目的 探讨云香水仙WD40基因在花色形成中的作用.方法 基于前期的转录组数据,以云香水仙为材料,采用RT-PCR技术对WD40基因进行克隆,并结合Real-time PCR检测其在不同花期的表达水平.结果 克隆得到1个WD40基因,命名为NtWD40,开放阅读框长为1 020 bp,共编码339个氨基酸.同源性分析表明,云香水仙与拟南芥、苹果、矮牵牛及苜蓿的相似系数分别为68%、68%、68%和69%.Real-time PCR分析表明:始花期NtWD40的表达量较其他花期有明显差异.结论 NtWD40可能参与云香水仙类黄酮途径相关色素的合成.

The Chinese narcissus is a well-known monocotyledon plant with a beautiful color, and fresh with a sweet floral scent. Lack of transcriptomic and genomic information hinders understanding of the molecular mechanisms underlying the biosynthesis of narcissus floral scent volatiles. Here we predicted the functions of identified significantly differentially expressed genes (DEGs), according to public protein annotation databases. Using RNA-sequencing (RNA-Seq) on the Illumina HiSeq system and de novo transcriptome assembly, we investigated gene expression in narcissus corona and petal tissues at the early flowering (day 1) and full-bloom (day 7) stages. Significant differences in the expression profiles of 14 fragrance-related genes were further analyzed by qRT-PCR. A total of 62,826,860,514 bases were generated by RNA-seq; clean reads were 210,658,254 bp, and the guanine-cytosine content was 47.7%–48.88%. Transcripts (n = 167,374; 67.27%) and unigenes (n = 81,442; 32.73%) had mean lengths of 1069.70 bp and 813.27 bp, respectively. The total length and N50 length values of transcripts were 179,040,048 bp and 1654 bp, while those of unigenes were 66,234,291 bp and 1406 bp. Assembled genes were annotated by comparison with the non-redundant, Protein family, Clusters of Orthologous Groups of proteins, Swiss-Prot, Kyoto Encyclopedia of Genes and Genomes, and Gene Ontology, public protein databases. Additionally, 46 and 71 significantly differentially expressed genes encoded enzymes and transcription factors, respectively, associated with floral volatiles biosynthesis pathways, were analyzed in-depth. Our findings represent a fundamental step toward better understanding of the mechanisms of narcissus floral volatile biosynthesis.

采用常规压片方法,对5种国外引进的水仙体细胞染色体数目和核型进行了分析.结果表明:5种水仙材料中有二倍体1种,三倍体和四倍体各2种,核型公式分别为2n=4x=28=8m+16sm+4st（‘苏娅’）、2n=3x=30=7m+17sm+5st+1t（‘小燕子’）、2n=3x=21=4m+13sm+4st（‘普韦布洛’）、2n=4x=28=8m+15sm+4st+1t（‘胡德山’）和2n=2x=17=1m+9sm+7st（SAT）（‘温斯特丘吉尔’）.5种水仙染色体数目和核型分析结果不仅可以为其分类提供细胞学依据,同时也为利用这些品种资源选育新品种提供指导.

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.

以'云香'、'黄花2号'、白花Ⅰ号和白花Ⅱ号4种多花水仙为材料,测定盐胁迫(NaCl浓度分别为0、50、100、150、200和250 mmol·L-1)7 d后水仙叶片叶绿素含量、丙二醛(MDA)含量、过氧化物酶(POD)活性及叶绿素荧光参数的变化,研究多花水仙的耐盐性.结果表明,盐胁迫下,4种水仙叶片的叶绿素含量均有所下降,当NaCl浓度增大到100 mmol·L-1时,白花Ⅰ号和白花Ⅱ号的叶绿素含量比'云香'和'黄花2号'下降得更为显著.MDA含量随着盐浓度的增大而上升,白花Ⅰ号和白花Ⅱ号的MDA含量明显高于'云香'和'黄花2号'.POD活性随着盐浓度的增大整体有所上升,但'云香'的POD活性呈先上升后下降的趋势.盐胁迫下,4种水仙的最大荧光产量(Fm)、潜在光化学效率(Fv/Fo)、最大光化学效率(Fv/Fm)、有效光化学效率(Fv′/Fm′)和光化学猝灭系数(qP)下降,初始荧光产量(Fo)上升;随着盐浓度的增大,白花Ⅰ号和白花Ⅱ号各种叶绿素荧光参数的变化比'云香'和'黄花2号'更加显著.总之,随着盐浓度的增大,4种水仙叶片叶绿素荧光参数的变化幅度明显小于叶绿素含量、MDA含量和POD活性的变化,表明短期盐胁迫对4种水仙造成一定程度的损伤,但没有对光系统造成不可逆的破坏,说明水仙具备一定的抗盐性.

