矿质营养缺乏对黄瓜生理生化特性的影响

通过营养液栽培,研究不同矿质营养的缺乏对黄瓜叶片组织生理生化特性的影响。结果表明,缺铜对植株生理影响最大,在各处理中,叶片组织的可溶性糖含量最低,木质素含量也处于较低水平,而相对电导度则最高,所测定的4种保护酶(POD、PPO、PAL、SOD)活性也最低。其次是锌,缺锌造成了相对电导度的增加,可溶性糖含量和木质素含量的下降,除PAL活性外,其余3种酶活性也处于次低的位置。缺锰主要导致了叶片组织可溶性糖含量、木质素含量以及PAL活性的较大幅度的下降。缺钙主要降低了叶片组织中可溶性糖含量和SOD活性。比较而言,硼和铁的缺乏影响较小。     

苎麻CCoAOMT基因cDNA反义转化模式烟草''WS38''

苎麻咖啡酰辅酶A氧甲基转移酶(CCoAOMT)是其木质素合成过程的一种关键酶,运用克隆的该酶基因cDNA及植物表达载体pBI121、pWM101,分别构建了35S启动子控制的苎麻CCoAOMT基因反义cDNA基因质粒(pBI121-antiBnCCoAOMT)和cDNA全长表达质粒(pWM101-BnCCoAOMT),并通过根癌农杆菌介导法将其转化至模式烟草WS38,获得了转基因烟草.对转基因植株进行分子分析和组织学初步研究表明,转反义RNA基因植株叶柄木质素含量较野生烟草或转正义基因烟草叶柄木质素含量降低.说明运用反义RNA技术对CCoAOMT基因的表达进行基因工程调控,一定程度上可以对木质素的合成产生干扰,为获得低木质素或木质素组分改良的苎麻基因工程奠定基础.     

寡糖对向日葵叶片细胞病程相关蛋白及细胞壁物质的诱导作用

用寡糖对向日葵叶片进行喷雾,研究了该寡糖对向日葵叶片细胞内几丁质酶和β-1,3-葡聚糖酶2种病程相关蛋白(PRs蛋白)以及木质素、富含羟脯氨酸蛋白(HRGP)2种细胞壁物质含量的影响.结果表明,经寡糖处理后,向日葵叶片中β-1,3-葡聚糖酶和几丁质酶的活性均升高,最高值分别比同期CK增加36.38%和6.35%;木质素及HRGP含量也诱导增加,最高值分别比同期CK显著增加39.15%和47.13%.在寡糖处理后接种病原菌的向日葵叶片中,β-1,3-葡聚糖酶及细胞壁物质被诱导合成,且合成量均较单独寡糖处理与单独接种锈菌处理要高.研究发现,诱导向日葵幼苗叶片的几丁质酶、β-1,3-葡聚糖酶活性增强和细胞壁木质素、HRGP含量增加,可能是寡糖预处理增强向日葵抗锈性的内在机制.     

刺芹侧耳栽培料及菌体中漆酶介体分子的挖掘

虽然真菌能够分泌漆酶从木质素中获取碳源,然而纯化后真菌漆酶降解木质素的能力却极低。本文利用萃取方法提取刺芹侧耳栽培料及菌体中可溶性化合物,通过快速漆酶介体体系（LMS）动力学实验确定其对漆酶催化氧化反应的促进或抑制能力,进一步利用HPLC-MS和代谢组学差异分析的方法从最高活性萃取液的柱层析组分中挖掘潜在的活性成分。研究结果表明栽培料中可能含有活性介体成分,生物信息学XCMS代谢产物组分析揭示了CTE05分离组分中富含的木质素代谢产物,涉及到软木脂单体合成、香豆素合成、丁香油酚或异丁香油酚合成、质体醌醇合成、由苯丙氨酸合成硫代葡萄糖苷和安息香酸合成等代谢途径。最后讨论了其中11种潜在的天然介体分子物理化学性质,其中4种为已有文献报道的天然介体小分子。本研究暗示木质素降解与合成代谢在分子机制上存在有某种联系,相关的代谢产物可能参与了真菌降解木质素的代谢过程。     

