可食用香料产品质量一致性评价能够保证食品风味一致性。本文基于傅里叶变换离子回旋共振质谱(Fourier Transform Ion Cyclotron Resonance Mass Spectrometry,FT-ICR-MS)结合不添加内标物的手动进样策略建立了一种快速分析香料质量的方...可食用香料产品质量一致性评价能够保证食品风味一致性。本文基于傅里叶变换离子回旋共振质谱(Fourier Transform Ion Cyclotron Resonance Mass Spectrometry,FT-ICR-MS)结合不添加内标物的手动进样策略建立了一种快速分析香料质量的方法,采用降噪、插值与归一化预处理质谱数据,相关系数法筛选样品重复测试中的异常值,主成分分析法评价插值后数据的质量,以验证压缩数据是否具有可行性。结果表明,正离子模式下香料A和香料B的未稀释样品分别被划分到甲醇体积分数0%~2%与0%~3%范围内,实际生产中可将此范围内的样品认定为质量合格。负离子模式样品响应低,优先考虑正离子模式评价可食用香料。展开更多
Unlike annual flowering plants that exhibit a single reproductive cycle encompassing vegetative growth,flowering,and senescence within a single year,perennial woody trees undergo a transition between vegetative and re...Unlike annual flowering plants that exhibit a single reproductive cycle encompassing vegetative growth,flowering,and senescence within a single year,perennial woody trees undergo a transition between vegetative and reproductive growth every year after a long juvenile phase.Most woody fruit trees bloom when it turns warm in spring,and the fruit ripens in summer or autumn.However,as a member of the Maloideae subfamily,the loquat tree blooms in the cold autumn and winter,and the fruit matures in the spring.To explore the regulatory mechanism of loquat flowering,we characterized two FLOWERING LOCUS T homologous genes in loquat,EjFT1 and EjFT2.qRT-PCR results revealed that EjFT1 and EjFT2 exhibited nearly opposite expression patterns in various tissues.EjFT1 was mainly expressed in young tissues;EjFT2 was mainly expressed in mature leaves,open flowers,and fruits.EjFT2 exhibited an obvious circadian rhythm and was regulated by EjCO.After the trees were exposed to short-day conditions or sprayed with exogenous GA_(3),the expression of EjFT2 was strongly inhibited,and the loquat tree did not produce floral buds.Furthermore,the yeast two-hybrid,bimolecular fluorescence complementation,and Dualluciferase assay experiments revealed that both EjFT1 and EjFT2 interacted with EjFD,with the EjFT2-EjFD protein complex enhancing the activity of EjAP1-1 and EjAP1-2 promoters,while EjFT1-EjFD inhibited the activity of the EjAP1-1 promoter.Protein structural analysis of EjFT1and EjFT2 suggested that differences in amino acid residues at Val_(123)/Leu_(123),Ser_(157)/Ala_(157),and Val_(158)/Ala_(158)may be the reason for their functional differences.Our results showed that EjFT1 and EjFT2 may cooperatively regulate the floral bud differentiation of loquat by competitively binding with EjFD.EjFT2 regulates the onset of loquat floral bud differentiation by responding to photoperiod and gibberellin signals,while EjFT1 is involved in the vegetative growth of loquat.These findings provide important clues for the investigation of the regulatory mechanism of loquat flowering and advance the exploration into the multiple roles of FT homologous genes in regulating the reproductive transformation and vegetative growth of flowering plants.展开更多
文摘可食用香料产品质量一致性评价能够保证食品风味一致性。本文基于傅里叶变换离子回旋共振质谱(Fourier Transform Ion Cyclotron Resonance Mass Spectrometry,FT-ICR-MS)结合不添加内标物的手动进样策略建立了一种快速分析香料质量的方法,采用降噪、插值与归一化预处理质谱数据,相关系数法筛选样品重复测试中的异常值,主成分分析法评价插值后数据的质量,以验证压缩数据是否具有可行性。结果表明,正离子模式下香料A和香料B的未稀释样品分别被划分到甲醇体积分数0%~2%与0%~3%范围内,实际生产中可将此范围内的样品认定为质量合格。负离子模式样品响应低,优先考虑正离子模式评价可食用香料。
