Development of the cuticular wax during growth of Kalanchoe daigremontiana (Hamet et Perr. de la Bathie) leaves

The goal of the present study was to monitor cuticular wax accumulation during leaf development of Kalanchoe daigremontiana . Leaves expanded linearly until they were 40–60 d old. Wax coverages of leaves on the third node increased steadily during initial leaf development, from 6.5  µ g·cm⁻² on day 22 to 15.3  µ g·cm⁻² on day 53, and then levelled off. Triterpenoids dominated the wax mixture throughout leaf development, but decreased from 74 to 40–45% in mature leaves, while very long-chain fatty acid (VLCFA) derivatives increased from 19 to 39–44%. The major VLCFA derivatives were alkanes, accompanied by fatty acids, primary alcohols, aldehydes and alkyl esters. In all compound classes, either C₃₄ or C₃₃ homologs predominated during leaf development. Eight different triterpenoids were identified, with glutinol constituting 70% of the fraction, and friedelin (20%) and germanicol (10%) as further major components of the young leaf wax. The glutinol percentage decreased, while the relative amounts of epifriedelanol and glutanol increased during development. Various leaf pairs upwards from the third node showed similar growth patterns and developmental time courses of cuticular wax amounts and composition. Based on these surface chemical analyses, the relative activities of biosynthetic pathways leading to various wax components can be assessed.     

Composition of epicuticular wax layer of two species of Mandevilla (Apocynoideae,Apocynaceae) from Rio de Janeiro,Brazil

The chemical composition of epicuticular waxes of Mandevilla guanabarica and Mandevilla moricandiana was comparatively analyzed by extraction in n-hexane and chloroform. The mean wax content per unit of leaf area in the n-hexane extract was about 13–30 μg cm⁻² for M. guanabarica, containing 20–28% n-alkanes and 55–63% triterpenes; for M. mori-candiana, the mean content was 19 μg cm⁻², containing 73% n-alkanes and 14% triterpenes. In the chloroform extract, the wax yield was 40–80 μg cm⁻² for M. guanabarica, with about 9–11% n-alkanes and 75–82% triterpenes; while for M. moricandiana, the wax yield was 110 μg cm⁻², with 52% n-alkanes and 14% triterpenes. The major compounds identified were lupeol, pentacyclic triterpenes of the α- and β-amyrin class, and n-alkanes such as nonacosane, hentriacontane and tritriacontane. These results indicate that the quantitative chemical profiles of epicuticular waxes of M. guanabarica and M. moricandiana are distinct and could be used as an additional feature in taxonomic identification.     

核盘菌侵染对拟南芥表皮蜡质结构及化学组成的影响

以野生型拟南芥与蜡质突变体cer1、cer4为试验材料,通过研究核盘菌胁迫对拟南芥茎表皮蜡质结构及组分含量的影响,揭示核盘菌侵染与表皮蜡质的关系。扫描电镜结果显示,野生型拟南芥蜡质晶体以垂直于表面的杆状、块状结构为主;突变体cer1晶体类型以水平的松针状、块状结构为主;突变体cer4蜡质晶体以垂直片层结构为主。核盘菌胁迫下,拟南芥蜡质晶体结构及分布形态发生变化。蜡质层结构在核盘菌胁迫下表现为:杆状、松针状蜡质晶体减少—蜡质晶体熔融—表皮"囊状凸起"—表皮膜层破裂。这些结构变化有利于病菌突破角质层屏障而侵入到植株体内。色质谱分析结果显示:与野生型相比,cer1突变体烷、次级醇、酮类显著减少;cer4突变体表现为一级醇含量减少。接种核盘菌后,野生型拟南芥与蜡质突变体一级醇类显著增加(cer1增加不显著);烷类、次级醇类、酮类含量与蜡质总量均显著减少,表明蜡质前体物质在受到核盘菌胁迫后更多地通过酰基还原途径生成一级醇,从而减少了由脱羰基途径所生成的蜡质组分。核盘菌通过改变表皮蜡质晶体结构与化学组分分泌量来促进侵染。     

Very long chain alkylresorcinols accumulate in the intracuticular wax of rye (Secale cereale L.) leaves near the tissue surface

Alkylresorcinols (ARs) are bioactive compounds occurring in many members of the Poaceae, likely at or near the surface of various organs. Here, we investigated AR localization within the cuticular wax layers of rye (Secale cereale) leaves. The total wax mixture from both sides of the leaves was found to contain primary alcohols (71%), alkyl esters (11%), aldehydes (5%), and small amounts (<3%) of alkanes, steroids, secondary alcohols, fatty acids and unknowns. A homologous series of ARs (3%) was identified by GC-MS and comparison with a synthetic standard of nonadecylresorcinol. The alkyl side chains of the wax ARs contained odd numbers of carbons ranging from C19 to C27, with a prevalence of C21, C23 and C25. Waxes from both sides of the leaf, analyzed separately in a second experiment, comprised the same compound classes in similar relative amounts and with similar homolog patterns. Finally, the epicuticular and intracuticular wax layers were sampled separately from the abaxial side of the leaf. While ARs accounted for 2% of the intracuticular wax, they were not detectable in the epicuticular wax. The intracuticular wax was also slightly enriched in steroids, whereas the epicuticular layer contained more primary alcohols. All other wax constituents were distributed evenly between both wax layers.     