UV-B辐射增强对反枝苋形态、生理及化学成分的影响

通过大田盆栽实验,研究了2种增强的UV-B辐射对双子叶C4植物反枝苋(Amaranthus retroflexus)形态、生理、生物量分配及化学成分的影响.结果表明:增强UV-B辐射处理下分枝数、叶片数、高度和基径均没有显著变化.高、低剂量的UV-B处理均导致过氧化氢酶(CAT)活性显著高于对照组(P＜0.05),但对超氧化物歧化酶(SOD)活性无影响,低剂量辐射下过氧化物酶(POD)活性显著高于对照而高剂量辐射下无显著变化,同时丙二醛(MDA)含量随辐射剂量的增加而显著增加(P＜0.05).收获期低剂量辐射处理下的资源分配模式发生变化,分配到叶片的生物量比例显著增加,而分配到根的比例显著减小,但高剂量辐射对生物量分配无影响.UV-B辐射处理下根、茎、叶部所检测的大多数化学成分与对照相比均有显著变化:叶片中可溶性蛋白、木质素和脂肪,根中木质素,茎中纤维素、木质素含量在辐射处理下显著高于对照;叶片中淀粉,茎中可溶性糖、淀粉和脂肪含量在辐射处理下显著低于对照(P＜0.05).     

西瓜嫁接体发育中木质素合成及代谢相关酶活性的变化

研究了西瓜/葫芦嫁接体发育过程中砧木和接穗部分木质素含量及其代谢相关酶的活性变化.结果表明,嫁接体发育过程中木质素生物合成加快,砧木及接穗部分的过氧化物酶(POD)、过氧化氢酶(CAT)、苯丙氨酸解胺酶(PAL)、肉桂醇脱氢酶(CAD)等的活性均明显高于对照,接穗和砧木中POD活性在15 d内持续升高,H2O2含量和CAT活性于嫁接后9~12 d出现高峰,砧木中PAL于9 d时有活性高峰而接穗一直保持较高活性而没有活性高峰,木质素含量和CAD活性持续增长,葫芦砧木木质素的代谢水平高于西瓜接穗.     

云南野生稻籽粒淀粉合成关键酶活性测定

为研究云南3种野生稻直链淀粉合成机制并利用其直链淀粉含量较低的优良品质,以云南3种野生稻和4种当地栽培稻为材料,研究野生稻灌浆期籽粒4种淀粉合成关键酶(包括ADPG焦磷酸化酶、可溶性淀粉合成、颗粒凝结型淀粉合成酶、淀粉分支酶)活性变化。结果表明,野生稻中4种淀粉合成酶的变化趋势与栽培稻相似,但活性有较大差别。颗粒凝结型淀粉合成酶的活性与直链淀粉含量呈正相关,说明在野生稻中同样是由颗粒凝结型淀粉合成酶控制直链淀粉的合成。同时发现在同一灌浆期,同种材料中可溶性淀粉合成酶和淀粉分支酶的活性变化呈相反趋势,推测这两种酶之间可能在淀粉合成过程中存在某种反馈调节机制。     

镉胁迫对水稻颖果充实和淀粉合成关键酶活性的影响

盆栽试验研究了Cd胁迫对水稻(扬稻6号和粳稻941)颖果充实过程中颖果鲜千重、可溶性糖和淀粉含量以及淀粉合成关键酶活性的影响,结果显示Cd胁迫:(1)降低了颖果淀粉合成关键酶的活性,缩短了颖果维持上述酶活性的天数;(2)降低了颖果可溶性糖的含量;(3)颖果灌浆减慢,鲜重、干重增加速率减缓,灌浆的天数变短,最终成熟颖果干重降低.说明,淀粉合成关键酶活性下降和维持活性的时间缩短使淀粉等贮藏物质的合成和积累降低是Cd胁迫降低颖果粒重的原因之一.     

中间锦鸡儿CCR2和CCR3基因的克隆和功能鉴定

肉桂酰辅酶A还原酶(cinnamoyl-CoAreductase,CCR)是催化木质素合成特异途径的第一个限速酶,对木质素的合成起关键作用。从中间锦鸡儿中克隆了两个CCR基因,CiCCR2和CiCCR3,其中CiCCR2基因开放阅读框为897bp,编码299个氨基酸,CiCCR3基因开放阅读框为966bp,编码322个氨基酸。过表达CiCCR2和CiCCR3转基因拟南芥株系幼苗期和成熟期木质素含量均高于野生型,组织化学染色也表明转基因株系木质素积累较野生型拟南芥多,且转基因株系鲜重和干重显著高于野生型。     