生长素反应因子(Auxin response factors,ARFs)在植物生长发育过程调节生长素响应基因表达中发挥着重要的作用.为了解多花水仙ARF家族,基于转录组数据,通过NR、NT、Swiss-Prot和PFAM 4个数据库、NCBI网站和在线软件SMART的注释筛选,利用ExPASy-ProtParam tool、SOPMA、Prot Comp、MEME、MAGA和Heml软件进行氨基酸理化性质、蛋白二级结构、亚细胞定位、保守基序、系统进化树和小鳞茎萌发不同时期的表达模式分析.共筛选得到21个ARF家族基因,生物信息学分析12个全长基因蛋白长度在193-1 096 aa之间,预测的分子量(Mr)为20.46-122.2,等电点为5.19-7.97,全部为不稳定的亲水蛋白,亚细胞定位预测均位于细胞核中.进化树和基序分析表明,21个NtARF蛋白分为3个大组,GlassⅢ进一步被分为3个亚组,分支相近的ARF转录因子具有相同或相近的基序.NtARF8、NtARF13、NtARF 15、NtARF17和NtARF21都展现较高的表达模式,可能是通过正向调节生长素的含量来促进小鳞茎的萌发.本研究表明,NtARF家族可能在多花水仙扦插繁殖过程中发挥着重要作用,结果可为将来深入研究多花水仙ARF基因家族的功能奠定基础.

本研究利用RT-PCR技术从'云香'水仙的根中克隆得到了NtNAC1基因,并通过qRT-PCR技术分析了该基因的时空表达模式以及在逆境和逆境相关激素处理下的表达变化,结合分析过表达该基因的转基因烟草植株的表现等解析了该基因的功能.结果显示:NtNAC1基因全长1083 bp,其ORF为918 bp,编码306个氨基酸,N端含有NAM保守结构域,聚分在SNAC1亚组,与香蕉MusaSNAC1、小麦TaNAC47亲缘关系较近.实时荧光定量分析显示,NtNAC1的表达水平随花器官花瓣和副冠的发育呈先上升后下降趋势,始花期达到峰值;NtNAC1在根和叶中高表达,受ABA、MeJA、SA、H2O2、NaCl、PEG诱导上调,推测该基因可能参与'云香'水仙花器官的形态建成及响应非生物胁迫.进一步构建表达载体转化烟草,获得9株转基因植株.在高盐和干旱胁迫处理下,转基因植株根系发达、长势更好、存活率高,表明水仙NtNAC1过表达能提高烟草对高盐、干旱的耐受性,在抗逆中起正向调控作用,可作为提高水仙抗性的优良遗传基因资源.

为选育水仙花新品种,本研究共选择15个多花水仙资源材料,于2017年秋季在漳州进行露地栽培,观测其植物学性状及生物学特性.结果表明:15个水仙资源间的叶长、叶宽、花葶长度、每花葶小花数、小花直径、副冠直径、副冠杯深以及花药长度等有明显差异.萌芽期为10月底至12月底,抽葶期为11月底至翌年1月底,花期从12月初持续到第二年2月底,盛花期延续81 d,开花持续天数27～35 d.根据花色可分为4大类型,第一类为两色花类型,含7个资源,即Chinese Sacred Lily、Erlicheer、Galilee、Sol、Winter Sun、金三角、云香;第二类为白色花类型,含3个资源,即Znbal、Ziva、崇明(白);第三类为黄色花类型,含3个资源,即Golden rain、Grand SD'or、彩旺;第四类为其他花色类型,仅绿状元1种.按花期可以分为早、中、晚3种类型.通过观察比较,明确了15个资源的植物学性状和生物学特性.

