考虑当地流动特征的Zwart-Gerbera-Belamri空化模型改进及应用

为减小Zwart-Gerbera-Belamri空化模型中经验参数取值对数值模拟结果的影响,基于当地流动特征修正了Zwart-Gerbera-Belamri空化模型.联立Realizable k-ε湍流模型,分别采用修正前后的Zwart-Gerbera-Belamri空化模型对二维NACA0009 MOD水翼空化流场进行了数值模拟,空化数范围为0.75~0.90.并采用修正前后的Zwart-Gerbera-Belamri空化模型对二维Clark-Y水翼的初生空化、片状空化、云空化进行非定常数值模拟,空化数范围为3.00~0.55.将数值模拟结果与已有实验结果进行对比,结果表明:引入当地流动特征可以有效减小Zwart-Gerbera-Belamri空化模型中的气泡半径及气核体积分数的取值对数值模拟结果的影响,且修正后的空化模型能够捕捉不同空化数下绕Clark-Y翼型的时均升阻力系数的变化趋势.

大丁草(Gerbera anandria(L．)Sch Bip．)对腺嘌呤诱导的慢性肾功能衰竭大鼠TGF-β1和ET-1mRNA表达的影响

采用Wistar大鼠灌胃腺嘌呤4周复制慢性肾衰模型后用大丁草水煎液进行灌胃治疗,4周后检测各组肾功能、肾脏组织病理学改变及转化生长因子-β1(TGF-β1)和内皮素-1(ET-1)mRNA的表达结果发现大丁草组大鼠血肌酐和尿素氮浓度分别为(89.33±15.21)μmol/L和(21.52±3.95)mmol/L与治疗前的建模组(290.33±74.55)μmol/L和(32.30±2.35)mmol/L以及病理对照组(149.67±24.95)μmol/L和(33.18±2.95)mmol/L比较有所下降,经统计P<0.05,差异具有显著性与病理对照组相比大丁草组大鼠基因TGF-β1和ET-1表达也明显降低,与看家基因GAPDH的比值分别由(0.202 6±0.050 3)和(0.1949±0.0969)下降为(0.1285±0.0447)和(0.07810±0.0229),经统计P<0.05,差异具有显著性.由此认为大丁草对腺嘌呤所致慢性肾功能衰竭大鼠肾脏有保护作用,其机制可能是通过抑制TGF-β1和ET-1的表达来缓解肾脏损伤,恢复肾功能.

Effects of osmotic stress on antioxidant enzymes activities in leaf discs of P_(SAG12)-IPT modified gerbera

Leaf senescence is often caused by water deficit and the chimeric gene PSA612-1PT is an auto-regulated gene delaying leaf senescence. Using in vitro leaf discs culture system, the changes of contents of chlorophylls, carotenoids, soluble protein and thiobarbituric acid reactive substance （TBARS） and antioxidant enzymes activities were investigated during leaf senescence of PSA612-1PT modified gerbera induced by osmotic stress compared with the control plant （wild type）. Leaf discs were incubated in 20%, 40% （w/v） polyethylene glycol （PEG） 6 000 nutrient solution for 20 h under continuous light [ 130 μmol/（m^2·s）]. The results showed that the contents of chlorophylls, carotenoids and soluble protein were decreased by osmotic stress with the decrease being more pronounced at 40% PEG, but that, at the same PEG concentration the decrease in the transgenic plants was significantly lower than that in the control plant. The activities of superoxide dismutase （SOD）, catalases （CAT）, ascorbate peroxidase （APX）, guaiacol peroxidase （GPX） and dehydroascorbate reductase （DHAR） were stimulated by PEG treatment. However, the increases were higher in PSA612-IPT transgenic plants than in the control plants, particularly at 40% PEG treatment. Lipid peroxidation （TBARS content） was increased by PEG treatment with the increase being much lower in transgenic plant than in the control plant. It could be concluded that the increases in the activities ofantioxidant enzymes including SOD, CAT, APX, GPX and DHAR were responsible for the delay of leaf senescence induced by osmotic stress.

