The sodium cycle. III. Vibrio alginolyticus resembles Vibrio cholerae and some other vibriones by flagellar motor and ribosomal 5S-RNA structures

An electron microscopic study of the basal bodies of the Vibrio albinolyticus flagellum revealed a four-disc structure. The diameters of the two discs localized closer to the cytoplasmic membrane proved to be about 2-fold shorter than those of the two others. In this respect the basal body of V. alginolyticus resembles very much that of V. cholerae described by Ferris and co-workers. The sequence of the V. alginolyticus ribosomal 5S-RNA showed that it is similar to those of V. cholerae, V. harveyi and some other vibriones. On the basis of the 5S-RNA sequences, a dendrogram of prokaryotes is presented. It confirmed the suggestion that V. alginolyticus is a typical representative of Vibrionaceae rather than a ‘monster’ greatly differing from other vibriones. Possible evolutionary relation of various bacterial species possessing the primary Na⁺ pumps is discussed.     

Rapid turnover and species-specificity of vomeronasal pheromone receptor genes in mice and rats

Pheromones are used by individuals of the same species to elicit behavioral or physiological changes, and they are perceived primarily by the vomeronasal organ (VNO) in terrestrial vertebrates. VNO pheromone receptors are encoded by the V1r and V2r gene superfamilies in mammals. A comparison of the V1r and V2r repertoires between closely related species can provide significant insights into the evolutionary genetic mechanisms responsible for species-specific pheromone communications. A total of 137 putatively functional V1r genes of 12 families were previously identified from the mouse genome. We report the identification of 95 putatively functional V1r genes from the draft rat genome sequence. These genes map primarily to four blocks in two chromosomes. The rat V1r genes can be phylogenetically grouped into 10 families, which are shared with mouse, and 2 new families, which are rat-specific. Even in many shared families, gene numbers differ between the two species, apparently due to frequent gene duplication and pseudogenization after the separation of the two species. Molecular dating suggests that most of the rat V1r families emerged before or during the radiation of mammalian orders, but many duplications within families occurred as recently as in the past 10 million years (MY). Our results show that the evolution of the V1r repertoire is characterized by exceptionally fast gene turnover via gains and losses of individual genes, suggesting rapid and substantial changes in pheromone communication between species.     

Integrative taxonomy and phylogeny of leafless Vanilla orchids from the South-West Indian Ocean region reveal two new Malagasy species

The leafless Vanilla species complex from the South-West Indian Ocean (SWIO) region has long been a taxonomic challenge, due to limited patterns of morphological differentiation and an absence of variation within chloroplast sequences. This complex includes seven known morphospecies: V. madagascariensis, V. bosseri, V. decaryana, and V. perrieri endemic to Madagascar, V. humblotii presumed as endemic to the Comoros Archipelago, but also present in Madagascar, V. roscheri from the East African coast, and V. phalaenopsis endemic to Seychelles. A previous population genetic study using microsatellite markers allowed us to distinguish, in addition to the five recognized Malagasy taxa, two other genetic clusters present in the East of the island. An integrative taxonomy approach was therefore conducted by combining microsatellite and morphological data used in the previous study with new data sets, and by adding ITS sequencing data, to validate the taxonomic level of these Malagasy genetic clusters and unravel phylogenetic relationships between SWIO species. As a result, based on phylogenetic, genotypic and morphological evidence, nine species were discriminated in the SWIO region, including seven in Madagascar, with two new eastern species. The leafless Vanilla group originated and diversified in Madagascar, from an ancestor of African descent, with three subsequent independent colonization events from Madagascar to the other territories of SWIO within the two main lineages (white versus yellow flower species). The new Malagasy species, V. allorgeae Andriamihaja & Pailler sp. nov., and V. atsinananensis Andriamihaja & Pailler sp. nov., are described and a new identification key is proposed.     

