木薯干旱响应基因MeHDS1的克隆与分析

HD-Zip是植物中所特有的转录因子,在植物体响应环境因子过程中起着重要的作用。以木薯cDNA为模板,利用RT-PCR技术从木薯中克隆了一个HD-Zip家族成员基因全长,命名为MeHDS1。序列分析结果表明,MeHDS1具有822个氨基酸,分子量89.07 kD,等电点为5.79,其开放阅读框长2 469 bp,具有典型HD结构域及START结构域。该转录因子与棉花GL2蛋白的同源性很高,推断其同属第IV亚家族。MeHDS1蛋白内含有一个核定位信号,亚细胞定位试验结果也证明,MeHDS1蛋白定位于细胞核与细胞壁中。实时荧光PCR分析表明,该基因在木薯根部表达量最高,受干旱诱导上调表达。通过对其生物信息学分析及其在木薯中表达谱分析结果表明,MeH DS1可能作为转录调控因子参与木薯非生物胁迫应答反应。     

旱麦草EtAP2基因的克隆及其对干旱胁迫的响应表达

以旱麦草(Eremopyrum triticeum)为实验材料,利用RT-PCR技术从旱麦草叶片中克隆了1个AP2/ERF家族基因,命名为EtAP2(GenBank登录号KX622583)。EtAP2基因含有1 128bp开放阅读框,编码375个氨基酸,相对分子质量40.87kD,等电点为5.36。多序列比对和进化树分析表明,该基因编码蛋白具有2个AP2保守结构域,与小麦AP2/ERF家族蛋白具有较近的亲缘关系。实时荧光定量PCR分析表明,15%PEG 6000模拟干旱胁迫可诱导EtAP2基因在根和叶中表达,且在根中对干旱胁迫的响应大于叶片。研究表明,EtAP2可能参与旱麦草对干旱逆境胁迫应答的调节。     

木薯MeTPS9基因克隆及表达特性分析

旨在揭示木薯Me TPS9基因在干旱、低温、遮荫等非生物胁迫应答中的作用。用RT-PCR的方法从木薯叶片中克隆Me TPS9基因(Gen Bank登录号:MF276889),用MEGA软件构建系统进化树,用Dna SP软件分析基因结构变异,用Plant CARE分析启动子元件,用荧光定量PCR技术分析Me TPS9在不同组织中以及响应不同非生物胁迫的表达特性。结果显示,从木薯中克隆了一个TPS基因Me TPS9。该基因具有2 598 bp的开放阅读框,编码865个氨基酸,含有TPS家族保守结构域。系统进化树分析表明,Me TPS9与荠菜花和拟南芥中同源基因的亲缘关系较近,序列相似性分别为76.2%和75.6%。基因结构变异发现,木薯野生种和栽培种之间共有66个突变位点,其中11个为错义突变。启动子元件分析表明,Me TPS9含有干旱相关元件MBS、低温相关元件LTR、热胁迫相关元件HSE、以及ABA相关元件ABRE。实时荧光定量PCR分析表明,Me TPS9的表达量在须根中最高,在叶片中最低。而且,Me TPS9基因的表达能被干旱、低温、和遮荫处理显著诱导。Me TPS9在转录水平对木薯干旱、低温、和遮荫胁迫起调控作用,可作为候选基因进一步研究其在木薯抗逆中的作用。     

木薯MeNCED3基因克隆、结构变异及其表达分析

旨在揭示木薯MeNCED3基因在干旱等非生物胁迫应答中的作用。用RT-PCR的方法从木薯叶片中克隆MeNCED3基因,用MEGA软件构建进化树;用Dna SP软件分析基因结构变异,用荧光定量PCR技术分析MeNCED3在不同非生物胁迫下的表达特性。结果显示,从木薯中克隆了一个NCED基因MeNCED3,该基因具有1 803 bp的开放阅读框,编码600个氨基酸,含有NCED家族保守结构域。进化树分析表明,MeNCED3与杨树和杞柳中同源基因的亲缘关系较近,序列相似性分别达到83.9%和82.5%。基因结构变异发现,木薯野生种和栽培种之间共有8个错义突变,其中5个可能与MeNCED3的表达量有关。实时荧光定量PCR分析表明,MeNCED3在根中的表达量要远远高于叶片和茎。而且,MeNCED3的表达能被PEG、ABA和NaCl处理显著诱导。因此,MeNCED3在转录水平对木薯渗透胁迫、盐胁迫起调控作用,可作为候选基因进一步研究其在木薯抗旱中的功能。     

