现状中存在的问题提出了相应的建议.

为了探究桃缝合线局部早熟的分子机制,该研究以'京红'桃芽变(JHM)及其野生型(JHW)的果实为试材,测定分析了缝合线和果面部位的硬度、花青素含量以及差异基因的表达特征.结果显示:(1)'京红'桃芽变比其野生型果实晚成熟约2周,芽变果实缝合线部位比果面部位局部早成熟,且提前2周时间转为红色.(2)随着果实的成熟,'京红'桃野生型及其芽变的果实硬度逐渐降低,花青素含量逐渐升高,并均在花后66 d发生明显变化,芽变缝合线部位硬度比果面部位更低,花青素含量比果面更高.(3)在花后66 d,芽变果实的缝合线与果面部位差异表达基因数高达1889个,显著富集在代谢途径、次生代谢产物的生物合成、植物激素信号转导、苯丙素的生物合成等代谢途径;从中筛选到24个缝合线早熟相关基因,包含5个细胞壁降解相关基因,9个色素合成、调控相关基因,5个乙烯合成与转导相关基因,3个生长素应答基因和2个NAC转录因子.(4)对24个早熟相关基因中的12个差异表达基因进行荧光定量验证结果表明,基因表达趋势与转录组测序结果相一致.研究发现,桃芽变果实种仁产生的乙烯通过缝合线向周围扩散,促进缝合线部位ACS1和ACO1等基因的转录,并合成了较多乙烯,乙烯又进一步调控该部位PG、XTH33、CHS、DFR等细胞壁降解与色素合成相关基因的表达,导致该部位的果肉提前成熟.

[目的]研究欧李果实发育过程中的挥发性成分与含量变化,揭示果实香气的香型转化特征,明确参与挥发物合成的主要代谢途径,为探讨果实香气代谢机制及品质育种提供数据支持.[方法]以'燕山1号'欧李为试材,采用顶空固相微萃取-气相色谱仪-质谱联用技术(HS-SPME-GC-MS),自坐果25 d开始,每隔10 d对果实挥发性成分进行测定.利用解卷积系统(AMDⅠS)与NⅠST11质谱库以及保留指数(RⅠ)对挥发性成分进行鉴定,内标法确定挥发物含量,进一步明确果实香气品质与香型转化特征以及不同挥发物类型合成的主要代谢途径.[结果]发育期内共检测到140种挥发物,幼果期明显多于其他时期,成分复杂;绿果期挥发物生成速率显著升高,含量增加.酯、萜类是主要挥发物类型,含量占90％以上.青香型挥发物在幼果期至着色期内含量丰富,商熟期内显著降低;果香型挥发物自商熟期逐渐增加,花香型挥发物在完熟期内显著增加.OAVs表明幼果期至绿熟期花香强度高,是主要香气特征,着色期开始果香强度随发育期逐渐增加,完熟期后果香与花香强度接近,是成熟果实的典型香气特征.幼果期挥发物代谢途径复杂,产生的挥发物类型丰富,其中参与萜类合成主要为MEP和MVP代谢途径,参与醛、醇、酯类合成主要为脂肪族和氨基酸代谢途径;绿熟期至商熟期萜类物质代谢程度与参与酯类合成的氨基酸代谢程度明显降低,不饱和脂肪酸代谢程度明显增加;完熟期不饱和脂肪酸代谢活跃度降低,参与酯类合成的饱和脂肪酸和氨基酸代谢途径以及参与单萜合成的脂肪酸β-氧化途径与脱辅基类胡萝卜素裂解途径增强,形成了大量支链酯类和芳香酯类以及环状单萜,对于典型成熟果实香气的形成具有重要作用.[结论]欧李果实发育过程挥发物变化明显,合成代谢途径具有明显更替.发育早期产生的挥发物有助于果实发育和环境适应;绿熟期以不饱和脂肪酸为底物的己酯、己烯酯类合成途径明显加强,挥发物逐渐积累;着色期果实快速生长,挥发物合成具有滞后性,代谢途径明显转化;完熟期参与支链酯、芳香酯、环状单萜的合成代谢途径明显增强,与成熟果实香气明显相关.典型果实香气主要形成于完熟期,稍晚于生理成熟期,适当延迟采收有助于果实芳香品质的形成与保留.

对秦皇岛市核桃产业发展现状进行了调研与分析,总结了核桃产业发展中存在的主要问题.基于核桃产业发展进程中存在的主要问题,提出了一系列建议,以期为加快秦皇岛市核桃产业发展提供指导.

[目的]以8份核桃资源为材料,分析核桃坚果的主要香气物质及其构成特点,明确品种间差异.[方法]采用顶空固相微萃取结合气质联用技术(HS-SPME/GC-MS)测定核桃核仁的香气成分.用3-辛醇进行标定,计算香气物质的含量,对检测结果进行分析.[结果]萃取温度70℃,萃取时间60 min是核桃香气成分萃取的最佳条件.定量分析8份核桃资源共检测到29种化合物,其中醛类物质11种,烷烃类物质4种,醇类物质3种,酯类物质3种,酚类物质1种,酸类物质4种,其他物质3种.8份核桃资源坚果的香气物质以醛类和烷烃类物质为主.不同核桃类型香气成分差异明显,石门核桃、'辽宁1号''香玲'以醛类物质为主,'清香'以烷烃类为主;香气浓郁的石门核桃中壬醛和(E,E)-2,4-十一烷二烯醛含量丰富.[结论]研究优化并建立了核桃香气成分测定方法,成功测定了8份核桃资源的香气成分构成,为核桃香气相关研究提供参考.