Red-fleshed papaya is a good material to study the different carotenoids accumulation mechanism in the peel and flesh. Although the peel and flesh of papaya closely integrated into one body, the flesh coloration changing from white to red, while the exocarp coloration changing from green to yellow. In this study, the major carotenoids accumulation and the expression patterns of key carotenoid biosynthesis pathway genes in the process of papaya fruit ripening were studied, and the carotenoid biosynthetic pathways in the yellow peel and red flesh of papaya were investigated. The carotenoid composition in papaya flesh and peel were different. The major carotenoids were lutein and β-carotene in the peel, while lycopene in the flesh. The accumulation of carotenoids, including lycopene, β-carotene, and β-cryptoxanthin were considered to cause the orange-red color of papaya cv. ‘Daqing No.10’ flesh. The color of peel changed from green to yellow because of the fast degradation of chlorophyll and the appearance of carotenoids such as lutein and β-carotene. Thirteen genes that encode enzymes in the carotenoid biosynthetic pathway were detected in papaya fruit transcriptome: two phytoene synthase (PSY1, PSY2), two phytoene desaturase (PDS1, PDS2), one ζ-carotene desaturase (ZDS), four lycopene cyclase (CYCB, LCYB1, LCYB2, LCYE), one β-carotene hydroxylase (CHYB), one carotene ε-monooxygenase (LUT1), one violaxanthin de-epoxidase (VDE), and one zeaxanthin epoxidase (ZEP). The results of RNA-Seq and RT-qPCR showed the expression of carotenoid biosynthetic pathway genes was consistent with the change of carotenoid content. Carotenoid biosynthetic pathways in the yellow peel and red flesh of papaya were analysed based on the major carotenoids accumulation and the expression patterns of key carotenoid biosynthesis pathway genes. There was only a β-branch of carotenoid biosynthesis in the flesh of papaya, while there were both α- and β-branch of carotenoid biosynthesis in papaya peel. In the process of papaya fruit ripening, the α-branch was inhibited and the β-branch was enhanced in the peel. The differential carotenoid accumulation and biosynthesis pathway genes expression in peel and flesh, lay a foundation for further study and provide further insights to control fruit color and improve fruit quality and appearance.

[目的]番木瓜是典型的呼吸跃变型果实,外源乙烯处理使番木瓜呼吸跃变提前,促进果实成熟.分离番木瓜果实成熟相关miRNA,为深入了解呼吸跃变型果实的成熟分子机制奠定基础.[方法]利用高通量测序技术对乙烯(ETH)、1-MCP和清水对照(CG)处理的番木瓜果实进行miRNA和转录组高通量测序,然后对测序获得数据进行生物信息学分析,进行miRNA鉴定和靶基因预测,并与转录组测序结果进行关联分析.[结果]乙烯、1-MCP和对照处理分别获得10 734 196、16 486 803和16 067 290条纯净序列,共鉴定出523个miRNA.其中,已知miRNA个数为1-MCP(303)、CG(214)和ETH(239),新miRNA个数为1-MCP(184)、CG(188)和ETH(114).与对照相比,在乙烯处理中上调和下调表达的miRNA分别是123和72条.靶基因预测共获得5 053个靶基因,KEGG功能富集分析显示它们参与了戊糖、葡萄糖醛酸转换、淀粉和蔗糖代谢、卟啉和叶绿素代谢、类胡萝卜素合成等代谢途径.筛选出的番木瓜果实成熟衰老相关候选miRNA,包含4个果实软化调控相关miRNA(miR167-y、miR4993-x、miR3946-x和miR5059-x)、3个果实颜色调控相关miRNA(miR4993-x、miR815-y和miR7810-x)、3个激素调控相关miRNA (miR4993-x、miR8004-x和miR9722-x)和4个转录因子调控相关miRNA(miR5641-y、miR9722-x、miR838-y和miR319-y).[结论]筛选的番木瓜果实成熟衰老相关miRNA为今后果实成熟衰老调控网络研究提供了可能的线索.

为深入挖掘中国水仙转录组中萜类合成相关基因,了解中国水仙萜类代谢途径和分子调控机制,该研究以'云香'水仙为材料,在其盛花期花瓣与副冠转录组测序的基础上,筛选已注释的萜类合成途径基因并利用NCBI blastn进行再注释,通过对部分候选基因的表达量与生物信息分析进一步筛选出代表基因,采用RT-PCR技术克隆了水仙异戊烯基焦磷酸异构酶基因NaIDI,并对其蛋白序列与特异性表达进行分析.结果表明:(1)Blast比对筛选得到52个与萜类合成上游途径相关的Unigenes,二次筛选获得11个显著差异表达的代表基因.(2)NaIDI基因开放阅读框(ORF)长度为858 bp,编码285个氨基酸,其氨基酸序列与'金盏银台'水仙相似度97.19％;亚细胞定位预测显示该基因定位在叶绿体;系统进化分析表明其与芦笋亲缘关系比较近.(3)实时荧光定量分析结果表明,N aID I基因在水仙开花的不同时期和不同组织器官中差异表达显著,且在盛花期时副冠中的表达量最高,与中国水仙挥发性萜类化合物在开花不同时期和不同组织器官中的表达规律一致,表明NaIDI在萜类代谢中发挥着一定作用.