Effects of 2, 4-Dichlorophenoxy Acetic Acid andLight on Growth of Gerbera (Gerbera jamesoniicv. Daxueju) Callus

This study was conducted to determine effects of 2,4-dichlorophenoxy acetic acid(2,4-D) and light on growth of gerbera(Gerbera jamesonii cv. Daxueju) callus. Callus was induced from both petiole and leaf explants of gerbera on Murashige and Skoog medium supplemented with 3% sucrose and various concentrations of 2,4-D and placed under light and dark. Callus induction percentage, callus size and callus fresh and dry weights were efficiently higher when using petiole as explant. MS medium supplemented with 1.5 mg/L 2,4-D showed the highest callus induction percentage of 96.70%. Callus induced under light had larger weight mass. It was indicated that 1.5 mg/L 2,4-D and light could promote growth of gerbera callus from petiole explant.

Paraquat Resistance in Leaf Discs of P_(SAG12)-IPT Modified Gerbera Is Relatedto the Activities of Superoxide Dismutase,Catalase,and Dehydroascorbate Reductase

In this paper, using in vitro leaf disc culture system, the changes of contents of chlorophylls, carotenoids, soluble protein, thiobarbituric acid reactive substance （TBARS）, and activities of antioxidant enzymes were investigated during the incubation of leaf discs of PSAG12-IPT modified gerbera in 0, 25, 50 μmol L^-1 paraquat （PQ） under continuous light intensity of 130 0tool m-2 s-1, compared with the control plant （wild type）. The results showed that PQ treatment significantly decreased the contents of chlorophylls, carotenoids, and soluble protein, therefore, promoted leaf senescence. However, the decreases in the leaf discs of modified gerbera were considerably smaller. The activities of superoxide dismutase （SOD）, catalase （CAT）, and dehydroascorbate reductase （DHAR） were significantly increased by PQ treatment and with the increasing of PQ concentration, particularly in the modified plants. The activities of ascorbate peroxidase （APX） and guaiacol peroxidase （GPX） could not be detected in the leaf discs of PQ treatments, which suggested that they were labile to the oxidative stress induced by PQ. As a product of lipid peroxidation, TBARS significantly increased in content with the increase of PQ concentration, while its concentration in the modified plants was significantly lower than that of control plants. Therefore, it could be concluded that the chimeric gene PSAG12-IPTtransfonnexi gerbera leaves had higher antioxidative potential, thus causing the delay of senescence under oxidative stress induced by PQ.

Identification and Expression of TOP3αin Gerbera hybrida

Meiotic recombination and the resulting novel allele combinations are fundamental to plant breeding and the identification of superior hybrids.However,the rate of meiotic crossovers is naturally suppressed below its potential ability,which prevents plant breeding efficiency.Nine suppressors of meiotic recombination have been identified in the model plant Arabidopsis and in other crop species.Mutations in these genes can lead to increased recombination frequency and could therefore potentially be used to create hyper-recombinant lines for ornamental breeding.In Gerbera hybrida,the anti-crossover factors remain elusive.In this study,we isolated and cloned TOP3αfrom flower buds of G.hybrida,and it encoded 935 amino acids with three conserved domains TOPRIM,TOP1Ac and zf-GR.Moreover,TOP3αwas the highest expressed at the flower bud stage,which coincided with the occurrence of meiotic recombination,suggesting that TOP3αis associated with the regulation of meiotic recombination in G.hybrida.

Cloning and Characterization of a Tyrosine Aminotransferase( TAT)Gene in Gerbera hybrida

In our previous study,a gene predicted to encode a Tyrosine aminotransferase( TAT) was found to be significantly up-regulated in root rot diseased Gerbera by transcriptome sequencing. To confirm the genes and investigate the function,we cloned the gene by RT-PCR and then conduct bioinformatic analyses. In this study,a 1 537 bp long c DNA sequence of this gene( named as Gh TAT) was firstly cloned,which contained a coding region of 1 233 bp,which was predicted to encode a protein of 410 amino acids. Bioinformatic analysis showed that the Gh TAT was a stable hydrophobic protein without signal peptide. Subcellular location prediction result indicated that this protein located in chloroplast,which is the biosynthesis position of tyrosine and the derived products of tyrosine biosynthesis pathway. Moreover,typical Tyrosine aminotransferase domain was found in this protein,indicating that it is a TAT. According to the TAT-based phylogenetic analysis and similarity analysis,the closest relationship and highest similarity was found between Gh TAT and Halianthus annuus TAT,which again verified the TAT property of Gh TAT. Tyrosine aminotransferase( TAT) is the first enzyme in tyrosine biosynthesis pathway,whose products include many antioxidant substances such as tocopherols and tocotrienols. The up-regulation of Gh TAT in root rot diseased gerbera suggests that it may play an important role in response to the root rot pathogen infection. In addition,60 phosphorylation sites( accounting for 14. 6%) were found in this protein,suggesting that the expression of this protein and its encoding gene were greatly influenced by the phosphorylation reactions.