中国东北无隔藻科的研究

本文报道了中国东北无隔藻科18种2变种2变型,其中有1新种1新变型2新组合,中国记录4种1变种,东北新记录3种,其中大部分种类结合室内培养对种的形态变化进行了研究。本文还对东北无隔藻科植物的生态分布、分类上混乱的问题进行系统的整理和讨论。     

山西省苹果树腐烂病菌的种群结构分析

为明确山西省苹果树腐烂病菌的分布与组成,本研究采集并分离得到来自山西省8个苹果树种植区有代表性的78株腐烂病菌,通过形态特征观察及利用2个DNA片段（ITS和EF1α）构建系统发育树等方法对其遗传结构进行了研究。结果表明山西省苹果树腐烂病由苹果黑腐皮壳菌Valsa mali和梨黑腐皮壳菌Valsa pyri 2个致病种所致,其中V. pyri是优势种,分布于山西省各个苹果树种植区,占菌株总数的58.97%。以山西省8个苹果树种植区腐烂病菌各个种的相对频率进行聚类分析,欧式距离9作为聚类分割点将其种群结构分为3类。第Ⅰ类包括忻州、朔州2个苹果树种植区,V. pyri为该类型苹果树种植区的致病菌、相对频率为100%。第Ⅱ类包括晋城、长治、临汾、太原、运城5个苹果树种植区,V. pyri是这5个种植区的优势种。第Ⅲ类包含晋中1个苹果树种植区,V. mali是该种植区的优势种。     

The sodium cycle. II. Na-coupled oxidative phosphorylation in Vibrio alginolyticus cells

The role of Na⁺ in Vibrio alginolyticus oxidative phosphorylation has been studied. It has been found that the addition of a respiratory substrate, lactate, to bacterial cells exhausted in endogenous pools of substrates and ATP has a strong stimulating effect on oxygen consumption and ATP synthesis. Phosphorylation is found to be sensitive to anaerobiosis as well as to HQNO, an agent inhibiting the Na⁺-motive respiratory chain of V. alginolyticus. Na⁺ loaded cells incubated in a K⁺ or Li⁺ medium fail to synthesize ATP in response to lactate addition. The addition of Na⁺ at a concentration comparable to that inside the cell is shown to abolish the inhibiting effect of the high intracellular Na⁺ level. Neither lactate oxidation nor Δω generation coupled with this oxidation is increased by external Na⁺ in the Na⁺-loaded cells. It is concluded that oxidative ATP synthesis in V. alginolyticus cells is inhibited by the artificially imposed reverse ΔPNa, i.e., [Na⁺]_in > [Na⁺]_out. Oxidative phosphorylation is resistant to a protonophorous uncoupler (0.1 mM CCCP) in the K⁺-loaded cells incubated in a high Na⁺ medium, i.e., when ΔpNa of the proper direction ([Na⁺]_in < [Na⁺]_out) is present. The addition of monensin in the presence of CCCP completely arrests the ATP synthesis. Monensin without CCCP is ineffective. Oxidative phosphorylation in the same cells incubated in a high K⁺ medium (ΔpNa is low) is decreased by CCCP even without monensin. Artificial formation of ΔpNa by adding 0.25 M NaCl to the K⁺-loaded cells (Na⁺ pulse) results in a temporary increase in the ATP level which spontaneously decreases again within a few minutes. Na⁺ pulse-induced ATP synthesis is completely abolished by monensin and is resistant to CCCP, valinomycin and HQNO. 0.05 M NaCl increases the ATP level only slightly. Thus, V. alginolyticus cells at alkaline pH represent the first example of an oxidative phosphorylation system which uses Na⁺ instead of H⁺ as the coupling ion.     

Secondary metabolites from Centaurea grisebachii ssp. grisebachii

The aerial parts of Centaurea grisebachii ssp. grisebachii, a Greek endemic species belonging to section Acrolophus (Cass.) DC., were investigated for the occurrence of sesquiterpene lactones. The eudesmanolide, 4-epi-malacitenolide was the major compound. In addition to the sesquiterpene lactones, five flavonoid aglycons, two lignans, one nor-isoprenoid and one sterol were found.     