从实验室已测得的桃突变体缝合线易软的北京2号转录组数据中获得1个与果实软化相关的PME基因.以燕红桃果肉RNA为模板克隆出1条长度为1 113 bp的PME基因,命名为PpPME48(登录号:MT019687).生物信息学分析表明,PpPME48编码370个氨基酸,蛋白质分子量为41 187.06 ku,包含1个果胶甲酯酶结构域,具有1个较长的N端-PRO区域,属于TypeⅡ型.进化树分析表明,PpPME48蛋白与扁桃、乌梅和甜樱桃的PME蛋白亲缘关系较近.荧光定量PCR结果显示,PpPME48基因在缝合线易软品种燕红中的表达高于不易软化品种晚久保,而且在缝合线处的表达量明显高于果面处.因此,PpPME48基因是一个与缝合线变软密切相关基因.

以秦皇岛地区的31份桃资源为试材,在早、中、晚熟桃中筛选出3份缝合线易软资源'Z1-2'"超越2号""绿化久";"曙光"'P2-1'"晚久保"3份缝合线不易软资源作为对照.探究影响缝合线软化的相关因素对这些品种的缝合线和果面部位的果实硬度、可溶性固形物、花青素含量、乙烯峰度和脱落酸(ABA)含量进行测定,研究了桃果实缝合线处提前软化对果实品质的影响,以期丰富桃果实缝合线软化的生理基础.结果表明:在易软品种中,缝合线处的乙烯峰度和花青素含量显著高于果面部位,而缝合线处硬度显著低于果面;在对照品种中,乙烯峰度、花青素含量与硬度在缝合线和果面部位的差异均不显著.在6个品种中,缝合线处的可溶性固形物含量均低于果面,ABA变化无规律,与缝合线软化没有相关性.

以秦皇岛核桃实生资源为试材,分析了核桃坚果单果质量、出仁率、纵横径、果形指数、核壳厚度、核仁颜色、口感等品质指标,以期为石门核桃种质资源研究、创新和培育新品种奠定基础.结果 表明:在秦皇岛卢龙、抚宁、昌黎、青龙等地共搜集获得97个核桃实生单株,其单果质量12.15～24.11 g,核仁质量5.45～12.07 g,出仁率37.17％～61.57％,核壳厚度0.79～2.02mm,多为圆形或近圆形果.筛选出的10个优株具有大果、壳薄,易出整仁,核仁饱满、颜色浅,脂肪含量高,香而不涩等特点.该研究搜集获得的97个单株为石门核桃种质资源研究、创新提供了材料,其中10个优株是石门核桃新品种培育的基础.

The ripening of papaya is a physiological and metabolic process associated with accumulation of carotenoids, alternation of flesh color and flavor, which depending on genotype and external factors such as light and hormone. Transcription factors regulating carotenoid biosynthesis have not been analyzed during papaya fruit ripening. RNA-Seq experiments were implemented using different ripening stages of papaya fruit from two papaya varieties. Cis-elements in lycopene β-cyclase genes (CpCYC-B and CpLCY-B) were identified, and followed by genome-wide analysis to identify transcription factors binding to these cis-elements, resulting in the identification of CpbHLH1 and CpbHLH2, two bHLH genes. The expressions of CpbHLH1/2 were changed during fruit development, coupled with transcript increase of carotenoid biosynthesis-related genes including CpCYC-B, CpLCY-B, CpPDS2, CpZDS, CpLCY-E, and CpCHY-B. Yeast one-hybrid (Y1H) and transient expression assay revealed that CpbHLH1/2 could bind to the promoters of CpCYC-B and CpLCY-B, and regulate their transcriptions. In response to strong light, the results of elevated expression of carotenoid biosynthesis-related genes and the changed expression of CpbHLH1/2 indicated that CpbHLH1/2 were involved in light-mediated mechanisms of regulating critical genes in the carotenoid biosynthesis pathway. Collectively, our findings demonstrated several TF family members participating in the regulation of carotenoid genes and proved that CpbHLH1 and CpbHLH2 individually regulated the transcription of lycopene β-cyclase genes (CpCYC-B and CpLCY-B). This study yielded novel findings on regulatory mechanism of carotenoid biosynthesis during papaya fruit ripening.

花葶数量是衡量水仙(Narcissus tazetta var.chinensis)商品鳞茎品质的重要指标之一.传统的水仙鳞茎熏蒸方法由于不能严格控制乙烯浓度,导致花芽诱导效果不佳.本实验研发了乙烯处理水仙催多花技术,采用200 μL/L乙烯气体在密闭容器中熏蒸水仙三年生鳞茎两次,可使花葶和小花数量提高1倍.为探讨乙烯催多花的原因,测定了不同处理的生理生化指标,并将处理后1d的样品分别进行了转录组测序.外源乙烯增加了可溶性糖与蛋白质含量,提高了过氧化物酶(peroxidase,POD)活性、吲哚乙酸(indole-3-acetic acid,IAA)和玉米素(zeatin,ZA)水平.对水仙鳞茎转录组测序,共获得了65 898个unigenes,其中对照55 793个unigene、1-甲基环丙烯(1-methylcyclopropene,1-MCP)处理57 321个unigene、乙烯处理64 350个unigene.基因本体(Gene Ontology,GO)分析显示,外源乙烯处理提高了水仙鳞茎的活性,促进了GO term中大部分基因的上调表达.通过比较不同处理间基因的差异表达,筛选了62个候选基因,包含4个淀粉与蔗糖代谢途径基因、9个多胺合成与转运基因、11个木质素合成与转运基因、31个成花相关基因和7个其他调控基因.12个基因的qRT-PCR结果验证了RNA-Seq的正确性.这些差异表达基因在水仙花芽分化过程中可能具有重要作用.本研究在生理生化和分子水平对乙烯处理促进水仙鳞茎花芽分化机制进行了探讨,为进一步阐明水仙花芽分化分子机制和指导水仙提供了理论依据.