(+)/(-)-Gerbeloid A,a pair of unprecedented coumarin-based polycyclic meroterpenoid enantiomers from Gerbera piloselloides:Structural elucidation,semi-synthesis,and lipid-lowering activity

A pair of coumarin-based polycyclic meroterpenoid enantiomers(+)/(-)-gerbeloid A[(+)-1a and(-)-1b]were isolated from the medicinal plant Gerbera piloselloides,which have a unique caged oxatricyclo[4.2.2.0^(3,8)]decene scaffold.Their planar and three-dimensional structures were exhaustively characterized by comprehensive spectroscopic data and X-ray diffraction analysis.Guided by the hypothetical biosynthetic pathway,the biomimetic synthesis of racemic 1 was achieved using 4-hydroxy-5-methylcoumarin and citral as the starting material via oxa-6πelectrocyclization and intramolecular[2+2]photocycloaddition.Subsequently,the results of the biological activity assay demonstrated that both(+)-1a and(-)-1b exhibited potent lipid-lowering effects in 3T3-L1 adipocytes and the high-fat diet zebrafish model.Notably,the lipid-lowering activity of(+)-1a is better than that of(-)-1b at the same concentration,and molecular mechanism study has shown that(+)-1a and(-)-1b impairs adipocyte differentiation and stimulate lipolysis by regulating C/EBPα/PPARγsignaling and Perilipin signaling in vitro and in vivo.Our findings provide a promising drug model molecule for the treatment of obesity.

不同保鲜剂组合对非洲菊切花保鲜效果的影响

以非洲菊(Gerbera jamesonii Bolus)鲜切花珍爱为试材,研究不同预处理液与瓶插保鲜液组合对丙二醛含量(MDA)、细胞膜透性、细菌含量及瓶插寿命的影响。结果表明,非洲菊切花经预处理液处理12 h后,MDA含量、细菌菌落数均显著低于对照(去离子水),且预处理能降低细胞膜的相对透性。非洲菊切花在瓶插处理期间MDA含量及细胞膜透性出现先下降后上升的变化趋势,瓶插14 d时达到最大值。花茎及瓶插液的细菌菌落数在瓶插过程中呈逐渐上升趋势,鲜花营养剂和免切通用鲜花营养液2种瓶插液表现了较好的抑菌效果。保鲜效果最佳的保鲜剂组合为可利鲜专业1号醒花液+鲜花营养剂,该处理可显著延长切花的瓶插寿命,其预处理及瓶插期间MDA含量、细胞膜透性和细菌菌落数的累积值均显著低于对照。

PRGL:A cell wall proline-rich protein containning GASA domain in Gerbera hybrida

PRPs (proline-rich proteins) are a group of cell wall proteins characterized by their proline and hy- droproline-rich repetitive peptides. The expression of PRPs in plants is stimulated by wounding and environmental stress. GASA (gibberellic acid stimulated in Arabidopsis) proteins are small peptides sharing a 60 amino acid conserved C-terminal domain containing twelve invariant cysteine residues. Most of GASAs reported are localized to apoplasm or cell wall and their expression was regulated by gibberellins (GAs). It has been reported that, in French bean, these two proteins encoding by two distinct genes formed a two-component chitin-receptor involved in plant-pathogen interactions when plant was infected. We cloned a full-length cDNA of PRGL (proline-rich GASA-like) gene which encodes a protein containing both PRP and GASA-like domains. It is demonstrated that PRGL is a new protein with characteristics of PRP and GASA by analyzing its protein structure and gene expression.