辣椒CaWRKY14转录因子的生物学特性研究

WRKY转录因子是植物响应病原菌胁迫最重要的转录因子之一,且参与抗病反应及信号传导通路的调控。为研究辣椒WRKY基因的生物学特征,以辣椒高抗疫病材料CM334为试材,克隆获得响应疫霉菌诱导的转录因子CaWRKY14。生物信息学分析表明,该基因DNA全长2 530 bp,cDNA全长1 662 bp,含有5个内含子,编码553个氨基酸,含有1个WRKY保守结构域,属于Group Ⅱ(b)。实时荧光定量表达分析表明,CaWRKY14不仅受ABA和疫霉菌胁迫诱导表达,且表达量分别在12 h和24 h时达到峰值,分别是对照的8.54和8.04倍,同时也受高盐、热激和干旱胁迫诱导。利用VIGS技术对CaWRKY14转录因子进行沉默后发现,抗病材料CM334接种疫霉菌后趋于发病。研究表明,CaWRKY14基因在辣椒响应疫霉菌胁迫进程中可能发挥着重要作用。     

木薯MeTPP1基因克隆、结构变异及其表达分析

旨在研究木薯MeTPP1基因在干旱、低温等非生物胁迫响应中的作用。用同源基因克隆的方法从木薯叶片中克隆MeTPP1基因,用MEGA软件构建Neighbor-joining系统进化树,用Dna SP软件分析基因结构变异,用实时荧光定量PCR技术分析MeTPP1基因在不同胁迫处理下的表达特性。结果表明,MeTPP1基因含有一个1 131 bp的开放阅读框,编码376个氨基酸,含有TPP家族保守结构域。系统进化树分析表明,MeTPP1与杨树和杞柳中同源基因的亲缘关系较近,序列相似性分别为77.8%和74.5%。基因结构变异发现,MeTPP1在木薯野生种和栽培种之间共有9个错义突变,它们可能与MeTPP1的表达有关。实时荧光定量PCR分析表明,MeTPP1表达量受到干旱、低温和ABA处理的响应。上述结果表明,MeTPP1在转录水平参与ABA介导的木薯干旱和低温胁迫,可作为候选基因进一步研究其在木薯抗逆中的功能。     

木薯MeASR基因克隆及表达分析

脱落酸-胁迫-成熟诱导蛋白(Abscisic acid-stress-ripening,ASR)在植物对非生物逆境胁迫的应答过程中发挥着重要作用。利用PCR技术从木薯中克隆了第一个ASR基因Me ASR,序列分析表明该基因开放阅读框(ORF)330 bp,编码109个氨基酸。多序列比对和进化树分析表明该基因所编码的蛋白具有ASR家族蛋白的保守结构域,与番茄ASR家族蛋白Sl ASR4具有较近的亲缘关系。亚细胞定位分析表明Me ASR定位在细胞核,实时荧光定量PCR分析表明该基因的表达显著受渗透胁迫和ABA诱导。结果表明,Me ASR可能作为转录因子参与木薯对干旱逆境胁迫应答及ABA信号调节。     

小麦TaWRKYⅢ-A37和TaWRKYⅡc-D2基因的克隆与表达分析

为了探究小麦(Triticum aestivum L.)WRKY基因的功能,采用同源克隆的方法,从小麦品种‘科农199’中克隆得到2个WRKY基因,分别命名为TaWRKYⅢ-A37和TaWRKYⅡc-D2,并对其进行生物信息学分析和不同逆境胁迫下的表达分析。生物信息学分析显示,TaWRKYⅢ-A37和TaWRKYⅡc-D2基因都含有2个内含子和3个外显子,分别编码206和138个氨基酸,编码蛋白都属于亲水性不稳定非分泌型的核蛋白。系统进化分析表明,TaWRKYⅢ-A37蛋白与其两个同源拷贝的亲缘关系最近,而TaWRKYⅡc-D2蛋白与粗山羊草亲缘关系最近。qRT-PCR结果表明,TaWRKYⅢ-A37和TaWRKYⅡc-D2基因在小麦根、茎和叶中均有表达,前者在根中表达量最高,后者在叶中表达量最高,二者均在茎中低表达;在苗期TaWRKYⅢ-A37基因受到PEG、H_2O_2和ABA胁迫后表达上调,NaCl处理后4～8 h内表达下调且低于对照表达水平,而且在灌浆期受到PEG、NaCl、H_2O_2和ABA胁迫后表达均上调;苗期TaWRKYⅡc-D2基因在NaCl、H_2O_2和ABA胁迫后表达下调,PEG处理2 h时表达上调且高于对照表达水平,并且在灌浆期经PEG和NaCl胁迫后表达下调,受H_2O_2和ABA胁迫后表达上调。该研究结果为深入探究TaWRKYⅢ-A37和TaWRKYⅡc-D2基因的抗逆功能奠定了理论基础。     