该研究选用多花水仙新品种‘云香’为材料,采用RT-PCR技术克隆得到NtNAC2,其开放阅读框为936bp,编码311个氨基酸.生物信息学分析显示,NtNAC2在N端含有NAM保守结构域,与单子叶植物芦笋、番红花和石斛等具有较近的进化关系.实时荧光定量检测显示,花瓣和副冠中NtNAC2基因的表达量随花器官发育逐渐上升,衰败期达到峰值;在ABA、MeJA、SA、H2O2、50℃、NaCl和PEG胁迫处理下,水仙根和叶中NtNAC2基因的表达量上调,且表现出时空表达特异性.为进一步鉴定其功能,构建植物表达载体转化烟草,获得10株转基因烟草,经半定量RT-PCR检测NtNAC2在转基因植株中过表达.高盐和干旱胁迫处理后转基因植株根长为野生型的2～3倍,叶片失水率低于30％,存活率高于60％.研究表明,‘云香’水仙Nt NAC2的过量表达提高了转基因烟草的抗旱性和耐盐性,可作为水仙抗逆分子育种的重要候选基因.

Aimed to study the characteristics and functions of ACS gene,in the present study,we cloned a 1-aminocyclopropane-1-carboxylate synthetase gene named NtACS 1 (GeneBank KX082936 )based on the RNA-Seq database from the flower of Narcissus tazetta var.'Yunxiang'using RT-PCR method.The length of the open reading frame (ORF)of ACS is 552 bp,encoding 183 amino acids coupled with a molec-ular weight of 20.6 kDa and theoretical isoelectric point of 6.30.qRT-PCR analysis showed that the rela-tive expression level of NtACS 1 both in petals and coronas are decreased gradually along with the aging of flower.Moreover,the expression data of NtACS 1 gene were consistent with those obtained by RNA-Seq, implied that the NtACS1 protein as an ACC synthetase might play a role in the catalytic system 1 of ethyl-ene biosynthesis.Furthermore,sense plant expression vectors of NtACS 1 were successfully constructed with agrobacterium mediated transformation,and 6 positive transgenic tobacco plants were ultimately ob-tained.Our current study will lay an experimental foundation for the future application of the genetic transformation to prolong florescence of 'Yunxiang'.

In this research,a gene named NtACOY2 encoding a novel ACC Oxidase (ACO) protein was isolated using RT-PCR from 'Yunxiang' (Narcissus tazetta var.'Yunxiang').The full length cDNA of NtACOY2 consisted of an open reading frame (ORF) of 936 bp,and encoded a 35.83 kD protein with 311 amino acids.Bioinformatics analysis indicated that NtACOY2 contained a typical DIOX_N and 20G-Fe Ⅱ_ Oxy binding domain.Evolutionary analysis indicated that the amino acid sequence encoded by NtACOY2 was highly conserved.Real-time fluorescence quantitativePCR results revealed that the expression of NtA-COY2 in the petal and deputy crown is increasing with the senescence of 'Yunxiang'.The expression of NtACOY2 in petals in each period was higher than that in the deputy crown,and the highest expression in petals is at bud stage.So it is inferred that NtACOY2 may be involved in the development of 'Yunxiang' and related to flower senescence.The expression vector of NtACOY2 was successfully constructed by PCR and identified by restriction enzyme digestion reactions.And the sense plant express vector of NtACOY2 was used to transform the tobacco through Agrobacterium-mediated procedure.PCR detection showed that a total of 15 transformed plants were amplified fragments with the same size as the positive controls.The result of RT-PCR identification showed that 12 transgenic tobacco plants were obtained.Two randomly selected transgenic plants (Z1,Z2) and wild type (WT) exactly the same condition of transplanting under greenhouse cultivation,the results showed that the flowering time of Z1,Z2 were 8 d and 7 d earlier flow-ering compared with control plants,and the flower number of transgenic tobacco were more than the wild type,it is showed that NtACOY2 could normally expressed at the transcriptional level.The experimental results laid the foundation for further research on the function of NtACOY2 gene.