东北地区野豌豆属Vicia L.物种生物学研究——Ⅰ.染色体数目及其分类学意义

本文首次全面地报道了东北地区野豌豆属植物染色体数目。结果如下:Vicia cracca group. 2n=12; V. amurensis Oett. 2n=12; V. amocna Fisch. ex DC. 2n=24; V. amocna var. oblongifolia Reqel 2n=12; V. amoena var. scricca Kitag. 2n=12; V. geminiflora Trautv. 2n=14; V. japonica A. Gray 2a=24; V. pseudorobus Fisch, et C. A. Mey 2n=12; V. multicauhs Ledeb. 2n=12; V. venosa (Willd.) Maxim, 2n-12; V. ramuliflora (Maxim.) Ohwi 2n=12, 24; V. unijuga A. Br. 2n=12, 24.结果表明该地区野豌豆种类以x=6为主,并以该基數形成较高频率的多倍体类群。根据染色体资料,对于长期存在争议的种下处理或近緣种类的划分,作者提出了新的见解。     

Is the social parasite Vespa dybowskii using chemical transparency to get her eggs accepted?

Both avian and insect cuckoos must trick their hosts into accepting foreign eggs. In birds this is achieved through egg mimicry. Within the hornets the only known social parasite is the rare Vespa dybowskii. We investigated how the V. dybowskii queen induces tens or hundreds of host workers to accept her eggs and offspring. Since hydrocarbons function as recognition cues in social insects, we investigated these compounds from the surface of eggs and workers of V. dybowskii, both host species (V. simillima and V. crabro) and an additional four non-host species. We found that chemical mimicry of the hosts’ colony odour and their eggs normally associated with wasps was not being employed by V. dybowskii. Chemical insignificance is also unlikely as the amounts of hydrocarbons extracted from parasite, host and non-host eggs were similar. Eggs of V. dybowskii may survive in part due to being chemically transparent, as methyl-branched compounds only represent a tiny proportion (<1%) of the parasites hydrocarbon profile but a large proportion (26–41%) in both host species. However, the functions of various hydrocarbon groups need to be investigated in the hornets before this new acceptance mechanism of parasite eggs and adults is understood.     

The sodium cycle. I. Na-dependent motility and modes of membrane energization in the marine alkalotolerant Vibrio alginolyticus

Respiration, membrane potential generation and motility of the marine alkalotolerant Vibrio alginolyticus were studied. Subbacterial vesicles competent in NADH oxidation and Δψ generation were obtained. The rate of NADH oxidation by the vesicles was stimulated by Na⁺ in a fashion specifically sensitive to submicromolar HQNO (2-heptyl-4-hydroxyquinoline N-oxide) concentrations. The same amounts of HQNO completely suppressed the Δψ generation. Δψ was also inhibited by cyanide, gramicidin D and by CCCP + monensin. CCCP (carbonyl cyanide m-chlorophenylhydrazone) added without monensin exerted a much weaker effect on Δψ. Na⁺ was required to couple NADH oxidation with Δψ generation. These findings are in agreement with the data of Tokuda and Unemoto on Na⁺-motive NADH oxidase in V. alginolyticus. Motility of V. alginolyticus cells was shown to be (i) Na⁺-dependent, (ii) sensitive to CCCP + monensin combination, whereas CCCP and monensin, added separately, failed to paralyze the cells, (iii) sensitive to combined treatment by HQNO, cyanide or anaerobiosis and arsenate, whereas inhibition of respiration without arsenate resulted only in a partial suppression of motility. Artificially imposed ΔpNa, i.e., addition of NaCl to the K⁺-loaded cells paralyzed by HQNO + arsenate, was shown to initiate motility which persisted for several minutes. Monensin completely abolished the NaCl effect. Under the same conditions, respiration-supported motility was only slightly lowered by monensin. The artificially-imposed ΔpH, i.e., acidification of the medium from pH 8.6 to 6.5 failed to activate motility. It is concluded that Δ _Na⁺ produced by (i) the respiratory chain and (ii) an arsenate-sensitive anaerobic mechanism (presumably by glycolysis + Na⁺ ATPase) can be consumed by an Na⁺-motor responsible for motility of V. alginolyticus.     