Septal pore complex morphology in the Agaricomycotina (Basidiomycota) with emphasis on the Cantharellales and Hymenochaetales

The ultrastructure of septa and septum-associated septal pore caps are important taxonomic markers in the Agaricomycotina (Basidiomycota, Fungi). The septal pore caps covering the typical basidiomycetous dolipore septum are divided into three main phenotypically recognized morphotypes: vesicular-tubular (including the vesicular, sacculate, tubular, ampulliform, and globular morphotypes), imperforate, and perforate. Until recently, the septal pore cap-type reflected the higher-order relationships within the Agaricomycotina. However, the new classification of Fungi resulted in many changes including revision of existing and addition of new orders. Therefore, the septal pore cap ultrastructure of more than 325 species as reported in literature was related to this new classification. In addition, the septal pore cap ultrastructures of Rickenella fibula and Cantharellus formosus were examined by transmission electron microscopy. Both fungi have dolipore septa associated with perforate septal pore caps. These results combined with data from the literature show that the septal pore cap-type within orders of the Agaricomycotina is generally monomorphic, except for the Cantharellales and Hymenochaetales.It appears from the fungal phylogeny combined with the septal pore cap ultrastructure that the vesicular-tubular and the imperforate type both may have arisen from endoplasmic reticulum. Thereafter, the imperforate type eventually gave rise to the perforate septal pore cap-type.     

Diversimorbus metrosiderotis gen. et sp. nov. and three new species of Holocryphia (Cryphonectriaceae) associated with cankers on native Metrosideros angustifolia trees in South Africa

The Cryphonectriaceae includes important tree pathogens, especially on the Myrtales. During a routine disease survey in the Western Cape Province of South Africa, a fungus resembling the Eucalyptus pathogen Holocryphia eucalypti was observed on native Metrosideros angustifolia (Myrtales). The aims of this study were to identify the fungus and to expand surveys for fungi in the Cryphonectriaceae on M. angustifolia. Fungi were identified based on DNA sequence comparisons and morphological features, and their pathogenicity was tested on M. angustifolia under field conditions. Based on morphology and multigene phylogenetic analyses of DNA sequence data from six gene regions, we describe a new genus including a single species and three new species of Holocryphia (Cryphonectriaceae) from M. angustifolia. These fungi are provided with the names Diversimorbus metrosiderotis gen. et sp. nov., Holocryphia capensis sp. nov., Holocryphia gleniana sp. nov., and Holocryphia mzansi sp. nov. We also revise H. eucalypti, the type of the genus, to include only isolates from Eucalyptus in South Africa. Research results indicated that H. mzansi may undergo host shifts between different tree genera in the Myrtaceae. Inoculation tests showed that isolates of all the newly described species can cause lesions on the branches of M. angustifolia, indicating that they are all pathogens of this tree.     

野丁香属植物叶表皮形态特征研究

在光学显微镜和电子扫描显微镜下观察了茜草科(Rubiaceae)野丁香属(Leptodermis Wall.) 35种8变种植物的叶表皮微形态特征.结果表明,野丁香属植物叶表皮细胞为多边形或不规则形状,垂周壁平直、弓状或波状.气孔器全部位于下表皮,有辐射型、平列型两种,其中平列型较为普遍.表皮毛在上下表皮都有分布,有单...     

Systematics and evolution of the genus Torrubiella (Hypocreales, Ascomycota)