WRKY transcription factors play an important adjusting role in the process of plant growth and development, hormone signal transduction and abiotic stress response.To clarify the gene Narcissus tazetea var.'Yunxiang', we cloned the NtWRKYY1 gene (GenBank accession No.KX056495) based on 'Yunxiang', analyzed the gene sequence features, evolutionary relationship and expression characteristics, constructed the expression vector before transformed into tobacco.Sequence analysis revealed that the length of NtWRKYY1 gene open reading frame (ORF) is 510 bp, encoding a polypeptide of 169 amino acids.Multiple alignments and phylogenetic analysis showed that NtWRKYY1 protein containing one WRKY consecutive structural domain and C2H2 type zinc finger(Cx4Cx23HxH)belong to Ⅱc sub-group of WRKY transcription factor together with Arabidopsis AtWRKY57.Tissue-specific expression and temporal and spatial expression showed that NtWRKYY1 in 'Yunxiang' had a much higher expression in flowers than that in roots and leaves, and a rising express trend in petal and corona of alabastrum stage, early flowering stage, full bloom stage and faded stage.NtWRKYY1 can be induced by abscisic acid (ABA), high temperature, drought and saline, and restrained by methyl jasmonate (JA) through hormones and abiotic stresses analyzing.We can concluded that NtWRKYY1 gene may play a regulating role during the flower senescence process in 'Yunxiang', involve in the hormone signal transduction of ABA, JA and the abiotic stress regulation of high temperature, drought and saline at the same time.In addition, we constructed overexpressing vector pMDC140-NtWRKYY1 using In-Fusion cloning technique, transformed into tobacco by the method of Agrobacterium though leaf disc transformation.The carrier of PCR and GUS staining results indicated the resistant plantlets were positive.This study will make a good foundation for further exploring the function of the WRKY transcription factor in 'Yunxiang'.

The WRKY transcription factors family gene NtWRKYY2(GenBank: KX056496)were cloned by PCR technology from Narcissus tazetta var.'Yunxiang'.The Open Reading Frame (ORF) of NtWRKYY2 contained 867 bp,encoding a protein of 289 amino acid residues.Multiple alignments and phylogenetic analysis showed that NtWRKYY2 proteins containing one WRKY consecutive structural domain and C2H2 type zinc finger(Csx4Cx23HxH)belong to Ⅱd sub-group of WRKY transcription factor together.Quantitative real-time PCR (qRT-PCR) analysis demonstrated that the NtWRKYY2 gene was obviously induced by salt stress in 'Yunxiang'.We constructed overexpressing vector pMDC140-NtWRKYY2 using In-Fusion cloning technique,and transformed into tobacco by the method of Agrobacterium though leaf disc transformation.The carrier of PCR results indicated that the resistant plantlets were positive and the converting rate of 72%.Salt stress and chlorophyll fluorescence parameter analysis showed that after the salt stress treatment,overexpression of NtWRKYY2 transgenic tobacco showed less wilt and chlorosis than the wild type plants,and the decrease of Fv/Fm value was less than the wild type plants.Studies have shown that overexpression of the NtWRKYY2 gene remarkably increased the salt tolerance in transgenic tobacco.This study offers an alternative gene for salt tolerant transgenic breeding of Narcissus.