甘菊ClHSP70与ClHSP90基因的克隆及表达分析

该研究以甘菊(Chrysanthemum lavandulifolium)为实验材料,通过RT-PCR方法从甘菊转录组数据中分离出热激蛋白合成相关基因,命名为ClHSP70和ClHSP90。序列分析表明,ClHSP70基因ORF全长为2 559bp,编码852个氨基酸,蛋白功能区预测表明含有典型的HSP70蛋白NBD和SBD保守结构域;ClHSP90基因ORF全长为2 094bp,编码697个氨基酸,含有HATPase结构域和HSP90保守结构域。生物信息学分析表明,甘菊ClHSP70与大豆(Glycine max)和烟草(Nicotiana tomentosiformis)HSP70蛋白有较高的一致性,ClHSP90基因编码的氨基酸序列与紫茎泽兰(Ageratina adenophora)HSP90高度相似;实时荧光定量表达分析表明,在42℃处理不同时间,甘菊叶片中ClHSP70和ClHSP90基因表达均在0.5h时显著增加,1h达到最大值,2h后缓慢下降;不同组织表达分析表明,甘菊在42℃处理1h后,ClHSP70在成熟叶中的表达量显著高于嫩叶和根等其他组织;ClHSP90在成熟茎中的表达量最高。研究说明,ClHSP70和ClHSP90基因具有热激蛋白特征,参与了甘菊热胁迫应答过程,该研究结果为以后深入研究其基因功能奠定了基础。     

Foreign exploration for Scirtothrips perseae Nakahara (Thysanoptera: Thripidae) and associated natural enemies on avocado (Persea americana Miller)

Scirtothrips perseae Nakahara was discovered attacking avocados in California, USA, in 1996. Host plant surveys in California indicated that S. perseae has a highly restricted host range with larvae being found only on avocados, while adults were collected from 11 different plant species. As part of a management program for this pest, a “classical” biological control program was initiated and foreign exploration was conducted to delineate the home range of S. perseae, to survey for associated natural enemies and inventory other species of phytophagous thrips on avocados grown in Mexico, Guatemala, Costa Rica, the Dominican Republic, Trinidad, and Brazil. Foreign exploration efforts indicate that S. perseae occurs on avocados grown at high altitudes (>1500 m) from Uruapan in Mexico south to areas around Guatemala City in Guatemala. In Costa Rica, S. perseae is replaced by an undescribed congener as the dominant phytophagous thrips on avocados grown at high altitudes (>1300 m). No species of Scirtothrips were found on avocados in the Dominican Republic, Trinidad, or Brazil. In total, 2136 phytophagous thrips were collected and identified, representing over 47 identified species from at least 19 genera. The significance of these species records is discussed. Of collected material 4% were potential thrips biological control agents. Natural enemies were dominated by six genera of predatory thrips (Aeolothrips, Aleurodothrips, Franklinothrips, Leptothrips, Scolothrips, and Karnyothrips). One genus each of parasitoid (Ceranisus) and predatory mite (Balaustium) were found. Based on the results of our sampling techniques, prospects for the importation of thrips natural enemies for use in a “classical” biological control program in California against S. perseae are not promising.     

Molecular phylogeny of Phebalium (Rutaceae: Boronieae) and related genera based on the nrDNA regions ITS 1+2

Parsimony analyses of the internal transcribed spacer regions of nuclear ribosomal DNA (ITS 1 & ITS 2) for 38 taxa sampled from the Phebalium group (Rutaceae: Boronieae) and two outgroups confirm that, with the exception of Phebalium sensu stricto and Rhadinothamnus, six of the currently recognised genera within the group are monophyletic. The data indicate that Phebaliums. str. is paraphyletic with respect to Microcybe, and Rhadinothamnus is paraphyletic with respect to Chorilaena. Rhadinothamnus and Chorilaena together are the sister group to Nematolepis. Drummondita, included as an outgroup taxon, clustered within the ingroup as sister to Muiriantha and related to Asterolasia.The phylogeny suggests that the evolution of major clades within a number of these genera (e.g. Phebalium) relates to vicariance events between eastern and south-western Australia. Leionema is an eastern genus, with the most basal taxon being the morphologically distinct Leionema ellipticum from northern Queensland. Leionema also includes one species from New Zealand, but this species (as with some others) proved difficult to sequence and its phylogenetic position remains unknown. Taxonomic changes at the generic level are recommended.The authors wish to thank Paul G.Wilson, PERTH, for advice and discussion, and Paul Forster, BRI, for collecting and providing material of Leionema ellipticum. The project was supported by a Melbourne University Postgraduate Award (to BM), the Australian Biological Resources Study (ABRS), Australian Systematic Botany Society and Wolf Den (Australia) Investments.     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.