山葡萄种质资源DNA条形码通用序列的筛选

对山葡萄(Vitis amurensis)种质资源样品的ITS、ITS2、psb A-trn H、rbc L和mat K序列进行PCR扩增及测序,优化PCR反应的退火温度,比较各序列的扩增效率、测序成功率、品种间和品种内的差异及barcoding gap图,使用BLAST和NJ树法比较不同序列的鉴定能力,最终从5条DNA片段中筛选出可用于山葡萄种质资源鉴定的DNA条形码通用序列。结果表明,在采集的11份33个山葡萄样品中,psb A-trn H和ITS2序列的扩增与测序成功率较高,其品种间、品种内差异及barcoding gap较ITS、rbc L和mat K序列具有明显的优势,且ITS2序列能够鉴别psb A-trn H序列无法鉴别的品种。实验证明,ITS2和psb A-trn H序列是较适合鉴别山葡萄资源的DNA条形码序列组合。DNA条形码弥补了形态学鉴定的不足,可为山葡萄种质资源的准确鉴定提供科学依据。     

Isoenzyme diversity and phylogenetic relationships among the American beans of the genus Vigna Savi (Fabaceae)

Electrophoretic variation of 13 isoenzyme systems encoded by 25 gene loci has been studied among the 12 American bean species of the genus Vigna, subgenera Sigmoidotropis and Lasiospron, in comparison with the two pantropical species Vigna luteola and V. vexillata of the subgenera Vigna and Plectrotropis, respectively. Of the 202 electromorphs (putative allozymes) discovered, 106 were phylogenetically informative, i.e. shared by at least two taxa, and 96 were taxon-specific. Parsimony, neighbour-joining and UPGMA analyses of the isozyme data as unordered presence–absence characters revealed the division of the American Vigna species into six clades which mostly correspond to the grouping of species into subgenera and sections in the traditional morphology-based systems, except in the placement of species V. gentryi and V. caracalla. The type species of the section Caracallae, V. caracalla, appears on the cladogram as basally paraphyletic in the subgenus Sigmoidotropis, but apart from the V. linearis group of the same section which forms a separate subclade. Vigna gentryi is not linked to other species of the section Sigmoidotropis, but appears in a distant subclade as a sister species to V. adenantha s. l. of the section Leptospron. The subgenus Lasiospron is sister to the pantropical V. vexillata of the African subgenus Plectrotropis.     

Effects of nutrients on germination of Verticillium lecanii (=Lecanicillium sp.) conidia and infection of greenhouse whitefly, (Trialeurodes vaporariorum)

Laboratory experiments were conducted to assess effects of nutrients on germination of Verticillium lecanii (=Lecanicillium sp.) conidia and infection of the greenhouse whitefly, Trialeurodes vaporariorum. Suspensions of V. lecanii conidia were prepared in four nutrient solutions: 2% glucose, 2% sucrose, 2% maltose, and 2% peptone. Suspensions in de-mineralized water served as the control. At 23°C the germination rate was highest in the 2% glucose solution, followed by sucrose, maltose, demineralized water, and peptone, respectively. Germ tube growth was greatest at 23°C in the 2% glucose solution after 10 h incubation. Results of the bioassays indicated that the nutrients influenced whitefly infection. Infection levels were highest for conidial suspensions (1×10⁶ conidia/mL) prepared in 2% glucose, and were significantly greater than for peptone, demineralized water and maltose. Infection levels at 1×10⁸ conidia/mL were not significantly different from each other for all materials tested. The potential use of nutrients in a spray formulation as a means of enhancing field efficacy are discussed.     