Background Since papaya is a typical climacteric fruit, exogenous ethylene (ETH) applications can induce premature and quicker ripening, while 1-methylcyclopropene (1-MCP) slows down the ripening processes. Differential gene expression in ETH or 1-MCP-treated papaya fruits accounts for the ripening processes. To isolate the key ripening-related genes and better understand fruit ripening mechanisms, transcriptomes of ETH or 1-MCP-treated, and non-treated (Control Group, CG) papaya fruits were sequenced using Illumina Hiseq2500. Results A total of 18,648 (1-MCP), 19,093 (CG), and 15,321 (ETH) genes were detected, with the genes detected in the ETH-treatment being the least. This suggests that ETH may inhibit the expression of some genes. Based on the differential gene expression (DGE) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, 53 fruit ripening-related genes were selected: 20 cell wall-related genes, 18 chlorophyll and carotenoid metabolism-related genes, four proteinases and their inhibitors, six plant hormone signal transduction pathway genes, four transcription factors, and one senescence-associated gene. Reverse transcription quantitative PCR (RT-qPCR) analyses confirmed the results of RNA-seq and verified that the expression pattern of six genes is consistent with the fruit senescence process. Based on the expression profiling of genes in carbohydrate metabolic process, chlorophyll metabolism pathway, and carotenoid metabolism pathway, the mechanism of pulp softening and coloration of papaya was deduced and discussed. We illustrate that papaya fruit softening is a complex process with significant cell wall hydrolases, such as pectinases, cellulases, and hemicellulases involved in the process. Exogenous ethylene accelerates the coloration of papaya changing from green to yellow. This is likely due to the inhibition of chlorophyll biosynthesis and the α-branch of carotenoid metabolism. Chy-b may play an important role in the yellow color of papaya fruit. Conclusions Comparing the differential gene expression in ETH/1-MCP-treated papaya using RNA-seq is a sound approach to isolate ripening-related genes. The results of this study can improve our understanding of papaya fruit ripening molecular mechanism and reveal candidate fruit ripening-related genes for further research.

ACC oxidase (ACO) is a key enzyme in the biosynthesis pathway of ethylene.In order to explore the characteristics and function of the ACO gene in narcissus,the following work has been done in this study.Petals of Narcissus tazetta var.'Yunxiang'were used as experimental materials,a full-length 1 162 bp sequence was obtained by RT-PCR and named as NtACO1 (GenBank KX082935).The open reading frame (ORF) length of NtACO1 is 939 bp,which encodes 312 amino acids.Amino acid domain analysis showed that this gene has DIOX_N and 20G-Fe Ⅱ_Oxy domains and was identified as a member of the ACO protein family.Molecular phylogenetic tree analysis showed that ACO gene of'Yunxiang'was closely related to that of Narcissus tazetta var.chinensis,qRT-PCR results showed that the expression of NtACO1 increased gradually with Narcissus flower development and senescence,and the expression level in the petals were higher than that in contemporaneous coronas,indicating that the NtACO1 gene may be involved in the flower development and senescence of'Yunxiang'We obtained several NtACO1 overexpression transgenic tobacco plants using the Agrobacterium mediated.Compared with wild type,the vegetative growth stage of transgenic tobaccos was reduced,as well as the transgenic tobaccos showed early flowering and less leaves.This study lays an experimental foundation for further research on the function of ACO gene and provide a theoretical basis for the molecular breeding in prolonging plant florescence of Narcissus.

A sequence of one NA C gene from ‘Yunxiang’ transcriptome library was cloned using PCR technology.Sequence analysis indicates that the eDNA of NAC,named NtNAC3153 (GenBank accession number:KU375569),contained an open reading frame of length 822 bp (encoding 273 amino acids,molecular weight:30.903 9 ku).Physiochemical properties analysis and multiple sequence alignment showed that NtNAC3153 protein was a hydrophilic protein which was free of trans-membrane region and had a conserved N-terminal domain.Phylogenetic analysis indicated that the NtNAC3153 had the closest relationship with Musa acuminata MaNAC,Brachypodium distachyon BdNAC and Setaria italica SiNAC.Real-time PCR analysis showed that the expression of NtNA C3153 gene could be induced by ABA,salt stress and high temperatures.NtNA C3153 may be involved in the regulation of resistance mechanisms of ‘Yunxiang’.

为探究番木瓜NAC转录因子的序列特征及功能,以‘大庆7号’番木瓜果肉为试验材料,采用RT-PCR克隆出2个不同的NAC类基因,命名为CpNAC1(GeneBank KT364871)和CpNAC2(GeneBank KT372241),其开放阅读框(ORF)长度分别为609 bp和805 bp,分别编码202个和268个氨基酸,其N端含有NAM保守结构域.采用实时荧光定量PCR研究其在乙烯利及清水对照处理后果实不同成熟时期中的表达情况,结果发现,CpNAC1和CpNAC2基因随着处理后时间的增加,表达量呈先下降后缓慢上升的趋势,且均与果实成熟呈负相关.但CpNA C1表达趋势与果实成熟过程中乙烯的表达量相反,受乙烯抑制降低表达量,从而参与了番木瓜果实的成熟衰老进程,而CpNAC2基因在乙烯处理后番木瓜果实中表达量与对照处理相比没有显著变化,说明CpNAC2基因不是通过乙烯信号传导途径来调控果实成熟.