茉莉酸甲酯诱导烟草幼苗抗炭疽病与PAL活性及细胞壁物质的关系

探讨了茉莉酸甲酯(methyl jasmonate, Me-Ja)诱导烟草幼苗抗炭疽病与苯丙氨酸解氨酶(PAL)活性、木质素和富含羟脯氨酸蛋白(HRGP)含量的关系。 Me-Ja处理烟草幼苗不仅可以提高幼苗抗炭疽病的能力,而且明显提高幼苗的PAL活性、木质素和HRGP含量; 3个不同抗性品种的烟草幼苗的PAL酶活性、木质素和HRGP含量三者与感病程度之间的负相关都达到显著水平,表明PAL、木质素和富含羟脯氨酸蛋白(HRGP)在茉莉酸甲酯诱导抗病中起关键作用。     

芦笋种质资源遗传多样性的RAPD分析

采用RAPD技术对国内外43个芦笋品种的遗传多样性进行分析.从60个随机引物中筛选出12个有效引物,共扩增出183条DNA片段,其中170条为多态性条带,约占总数的92.92%;平均每个引物扩增DNA带数超过15条.结果表明,43份材料的Nei氏相似系数分布在0.407～0.931之间,平均为0.765,可见遗传多样性相对偏低.对所有材料进行聚类分析,在Coefficient=0.77处划等值线,可将参试样品划分为8大类群.其中Jwc1、Purple Passion、鲁芦笋1号等6个品种各单独列为1个类群,其余的被分为2个类群.     

Resistance to Asparagus virus 1 in the Wild Relative Asparagus amarus

Five asparagus cultivars, three breeding lines and the wild relative Asparagus amarus were tested for natural infection by Asparagus virus 1 (AV‐1) in experimental fields at two locations over 3 and 4 years, respectively. In the first year after re‐planting the annual crowns in the field, more than 90% of tested plants of cultivars were infected by AV‐1. In the third and fourth year, 100% of tested plants of cultivars were AV‐1 infected. In comparison, all plants of the wild relative A. amarus were completely free of AV‐1, suggesting a high level of resistance. Additionally, 1‐year‐old glasshouse‐cultivated plants of A. officinalis and A. amarus were placed in an AV‐1 provocation cabin under field conditions. Seven months later, 100% of the A. officinalis plants showed a high virus concentration in ELISA, whereas no AV‐1 was detectable in the A. amarus plants. This result was confirmed by highly sensitive AV‐1‐specific RT‐PCR. To exclude vector resistance, the feeding behaviour of green peach aphid Myzus persicae was tested over 12 h using the electrical penetration graph method. Both asparagus genotypes were accepted by the aphids as potential hosts, but the feeding time was significantly longer on A. amarus. A genetic distance analysis of the various cultivars of Asparagus officinalis and selected wild relatives of the JKI collection was carried out, resulting in a clear discrimination of cultivars and wild relatives, especially A. amarus. The potential breeding value of the putative resistance carrier is discussed.     

Isolation and Identification of Fructo-oligosaccharides in Roots of Asparagus (Asparagus officinalis L.)

Eight fructo-oligosaccharides were isolated from purified oligosaccharide fractions of the roots of Asparagus officinalis L. (Liliaceae). By examination of constituent sugars, gas-liquid-chromatographic analysis of methyl derivatives, and investigation of partial acid hydrolyzates and products of β-fructofuranosidase action, they were confirmed to be 1^F(1-β -fructofuranosyl)_n sucrose [n = 1 (1-kestose), 2 (nystose), and 3], 6^G (1-β-fructofuranosyl)_n sucrose [n = 1 (neokestose), 2, and 3], 1^F,6^G-di-β-fructofuranosyl sucrose, and a new pentasaccharide 1^F (1-β-fructofuranosyl)₂-6^G-β-fructofuranosyl sucrose.     

A Bitter Principle of Asparagus: Isolation and Structure of Furostanol Saponin in Asparagus Storage Root

During an examination of components contributing to the bitter taste of asparagus bottom cut (Asparagus officinalis L.), two new furostanol saponins were isolated from roots extractives. Their chemical structures were established as 5β-furostane-3β,22,26 triol-3-O-β-d-glucopyranosyl (1→2)-β-d-glucopyranoside 26-O-β-d-glucopyranoside and 5β-furostane-3β,22,26 triol-3-O-β-d-glucopyranosyl (1→2) [β-d-xylopyranoxyl (1→4)]-β-d-glucopyranoside 26-O-β-d-glucopyranoside respectively.     

N-Carboxymethyl-l-serine,a New Acidic Amino Acid from Asparagus (Asparagus officinalis) Shoots

A strongly acidic amino acid—N-carboxymethyl-L-serine—, not previously known in nature, has been isolated from asparagus (Asparagus officinalis) shoots. Some unique properties of this amino acid, such as a much bigger mobility to anode on high voltage paper electrophoresis (pH 3.6) than aspartic acid and characteristic changes of NMR spectra in aqueous solution with various pD, were discussed in relation to its structure.     