Torrubiella is a genus of arthropod-pathogenic fungi that primarily attacks spiders and scale insects. Based on the morphology of the perithecia, asci, and ascospores, it is classified in Clavicipitaceae s. lat. (Hypocreales), and is considered a close relative of Cordyceps s. 1., which was recently reclassified into three families (Clavicipitaceae s. str., Cordycipitaceae, Ophiocordycipitaceae) and four genera (Cordyceps s. str, Elaphocordyceps, Metacordyceps, and Ophiocordyceps). Torrubiella is distinguished morphologically from Cordyceps s. lat. mainly by the production of superficial perithecia and the absence of a well-developed stipitate stroma. To test and refine evolutionary hypotheses regarding the placement of Torrubiella and its relationship to Cordyceps s. lat., a multi-gene phylogeny was constructed by conducting ML and Bayesian analyses. The monophyly of Torrubiella was rejected by these analyses with species of the genus present in Clavicipitaceae, Cordycipitaceae, and Ophiocordycipitaceae, and often intermixed among species of Cordyceps s. lat. The morphological characters traditionally used to define the genus are, therefore, not phylogenetically informative, with the stipitate stromata being gained and/or lost several times among clavicipitaceous fungi. Two new genera (Conoideocrella, Orbiocrella) are proposed to accommodate two separate lineages of torrubielloid fungi in the Clavicipitaceae s. str. In addition, one species is reclassified in Cordyceps s. str. and three are reclassified in Ophiocordyceps. The phylogenetic importance of anamorphic genera, host affiliation, and stipitate stromata is discussed.     

Reclassification of Aeromonas hydrophila subsp. dhakensis Huys et al. 2002 and Aeromonas aquariorum Martínez-Murcia et al. 2008 as Aeromonas dhakensis sp. nov. comb nov. and emendation of the species Aeromonas hydrophila

Previous studies indicate that Aeromonas aquariorum and Aeromonas hydrophila subsp. dhakensis are the same taxon and suggest that they should be synonymized. Using a polyphasic approach, the phenotypic and phylogenetic relationship of A. aquariorum with the 3 defined A. hydrophila subspecies (i.e. dhakensis, hydrophila, ranae) was investigated. Phylogenetic trees derived from the 16S rRNA, rpoD or gyrB genes and a multilocus phylogenetic analysis (with the concatenated sequences of gyrB, rpoD, recA, dnaJ and gyrA) confirmed that both A. aquariorum and A. hydrophila subsp. dhakensis are a unique taxon, different from the other A. hydrophila subspecies, corroborating the phenotypic and DNA–DNA hybridization (DDH) results. A formal synonymization of A. aquariorum and A. hydrophila subsp. dhakensis and a reclassification of both as Aeromonas dhakensis sp. nov. comb nov. is therefore proposed.     

Diaceratherium massiliae nov. sp. des argiles oligocènes de Saint-André et Saint-Henri à Marseille et de Les Milles près d’Aix-en-Provence (SE de la France), premier grand Rhinocerotidae brachypode européen

A revision of all previously collected mammalian fossils from the two Late Oligocene sites of Saint-André and Saint-Henri in Marseille (both from the MP 26 reference-level) allows us to identify three Rhinocerotoidea species: Protaceratherium albigense, Ronzotherium romani, Diaceratherium massiliae nov. sp., and maybe a fourth one, Eggysodon cf. gaudryi. Only the first two were previously known there. D. massiliae nov. sp. is found together with R. romani; it is the first case of sympatry ever known between the two genera. D. massiliae nov. sp. is then the most ancient Diaceratherium in Europe, where the genus was previously unknown before the MP 29 reference-level. It is a very large species whose limb bones proportions foreshadow these of the later species of the genus, especially D. lemanense from the Late Oligocene-Early Miocene. This suggests a possible phylogenetic link between D. massiliae nov. sp. and D. lemanense, and the coexistence of at least two different but partially contemporaneous lineages among the European Diaceratherium. In Les Milles near Aix-en-Provence, also from the MP 26 reference-level, the three species P. albigense, R. romani and D. massiliae nov. sp. were also found.     

The ethnobotany and pharmacognosy of Olea europaea subsp. africana (Oleaceae)

The ethnobotanical uses of wild olive, O. europaea subsp. africana (sometimes referred to as subsp. cuspidata) in southern Africa and in other parts of Africa are reviewed. Chromatographic analyses of secoiridoids (oleuropein and other oleuropeosides) in 25 wild olive leaf samples from 10 localities in South Africa showed substantial amounts of oleuropein (up to 110 mg/g dry weight) and not trace amounts as reported in the literature. Oleuropein is the main active compound in olive leaf, with demonstrated anti-oxidant, anti-microbial, hypolipidemic and hypotensive activities. A comparison with nine cultivated olive leaf samples (subsp. europaea) from six cultivars and two localities showed that commercial olive leaf can be distinguished by the presence of verbascoside, which is absent in wild olive. Extraction methods and solvent systems (TLC and HPLC) were compared, using pure oleuropein (isolated from wild olive leaf and identified by NMR) as an authentic reference sample. The unique peltate scales on the leaves are useful to identify olive leaf raw material (but are the same in both subspecies). The main conclusion is that wild olive leaf is chemically closely similar to cultivated olive leaf and therefore suitable as an alternative source of raw material for olive leaf extract.     

