广西天南星属一新种

广西天南星属一新种刘寿养（广西中医学院,南宁５３０００１）关键词天南星属;桂西南星ＡＮＥＷＳＰＥＣＩＥＳＯＦＧＥＮＵＳＡＲＩＳＡＥＭＡＭＡＲＴ．ＦＲＯＭＧＵＡＮＧＸＩ￥ＬｉｕＳｈｏｕｙａｎｇ（ＧｕａｎｇｘｉＣｏｌｌｅｇｅｏｆＴｒａｄｉｔｉｏｎａｌＣｈ...     

四川天南星属(天南星科)一新种——川西南星

描述了四川西部天南星属(天南星科)植物一新种,即川西天南星.     

Cloning and Characterization of an Agglutinin Gene from Arisaema lobatum

A novel agglutinin gene was cloned from Arisaema lobatum using SMART RACE-PCR technology. The full-length cDNA of Arisaema lobatum agglutinin (ala) was 1078 bp and contained a 774 bp open reading frame encoding a lectin precursor (proproprotein) of 258 amino acid residues with a 23 aa signal peptide. ALA contained three mannose-binding sites (QXDXNXVXY) with two-conserved domains of 45% identity, ALA-DOM1 and ALA-DOM2. The three-dimensional structure of ALA was very similar to that of GNA (Galanthus nivalis agglutinin). ALA shared varying identities, ranging from 40% to 85%, with mannose-binding lectins from other species of plant families, such as Araceae, Alliaceae, Iridaceae, Lillaceae, Amaryllidaceae and Bromeliaceae. Genomic sequence of ala was also cloned using genomic walker technology, and it was found to contain three putative TATA boxes and eight possible CAAT boxes in the 5′-flanking region. No intron was found within the region of genomic sequence. Southern blot analysis indicated that the ala belonged to a multi-copy gene family. Expression pattern analysis revealed that the ala preferentially expressed in the tissues with the higher expression being found in spadix, bud, leaf, spathe and tuber. The cloning of the ala gene not only provides a basis for further investigation of its structure, expression and regulation mechanism, but also enables us to test its potential role in controlling pests and fungal diseases by transferring the gene into plants in the future.     

云南新植物

发表天南星属(天南星科)一新种苍山南星Arisaema cangshanense X.D.Dong,通泉草一新变种,白花通泉草Mazus japonica(Thunb.)O, Kuntze var.leucanthus X.D.Dong和光叶蔷薇一新变种,重瓣光叶蔷薇Rosa wichuraiana Crep.var.multipetala X.D.Dong     

法夏内生菌株D126产细胞毒活性物质布雷菲德菌素A的研究(英文)

药用植物法夏内生真菌D126,当进行液体培养时能产细胞毒活性物质,经核磁共振氢谱、碳谱和快原子轰击质谱确定,该物质为布雷菲德菌素A(BFA).进一步研究表明,BFA对人Burkitt's 淋巴瘤细胞株Raji、人肝癌细胞株HepG2和人非小细胞肺腺癌细胞株A549具有较强的抑制活性,对植物病原真菌黑曲霉和杨桃炭疽菌等具有抑菌活性.最后,对植物内生真菌产细胞毒活性物质BFA的生态意义进行了探讨.     

Contributions of diffusional limitation, photoinhibition and photorespiration to midday depression of photosynthesis in Arisaema heterophyllum in natural high light