     

New species and new combinations in Peruvian Orchidaceae

seventeen new species and combinations are proposed in the generaChondrorhyncha, Cischweinfia, Cochlioda, Eloyella, Encyclia, Kefersteinia, Koellensteinia, Macroclinium, Rodriguezia, Solenidiopsis, andStenia. All new species are illustrated. A key is provided for 2-flowered species ofMacroclinium, PeruvianSigmatostalix, and PeruvianStenia. Solenidium (Solenidiopsis) peruvianum Schltr. is lectotypified.     

安徽牯牛降的丝孢菌Ⅰ

本文报导作者采自安徽枯牛降自然保护区的18种丝孢菌,分属于5个属,其中有3个新种:牛皮冻生尾孢(Cercospora paederiicola),山鸡椒假尾饱(Pseudocercospora litseae-cubebae),鸡血藤生假尾孢(P. millettiicola)和2个中国新纪录。文中对新种进行了描述及绘图,新记录种作了简要说明。研究的标本保存在中国科学院微生物研究所真菌标本室(HMAS)。     

Changes of dung beetle communities from rainforests towards agroforestry systems and annual cultures in Sulawesi (Indonesia)

Little is known about how tropical land-use systems contribute to the conservation of functionally important insect groups, including dung beetles. In a study at the margin of Lore Lindu National Park (a biodiversity hotspot in Central Sulawesi, Indonesia) dung-beetle communities were sampled in natural forest, young secondary forest, agroforestry systems (cacao plantations with shade trees) and annual cultures (maize fields), each with four replicates (n = 16 sites). At each site we used 10 pitfall traps, baited with cattle dung, along a 100 m transect for six 3-day periods. The number of trapped specimens and species richness at the natural forest sites was higher than in all land-use systems, which did not significantly differ. Each land-use system contained, on average, 75% of the species richness of the natural forest, thereby indicating their importance for conservation. However, a two-dimensional scaling plot based on NESS indices (m = 6) indicated distinct dung beetle communities for both forest types, while agroforestry systems and annual cultures exhibited a pronounced overlap. Mean body size of dung beetles was not significantly influenced by land-use intensity. Five of the six most abundant dung beetle species were recorded in all habitats, whereas the abundance of five other species was significantly related to habitat type. Mean local abundance and number of occupied sites were closely correlated, further indicating little habitat specialisation. The low dung beetle diversity (total of 18 recorded species) may be due to the absence of larger mammals in Sulawesi during historical times, even though Sulawesi is the largest island of Wallacea. In conclusion, the dung beetle fauna of the lower montane forest zone in Central Sulawesi appears to be relatively robust to man-made habitat changes and the majority of species did not exhibit strong habitat preferences.     

Taxonomic status of the species of the green algal genusNeochloris

Komárek has recently reviewed the various species assigned to the green algal genusNeochloris Starr (Chlorococcales, Chlorococcaceae) and removed those with uninucleate vegetative cells to a new genus,Ettlia. Watanabe & Floyd, unaware ofKomárek's work, also reviewed the species ofNeochloris and distributed them among three genera—Neochloris, Chlorococcopsis gen. nov., andParietochloris gen. nov.—on the basis of details of the covering of the zoospore and the arrangement of the basal bodies of the flagellar apparatus. This paper reconciles these two treatments and makes additional recommendations at the ranks of genus, family, order, and class.     

Die GattungKarschia — Bindeglied zwischen bitunicaten Ascomyceten und lecanoralen Flechtenpilzen?

The genusKarschia, in the earlier sense, including saprophytes and parasites on lichens, has been thought to be a non-lichenized parallel genus of the lichen genusBuellia. Modern workers included it on the one hand inBuellia, on the other hand combined it with bitunicate ascomycetes. It is now proved thatKarschia is heterogeneous and contains but superficially similar members both of the genusBuellia of theLecanorales and of typical or masked bitunicateAscomycetes. Therefore, it can not be regarded as a link betweenLecanorales andDothideales. The type species ofKarschia belongs to theDothideales.