Use of spent mushroom substrates from Agaricus subrufescens (syn. A. blazei, A. brasiliensis) and Lentinula edodes productions in the enrichment of a soil-based potting media for lettuce (Lactuca sativa) cultivation: Growth promotion and soil bioremediation

This study aimed to assess physicochemical and microbiological properties of fresh spent mushroom substrates (SMSs) – without post-crop heat treatment – from Agaricus subrufescens and Lentinula edodes production to optimize the use of these residues in the soil enrichment for lettuce growth promotion and soil remediation. Organic matter and C content of both SMSs were high. Fresh A. subrufescens SMS was a good source of N, P and K. On the other hand, L. edodes SMS presented a lower concentration of these nutrients and a high level of immaturity. Both SMSs presented high electric conductivity values (2.5–3.4 mS/cm). Microbiological analysis, based upon enumeration of culturable bacteria (thermophilic and mesophilic) and fungi, and also evolution of CO₂, showed that SMSs played higher microbial diversity than soil control. Laccase activity from A. subrufescens SMS tended to remain constant during a 2-month period, while L. edodes SMS presented low laccase activity throughout the same period. Agaricus subrufescens and L. edodes were able to grow on a PDA (Potato Dextrose Agar) media supplemented with different concentrations of atrazine (1–50 μg/ml), degraded the herbicide, attaining rates of 35% and 26%, respectively. On experiments of lettuce growth promotion using a soil-based potting media with different SMS rates, 5% and 10% (dw) rates of A. subrufescens SMS resulted in higher lettuce aerial dry weights than the rates of 25% and 40%, the chemical fertilization (NPK) and the control (soil). At 10% supplementation, lettuce aerial dry weight increased 2.2 and 1.3 times compared to the control and the NPK treatment, respectively. Protein content increased along with SMS rates. Fresh A. subrufescens SMS was an excellent supplement for lettuce growth promotion and showed potential for remediation of biocides possibly due to improved microbial diversity and enzymatic activity. Fresh L. edodes SMS was not a good fertilizer, at least under the conditions tested. However, microbiological analysis showed that promising results may be achieved when using fresh L. edodes SMS for soil remediation.     

Fate of resting cysts of Alexandrium spp. ingested by Perinereis nuntia (Polychaeta) and Theola fragilis (Mollusca)

The ingestion of resting cysts of Alexandrium spp. by Perinereis nuntia (Polychaeta) and Theola fragilis (Mollusca) was experimentally examined in the laboratory. P. nuntia and T. fragilis were cultured in bottom sediment containing a high density of Alexandrium cysts under dark conditions. Moreover, to evaluate the degree and consequence of being ingested, the density of cysts in the control sediment (no macrobenthic organisms) and the germination capability of the cysts in the faecal pellets of the two species of macrobenthos were examined.Cysts in the culture sediment were found to be ingested by both P. nuntia and T. fragilis. No difference in the density of cysts between the sediments cultured with and without P. nuntia was observed. However, the density of cysts in the sediments with T. fragilis decreased by 24% compared to the density in the control sediment. It is possible that most of the cysts ingested were digested by T. fragilis. The rate of Alexandrium cyst digestion by this species is estimated 594 cysts/individual/day. It is estimated that 91% of the cysts ingested by T. fragilis were partially or totally digested and only 9% were excreted in a viable state during the experiment. Thus, T. fragilis has a stronger affect on the abundance of Alexandrium cysts compared with P. nuntia.No significant difference was observed between the germination success of the cysts from faecal pellets of P. nuntia and T. fragilis compared to the cysts in the control sediment. If, however, the necessary light for the cysts to germinate is cut off by being enclosed within the faecal pellet, the germination rate of cysts from the faecal pellets may be suppressed.     

Pollen morphology of Chinese Curcuma L. and Boesenbergia Kuntz (Zingiberaceae): Taxonomic implications

In order to find new non-molecular evidence to support the phylogenetic and taxonomic position, pollen grains of 20 populations of 16 species of Chinese Curcuma L. and Boesenbergia Kuntz (Zingiberaceae) were investigated under SEM and TEM. The pollen grains are spherical and ovoid, nonaperturate. The pollen wall is composed of a very thin exine and a thick intine. The exine is psilate or echinate. The intine consists of two layers, i.e., a thick, channeled layer (exintine) and an inner homogenous layer (endintine). The results reveal morphological congruence between the pollen grains of species of Curcuma, which according to DNA sequence data appears to be a polyphyletic genus. However the uniform pollen morphology in Curcuma provides no evidence to divide this genus into separate taxonomic entities. Our results on pollen morphology also do not provide any additional evidence to either unite or segregate Boesenbergia albomaculata and Curcumorpha longiflora in the same genus and demonstrate that more taxonomic data on the genus Boesenbergia and its relatives are needed before a final decision can be made.