风车草和香根草在人工湿地中迁移养分能力的比较研究

为研究风车草(Cyperus alternifolius)和香根草(Vetiveria zizanioides)迁移养分的能力,建立17.0m²风车草潜流式人工湿地和13.3 m²香根草潜流式人工湿地处理猪场废水,在四个季节末测定植物生物量和组织氮、磷、铜、锌含量.结果表明,香根草地下部生物量大于风车草,地上部生物量则是风车草大于香根草.风车草年地上部收获量为3406.47 g·m^-2,比香根草的1483.88 g·m^-2高2.3倍;风车草的氮含量为22.69 mg·g^-1,比香根草的15.44 mg·g^-1高7.25 mg·g^-1;风车草的磷含量为6.09 mg·g^-1,比香根草的5.47 mg·g^-1高0.62 mg·g^-1.植株含铜、锌量风车草略比香根草高.风车草每年迁移N 68.72 g·m^-2和P18.49 g·m^-2,香根草迁移N 8.93 g·m^-2和P 3.69 g·m^-2.风车草人工湿地每年由植物迁移的氮、磷、铜、锌比香根草高4～7倍.     

西宁市萝卜黑心病的病原

萝卜黑心病是近年来在青海省西宁地区发生的一种新病害,重病田发病率高达100%,严重影响了萝卜的产量和品质。罹病萝卜肉质根的根尖及毛根颜色变暗,纵向剖开病根,可见肉质根的中柱组织自根尖向上呈不同程度的黑色;横向剖开病根,可见肉质根的中柱组织呈现均匀或不均匀放射状分布的黑色变色点。经病原菌分离培养、科赫氏法则证病,及病原菌形态学和分子生物学鉴定,明确该病的致病菌包括长孢轮枝菌Verticillium longisporum、三体轮枝菌V. tricorpus和瓜小织球壳菌Plectosphaerella cucumerina,其中长孢轮枝菌的组织侵染率达100%,为优势病菌。这3种病菌的适宜生长温度分别为20℃、20-25℃和25℃。本文是这3种病菌为害萝卜的首次报道,萝卜是这3种病菌的新寄主植物。     

信息素介导的西方蜜蜂与狄斯瓦螨互作研究进展

狄斯瓦螨是一种严重危害西方蜜蜂的体外寄生螨,是世界养蜂业的最大威胁.人们广泛采用化学方法防治狄斯瓦螨,但易引起狄斯瓦螨的抗药性、蜜蜂中毒和蜂产品药物残留等问题.为此,人们尝试了多种蜂螨绿色防控技术.其中利用蜜蜂信息素防治狄斯瓦螨是一个重要的研究方向.研究表明,狄斯瓦螨能利用蜜蜂信息素识别处于不同发育阶段的寄主,并对特定时期的寄主表现出高度的选择性.近年来,多种能作用于狄斯瓦螨的蜜蜂信息素相继被报道.这些信息素包括成蜂、蛹和幼虫信息素.有的信息素对狄斯瓦螨表现出驱避作用,有的则表现出引诱作用.本文对这些信息素的种类、主要组成成分、对狄斯瓦螨的作用等进行了综述,旨在为今后的研究与应用提供参考.     

Oligosaccharides in Five Different Vicia faba L. Cultivars

The oligosaccharide composition in seeds of some bean cultivars (two of Vicia faba L. and three of V. faba minor) have been examined. The sugars were isolated by solvent extraction and the concentrated extracts were analysed by PC and HPLC analyses. Characterization was also performed by thin-layer chromatography, enzymatic hydrolysis assays, GC determination of alditol acetate derivatives obtained after complete acid hydrolysis and FAB-MS of individual sucrose - galactosides. Although sucrose, raffinose, stachyose and verbascose were always identified, great differences in the total sugar content were found among the five cultivars. Sucrose and verbascose were the major components. Their contents were highest in the Muchamiel cv. (2.30 and 3.05 g/100g of dry bean, respectively). The selection of cultivars is the best way to improve the V. faba quality     