In Vitro Preservation of Asparagus Officinalis

A simple systems for in vitro storage of health asparagus germplasm was developed. High percent (90 %) of shoots cultured in a standard multiplication medium were maintained viable in vitro at 5 °C in darkness for 12 months. This percent was decreased to 60 % when cultures were stored for 18 months. At normal temperature, shoots and callus cultures also survived for 1 year under osmotic stress on medium containing 40 g dm^-3 mannitol.     

Steroidal saponins from Asparagus acutifolius

Six new steroidal saponins (1-6) were isolated from the roots of A. acutifolius L., together with a known spirostanol glycoside (7). Their structures were elucidated mainly by extensive spectroscopic analysis (1D and 2D NMR, FABMS and HRESIMS). Compounds 4-7 demonstrated antifungal activity against the human pathogenic yeasts C. albicans, C. glabrata and C. tropicalis with MICs values between 12.5 and 100 microg/ml.     

用形态与分子标记研究石刁柏种质资源遗传多样性

采用RAPD分子标记结合形态学指标对43份石刁柏种质资源的遗传多样性进行评价。田间试验相关分析表明,茎粗、林高、茎数与产量呈极显著正相关,三者是影响石刁柏产量的主要因素。茎粗、株高、产量与一级笋率呈显著正相关。花梗全紫的石刁柏一级笋率相对较高。根据形态学指标将材料分为7大类。在分子标记中,从60个随机引物中筛选出12个能产生清晰、稳定可重复DNA片段的引物,对供试材料进行RAPD扩增。在供试材料中共获得183条扩增产物,产生的DNA片段大小主要分布在200～1600bp之间,其中170条具有遗传多态性,约占总数的92．92％。各基因型间的Nei氏相似性系数分布在0．407～0．931之间,平均相似性为0．765,可见石刁柏各基因型之间的遗传多态性较为丰富。经UPGMA方法建立的树状图,可将参试品种划分为8大类群。形态学指标与遗传多样性指标的相关分析结果显示：分枝节间距、花梗颜色、每簇拟叶数、最长分枝长度、茎粗5个形态学指标与遗传多样性指标之间存在一定的相关性。     

Lignin Deposition and Effect of Postharvest Treatment on Lignification of Green Asparagus (Asparagus officinalis L.)

To understand how lignin synthesis is regulated after harvest, detached green asparagus stalks (Asparagus officinalis L.) were treated with 1 μl l⁻¹ of 1-methylcyclopropene (1-MCP), 50 μg l⁻¹ gibberellic acid (GA₃), 2% (v:v) ethanol or 1 μl l⁻¹ ethylene. The results showed that lignin concentration in asparagus stalks stored at room temperature rapidly increased. Three conventional precursors of lignin, 4-hydroxycinnamic acid (coumaric acid), 3,4-dihydroxycinnamic acid (caffeic acid) and 4-hydroxy-3-mythoxycinnamic acid (ferulic acid), were found to be the major phenolics in the asparagus stalks. Furthermore, the concentrations of O₂⁻ in asparagus stalks steadily increased during the storage. Deposition of lignin in harvested asparagus was significantly reduced by treating the stalks with GA₃, 1-MCP or ethanol. The concentration of lignin in stalks treated with GA₃, 1-MCP or ethanol was 32, 20 or 27% lower, respectively, than in controls 3 days after treatment. Treating stalks with ethylene enhanced lignin synthesis (p<0.05). The concentration of total phenol in stalks was also significantly reduced by GA₃, 1-MCP and ethanol, but was enhanced by ethylene treatment. However, the concentration of active oxygen (O₂^−⋅) in stalks was significantly reduced by treatment with GA₃, 1-MCP and ethanol, but was enhanced by treatment with ethylene. Our study show that postharvest treatment with 1-MCP, GA₃ or ethanol may be applied to improve the quality of green asparagus.     

Propagation of Asparagus racemosus through tissue culture

Murashige and Skoog's medium with 2, 4-D and kinetin induced callus in the shoot segments of Asparagus racemosus. Regeneration of shoot buds and clonal multiplication of excised shoots through proliferation of nodal buds could be achieved by the use of IAA and BAP in the medium. Rooting was achieved with half strength MS basal medium plus IBA. Complete plants with cladode, crown and root systems were developed in hormone free medium. The plants were successfully transferred to soil.