基于转录组的非洲菊GID1家族成员鉴定、分子特性与进化分析

非洲菊作为世界性鲜切花,具有观赏价值和经济价值。本研究应用生物信息学分析手段,在非洲菊全转录组中鉴定到5个赤霉素代谢相关受体蛋白GID1的家族成员(GID1-like1,GID1-like2,GID1-like3,GID1-like4,GID1-like5)。其理化性质分析结果显示:非洲菊GID1家族多为酸性,具有亲水性的非分泌蛋白,多数具有跨膜结构,其主要构成元件为α-螺旋和无规则卷曲;进化树分析结果表明,非洲菊GID1家族主要为四大分支,所挖掘到的GID1-like3和GID1-like4属于第一大分支,而GID1-like1、GID1-like2、GID1-like5同属于第三大分支;家族互作网络及蛋白保守结构域预测结果显示,GID1家族可能参与植物生长发育过程中赤霉素传导过程。研究结果将为揭示GID1家族在非洲菊赤霉素代谢途径中的生物学功能及非洲菊品种优化提供一定的理论基础。

NaCl胁迫对非洲菊幼苗生长与生理特性的影响

为探究切花非洲菊(Gerbera jamesonii)‘柯蒂奶油’和‘安娜’幼苗的耐盐生理作用机制,本试验以非洲菊幼苗为试验材料,利用不同浓度(0、100、125、150、200 mmol/L)的Na Cl溶液模拟盐渍土,研究其对非洲菊幼苗生长及生理特性的影响。结果表明:当非洲菊‘柯蒂奶油’和‘安娜’的Na Cl浓度分别在≤100 mmol/L和≤125 mmol/L时,低盐胁迫刺激非洲菊幼苗叶片,通过提高超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)等保护酶的活性来清除植物体内积累的活性氧(ROS),保持了细胞质膜的稳定,维持正常的渗透平衡与细胞代谢,促进非洲菊地上、地下部鲜重和叶绿素含量的增加;当非洲菊‘柯蒂奶油’和‘安娜’的NaCl浓度分别在≥125 mmol/L和≥150 mmol/L时,高盐胁迫导致植物体内活性氧过量累积,丙二醛(MDA)含量迅速增加,渗透代谢平衡被打破,致使细胞失水,严重抑制非洲菊幼苗的生长。因此,非洲菊‘柯蒂奶油’幼苗可耐≤100 mmol/L的Na Cl胁迫,‘安娜’幼苗可耐≤125 mmol/L的Na Cl胁迫。

A regulatory GhBPE-GhPRGL module maintains ray petal length in Gerbera hybrida

The molecular mechanism regulating petal length in flowers is not well understood.Here we used transient transformation assays to confirm that GhPRGL(proline-rich and GASA-like)—a GASA(gibberellic acid[GA]stimulated in Arabidopsis)family gene—promotes the elongation of ray petals in gerbera(Gerbera hybrida).Yeast one-hybrid screening assay identified a bHLH transcription factor of the jasmonic acid(JA)signaling pathway,here named GhBPE(BIGPETAL),which binds to the GhPRGL promoter and represses its expression,resulting in a phenotype of shortened ray petal length when GhBPE is overexpressed.Further,the joint response to JA and GA of GhBPE and GhPRGL,together with their complementary expression profiles in the early stage of petal growth,suggests a novel GhBPE-GhPRGL module that controls the size of ray petals.GhPRGL promotes ray petal elongation in its early stage especially,while GhBPE inhibits ray petal elongation particularly in the late stage by inhibiting the expression of GhPRGL.JA and GA operate in concert to regulate the expression of GhBPE and GhPRGL genes,providing a regulatory mechanism by which ray petals could grow to a fixed length in gerbera species.

基于转录组序列的非洲菊密码子偏好性分析

利用CodonW 1.4.2和在线软件CUSP分析非洲菊转录组13769条编码序列的密码子碱基组成、同义密码子相对使用度和密码子偏好性,并通过中性绘图分析、ENC-plot和PR2-plot分析影响密码子偏好性的因素。结果表明:非洲菊编码基因序列的密码子偏好性整体偏弱,影响密码子偏好性的主要因素为突变,同时确定UUG、UUU、UAU、AUU、UGU、GUU、AGA、GGU、UCU、UCA、CCA、ACC、GCU等13个最优密码子,最优密码子偏好以A/U结尾。本研究为进一步明确非洲菊密码子进化特征和遗传转化中最优密码子的选择提供参考依据。