Diurnal changes in photosynthetic gas exchange and chlorophyll fluorescence were measured under full sunlight to reveal diffusional and non‐diffusional limitations to diurnal assimilation in leaves of Arisaema heterophyllum Blume plants grown either in a riparian forest understorey (shade leaves) or in an adjacent deforested open site (sun leaves). Midday depressions of assimilation rate (A) and leaf conductance of water vapour were remarkably deeper in shade leaves than in sun leaves. To evaluate the diffusional (i.e. stomatal and leaf internal) limitation to assimilation, we used an index [1–A/A₃₅₀], in which A₃₅₀ is A at a chloroplast CO₂ concentration of 350 μ mol mol ^{? 1}. A₃₅₀ was estimated from the electron transport rate (J_T), determined fluorometrically, and the specificity factor of Rubisco (S), determined by gas exchange techniques. In sun leaves under saturating light, the index obtained after the ‘peak’ of diurnal assimilation was 70% greater than that obtained before the ‘peak’, but in shade leaves, it was only 20% greater. The photochemical efficiency of photosystem II ( Δ F/F_m ′ ) and thus J_T was considerably lower in shade leaves than in sun leaves, especially after the ‘peak’. In shade leaves but not in sun leaves, A at a photosynthetically active photon flux density (PPFD) > 500 μ mol m ^{? 2} s ^{? 1} depended positively on J_T throughout the day. Electron flows used by the carboxylation and oxygenation (J_O) of RuBP were estimated from A and J_T. In sun leaves, the J_O/J_T ratio was significantly higher after the ‘peak’, but little difference was found in shade leaves. Photorespiratory CO₂ efflux in the absence of atmospheric CO₂ was about three times higher in sun leaves than in shade leaves. We attribute the midday depression of assimilation in sun leaves to the increased rate of photorespiration caused by stomatal closure, and that in shade leaves to severe photoinhibition. Thus, for sun leaves, increased capacities for photorespiration and non‐photochemical quenching are essential to avoid photoinhibitory damage and to tolerate high leaf temperatures and water stress under excess light. The increased Rubisco content in sun leaves, which has been recognized as raising photosynthetic assimilation capacity, also contributes to increase in the capacity for photorespiration.     

三台花中的一新奇化合物--Serratumin A

从云南西双版纳产的三台花（Ｃｌｅｒｏｄｅｎｄｒｕｍ ｓｅｒｒａｔｕｍ ｖａｒ．ａｍｐｌｅｘｉｆｏｌｉｕｍ Ｍｏｌｄｅｎｋｅ）的地上部分分离到６个化合物,它们的结构通过波谱解析（包括２Ｄ ＮＭＲ技术）得到鉴定。其中化合物１是一新奇的单萜烯酸和单糖衍生物的缩合物,命名为ｓｅｒｒａｔｕｍｉｎ Ａ（１）;化合物２～６为首次从该植物中分离得到。     

Inhibition of monoamine oxidase B (MAO-B) by Chinese herbal medicines

Monoamine oxidase (MAO) catalyzes the oxidative deamination of biogenic amines accompaned by the release of H2O2. Two subtypes, MAO-A and MAO-B, exist on the basis of their specificities to substrates and inhibitors. The regulation of MAO-B activity is important in the treatment of neurodegenerative diseases. Twenty-seven species of plants used in traditional Chinese medicines, selected from an enthnobotanical survey, were used in an investigation of their inhibitory effect on MAO-B in rat brain homogenates. The 50% aqueous methanol extracts of four active extracts, Arisaema amurense, Lilium brownii var. colchesteri, Lycium chinense, and Uncaria rhynchophylla, exhibited the best activity and selectivity towards MAO-B with IC50 values of 0.44, 0.29, 0.40, and 0.03 mg/ml, respectively. A kinetic study of MAO-B inhibition by the four extracts using the Lineweaver-Burk plot for each active extract revealed the IC50 concentrations, and results show that: Ki = 0.59 mg/ml for A. amurense for the mixed-type mode, Ki = 0.58 mg/ml for L. brownii var. colchesteri for the mixed-type mode, Ki = 5.01 mg/ml for L. chinense for the uncompetitive mode, and Ki = 0.02 mg/ml for U. rhynchophylla for the uncompetitive mode. These may therefore be candidates for use in delaying the progressive degeneration caused by neurological diseases.     

异叶天南星苯丙氨酸解氨酶基因的克隆与蛋白结构分析

以异叶天南星（Arisaema heterophyllum Blume）为材料,采用逆转录PCR（RT-PCR）法扩增其苯丙氨酸解氨酶（Phenylalanine ammonia-lyase,PAL）基因AhPAL,获得该基因的开放读码框（ORF）,并通过系统的生物信息学软件分析AhPAL的结构和理化性质。结果显示,AhPAL的ORF全长为2184 bp,编码727个氨基酸;AhPAL与郁金香（Tulipa fosteriana W.Irving）PAL的亲缘关系最近,序列相似性达88%。空间结构模型分析结果显示,AhPAL为同型四聚体,每个单体由3个结构域组成,其中MIO结构域含有PAL酶家族的保守序列和Ala-Ser-Gly三肽活性中心,是AhPAL酶活性的决定性结构域。利用荧光定量PCR方法检测3个AhPAL Unigene在根、块茎和叶中的表达情况,发现它们在根中表达量均最高,而在叶和块茎中表达较低。