文摘金花茶组(Sect. Chrysanthae)植物具有很高的观赏价值,但其开花习性各不相同。为探究金花茶组植物成花机制,本研究以四季金花茶(Camellia perpetua)、金花茶(C. petelotii)和淡黄金花茶(C. flavida) 3种典型的金花茶为材料,克隆了控制成花转变的关键基因FLOWERING LOCUS T (FT)和CENTRORADIALIS1(CEN1)以及它们的启动子,对基因和启动子的结构特点进行分析,并通过RT-qPCR对三种金花茶不同组织中的FT和CEN1的表达进行定量分析。结果显示三种金花茶FT和CEN1编码的氨基酸序列极为相似,推测它们的功能可能相同。基因表达分析显示三种金花茶的FT基因主要在叶片中表达,在花芽、苞片中表达量较低,其中四季金花茶的CperFT基因在嫩叶及其叶柄和幼态叶的叶柄中表达量较高;三种金花茶CEN1主要在逐渐张开、显露色泽的花蕾中表达,且在花器官中表达量各不相同,在叶片、顶芽和花芽中的表达量相对较低。启动子序列分析显示,三种金花茶FT和CEN1启动子均具有不同数量的TATA-box和CAAT-box核心元件,同时激素响应、生物和非生物胁迫响应元件也存在差异。金花茶和四季金花茶的FT和CEN1启动子序列比较接近,淡黄金花茶CflaFT和CflaCEN1与它们相差较大。本研究结果表明三种金花茶开花习性的差异可能不是由FT和CEN1编码的蛋白功能差异引起的,很可能与它们的表达模式差异有关。
基金supported by the Guangdong Basic and Applied Basic Research Foundation(Grant No.2024A1515013095,2021A1515011048)the Open Fund of the Guangdong Provincial Key Laboratory of Utilization and Conservation of Food and Medicinal Resources in Northern Region(Grant No.SY-KFFMR2022009Z)Shaoguan City Science and Technology Planning Project(Social Development Direction-Supporting Scientific Research Workers Project)(Grant No.200811094530739)。
文摘Unlike annual flowering plants that exhibit a single reproductive cycle encompassing vegetative growth,flowering,and senescence within a single year,perennial woody trees undergo a transition between vegetative and reproductive growth every year after a long juvenile phase.Most woody fruit trees bloom when it turns warm in spring,and the fruit ripens in summer or autumn.However,as a member of the Maloideae subfamily,the loquat tree blooms in the cold autumn and winter,and the fruit matures in the spring.To explore the regulatory mechanism of loquat flowering,we characterized two FLOWERING LOCUS T homologous genes in loquat,EjFT1 and EjFT2.qRT-PCR results revealed that EjFT1 and EjFT2 exhibited nearly opposite expression patterns in various tissues.EjFT1 was mainly expressed in young tissues;EjFT2 was mainly expressed in mature leaves,open flowers,and fruits.EjFT2 exhibited an obvious circadian rhythm and was regulated by EjCO.After the trees were exposed to short-day conditions or sprayed with exogenous GA_(3),the expression of EjFT2 was strongly inhibited,and the loquat tree did not produce floral buds.Furthermore,the yeast two-hybrid,bimolecular fluorescence complementation,and Dualluciferase assay experiments revealed that both EjFT1 and EjFT2 interacted with EjFD,with the EjFT2-EjFD protein complex enhancing the activity of EjAP1-1 and EjAP1-2 promoters,while EjFT1-EjFD inhibited the activity of the EjAP1-1 promoter.Protein structural analysis of EjFT1and EjFT2 suggested that differences in amino acid residues at Val_(123)/Leu_(123),Ser_(157)/Ala_(157),and Val_(158)/Ala_(158)may be the reason for their functional differences.Our results showed that EjFT1 and EjFT2 may cooperatively regulate the floral bud differentiation of loquat by competitively binding with EjFD.EjFT2 regulates the onset of loquat floral bud differentiation by responding to photoperiod and gibberellin signals,while EjFT1 is involved in the vegetative growth of loquat.These findings provide important clues for the investigation of the regulatory mechanism of loquat flowering and advance the exploration into the multiple roles of FT homologous genes in regulating the reproductive transformation and vegetative growth of flowering plants.