民族药毛大丁草化学成分研究

目的:研究民族药毛大丁草Gerbera piloselloides(L.)Cass.的化学成分。方法:利用硅胶柱色谱、重结晶以及制备型HPLC等技术对毛大丁草的醇提物进行分离、纯化,采用NMR、MS波谱技术对化合物进行结构鉴定。结果:从毛大丁草的醇提物中分离得到20个化合物,分别鉴定为:3,5-bis(3,3-dimethylallyl)-4-hydroxyacetophen-one(1)、2-[(2S^(*))-6-acetyl-2,3-dihydro-5-ydroxybenzofuran-2-yl]prop-2-enyl-3-methylbutanoate(2)、adian-5-en-3α-ol(3)、烟曲霉三唑酯A(4)、亚油酸甲酯(5)、芝麻素(6)、5-acetyl-2-(2-hydroxyisopropyl)-7-(3,3-dimethylallyl)-2,3-dihydrobenzofuran(7)、shearene A(8)、4-羟基苯乙酮(9)、对羟基苯甲醛(10)、山柰酚(11)、3-吲哚甲醛(12)、熊果醛(13)、咖啡酸乙酯(14)、2,5-二羟基苯乙酮(15)、木犀草素(16)、咖啡酸(17)、阿魏酸(18)、熊果苷(19)、对苯二酚(20)。结论:其中,化合物1~14为首次从该植物中分离得到。

南方地区大棚种植非洲菊高温热害风险区划

以非洲菊“里奥内格罗”(Gerbera jamesonii Bolus, Rionegro)为研究对象,采用人工控制试验,以日/夜气温28℃/18℃为对照(CK),对非洲菊进行动态高温(32℃/22℃、35℃/25℃、38℃/28℃和41℃/31℃)和持续时间(4d、6d、8d和10d)处理,测定不同处理下非洲菊叶片的光合特性、荧光特性和衰老特性相关生理指标。依据相关性分析和主成分分析结果,构建适用于中国南方地区的设施非洲菊高温热害等级指标,并结合1990-2019年366个站点的气象资料和温室大棚小气候资料,利用BP神经网络模拟南方地区温室内日最高气温,以此开展南方非洲菊种植区大棚栽培高温热害风险区划。结果表明:(1)通过主成分分析提取Pn、Pmax、PItotal、Fv/Fm和POD作为关键指标构建设施非洲菊高温热害胁迫指数(HSI),将其分为轻度(0.20.6)三个等级,并以此确定其高温热害胁迫气象指标。(2)1990-2019年南方地区非洲菊种植区轻度高温热害爆发频率在0.19~0.90,以四川和云南东部及其以西地区居多;与轻度高温热害相比,中度高温热害在整个南方地区发生频率有所下降,主要发生在广西和广东地区,最高频率可达0.54。重灾发生频率也明显低于轻度,在0~0.58。(3)1990-2019年设施非洲菊高温热害在南方地区总体呈现南高北低的趋势,其中重庆、湖北、湖南、江西、广西、广东、福建和浙江等地,较大范围内为高风险区,而四川盆地以及云南东部和西部地区风险较低。其他区域为设施非洲菊高温热害中风险区。

应用SSR分子标记鉴定非洲菊F1代杂种的真实性

【目的】应用SSR分子标记技术鉴定非洲菊(Gerbera jamesonii Bolus)F1代杂种的真实性,以期为非洲菊新品种(系)杂种的真实性鉴定提供方法。【方法】选用非洲菊罗德里、热带草原及其65个正反交F1代杂种,部分自主选育非洲菊新品种(系)及其亲本为材料,从非洲菊转录组中发掘的65对SSR引物中筛选条带清晰、重复性好、亲本间无相同等位基因位点的引物,运用于非洲菊F1代杂种的真实性鉴定。【结果】65对SSR引物中,有26对引物在非洲菊亲本罗德里、热带草原间具有多态性,多态性比例达40%,其中,g24、g32、g38、g64这4对引物扩增非洲菊亲本间无相同等位基因位点,条带清晰可辨,扩增正反交后代都包含双亲的各一条带,都能将65个正反交后代鉴定为真杂种。引物g24、g04、g44、g39扩增非洲菊新品种(系)均包含双亲的各一条带,可分别将非洲菊新品种(系)明卉粉黛、明卉红颜、魅粉、幻彩鉴定为真杂种。【结论】SSR分子标记在非洲菊亲本中多态性丰富,可应用于非洲菊杂交后代真实性鉴定,能够有效辅助非洲菊新品种鉴定和选育。