浙江镜湖湿地3种菌根植物根部真菌群落多样性及对金属元素富集能力的研究

城市湿地（urban wetland）植物多样性水平高,并具有积极的净化和美化环境的作用。本研究以浙江绍兴镜湖城市湿地公园为研究样地,通过ICP-AES检测了人工园区和次生林土壤中几种金属元素（Al、Cr、Cu、K和Zn）的含量,比较不同类型的菌根植物——黑麦草（Lolium perenne L.）（AM）、六月霜（Monochasma sauatieri Franch）（AM）和乌饭树（Vaccinium bracteatum Thunb）（ERM）对金属元素的富集作用。通过高通量测序分析各宿主植物根部真菌群落的组成和结构,比较其对宿主植物金属富集能力的影响。结果表明：（1）人工园区土壤中5种金属元素的含量均显著高于次生林下的土壤;（2）乌饭树对Al的富集能力较强,黑麦草和六月霜富集Cr能力都较强;（3）3种植物根部真菌主要来自Ascomycota,而乌饭树根部Basidiomycota也是优势真菌,AM真菌在黑麦草和六月霜根部真菌群落结构中较少,而公认的ERM真菌Helotiales和Sebacinales在乌饭树根部真菌群落中的比例较高,且与所测金属元素无显著相关性。绍兴镜湖城市湿地公园次生林土壤环境保持良好。     

Comparison of the physiological responses of Phaseolus vulgaris and Vigna unguiculata cultivars when submitted to drought conditions

Three cultivars differing in their susceptibility to water stress were compared—Phaseolus vulgaris cv. Carioca (susceptible), Vigna unguiculata cv. IT83D (intermediately tolerant) and V. unguiculata cv. EPACE-1 (tolerant)—during an imposed water stress treatment. Variation in leaf gas exchange (i.e. assimilation and stomatal conductance) and leaf relative water content in response to progressive substrate water depletion were investigated. To verify the extent of the injury caused by the drought treatment, leaf gas exchange was measured after rehydration. In the three cultivars, stomatal conductance declined before leaf relative water content was affected. P. vulgaris showed the largest decrease in the rate of stomatal conductance with decreasing substrate water content compared to both V. unguiculata cultivars. Photosynthetic assimilation rates were largely dependent on stomatal aperture, but there was evidence of the participation of non-stomatal factors in the reduction of CO₂ fixation. The response of leaf gas exchange parameters to severe water stress conditions differed significantly between P. vulgaris and V. unguiculata cultivars. After rehydration, cultivars can be characterised according to the degree of injury induced by the drought treatment: V. unguiculata cv. EPACE-1 as the least affected, V. unguiculata cv. IT83D slightly affected and P. vulgaris cv. Carioca strongly affected. Similar ranking was obtained with experiments previously performed at a cellular and subcellular level. Our results confirm the utility of physiological parameters as early screening tools for drought resistance in bean cultivars.     

Sphingolipid synthesis inhibitor fumonisin B1 causes verticillium wilt in cotton

Verticillium wilt caused by Verticillium dahliae is a major disease of cotton. Acidic protein–lipopolysaccharide complexes are thought to be the toxins responsible for its symptoms. Here, we determined that the sphingolipid biosynthesis inhibitor fumonisin B1 (FB1) acts as a toxin and phenocopies the symptoms induced by V. dahliae. Knocking out genes required for FB1 biosynthesis reduced V. dahliae pathogenicity. Moreover, we showed that overexpression of a FB1 and V. dahliae both downregulated gene, GhIQD10, enhanced verticillium wilt resistance by promoting the expression of brassinosteroid and anti-pathogen genes. Our results provide a new strategy for preventing verticillium wilt in cotton.