火草叶片愈伤组织诱导及其分化研究

以火草叶片为外植体,研究了愈伤组织诱导与分化的方法。结果表明,火草无菌叶片在WPM+0.6 mg·L^(−1)6-BA+0.45 mg·L^(−1)NAA+30 g·L^(−1)蔗糖的培养基中,能诱导出直径0.5 cm、结构致密、质地硬的绿色愈伤组织,愈伤组织在WPM+0.75 mg·L^(−1)6-BA+0.15 mg·L^(−1)NAA+30 g·L^(−1)蔗糖的培养基中培养30 d分化出芽,平均每个分化的愈伤组织长出5.78个芽,芽苗转入1/2DKW+1.0 mg·L^(−1)IBA+0.1mg·L^(−1)NAA+30 g·L^(−1)蔗糖的培养基中培养30 d后,发育出5—13条不定根,且带有根毛的发达根系。

基于SSR标记的12个非洲菊品种指纹图谱构建及杂交F_(1)后代鉴定

【目的】基于SSR分子标记对12份非洲菊种质进行亲缘关系分析及部分种质杂交F_(1)后代真假杂种鉴定,以期为非洲菊种质资源鉴评及创新利用提供技术支撑。【方法】收集12个非洲菊种质资源,提取其基因组DNA后,利用50对SSR引物进行PCR扩增,通过检测相关多态性结果进行聚类分析和指纹图谱构建,以及部分品种杂交F_(1)后代鉴定。【结果】18对引物在12份非洲菊材料中共扩增出74个多态性等位变异片段,平均每对引物扩增出多态性等位变异片段4.1个。利用74个等位位点,构建了12份非洲菊种质资源的系统进化树,UPGMA聚类分析结果显示,当遗传系数为0.75时,可将受测的12份种质分为5组,Ⅰ组为‘云南红’‘大088’‘情人’,Ⅱ组为‘粉佳人’‘粉球’‘真爱’和‘福娃’,Ⅲ组为‘绣色’‘淑女’和‘黄球’,Ⅳ组和Ⅴ组均只包含1个品种,分别是‘紫水晶’和‘深圳5号’。筛选出GHSSR-1、GHSSR-18、GHSSR-20和GHSSR-21等4对引物,可完全区分12份种质;其中,后3对引物鉴定出兼具双亲特异位点的单株分别是Gh-5、Gh-4和Gh-1,单独1对引物的鉴定率为33%。且受检的3个单株均为真杂种,真杂种率为100%。【结论】成功构建12份非洲菊品种的指纹图谱,综合3对多态性较好的引物鉴定出3株非洲菊杂交F_(1)后代实生苗为真杂种,为非洲菊资源鉴评和创新利用提供可靠的SSR标记引物。

体外消化对大火草根作用于肠道菌群的影响

目的:从体外消化和肠道益生菌的角度,研究大火草根(Gerbera delavayi root,GDR)水提液经消化酶作用前后分别对益生菌的生长繁殖作用,以此揭示GDR是否可通过增殖益生菌来改善肠道健康,从而起到促进消化的作用。方法:通过采用体外模拟消化的方法,分析了消化前后的GDR对肠道益生菌的生长及代谢物的影响。结果:GDR水提液显著促进青春双歧杆菌、两歧双歧杆菌和嗜酸乳杆菌增殖的最适浓度分别为5、3、36 g/L,且分别能使三种益生菌增殖13.89%、40.53%、39.40%。同时,结果还表明,5和36 g/L的GDR水提液对金黄色葡萄球菌和大肠杆菌有显著的(P<0.05)抑制作用,最大抑菌圈分别为7.40和8.50 mm。上述结果表明GDR不但有利于益生菌的增殖,还可以有效抑制有害菌的生长,从而能够维持肠道健康。然而,实验结果还显示消化之后的GDR水提液对益生菌的生长无显著(P>0.05)影响。结论:一定浓度的GDR水提液在体外消化前能促进肠道益生菌的生长,同时还能有效抑制有害菌的生长,但经过体外消化后,其对益生菌的增殖无显著影响。