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Taccarum ulei (Araceae, Spathicarpeae) is a seasonal geophytic aroid, native to north‐eastern Brazil, that flowers during two months of the rainy season. Patterns of floral thermogenesis, pollination biology, and floral traits associated with pollination syndromes were studied and compared with those of other Araceae. Two species of cyclocephaline scarabs (Scarabaeidae, Cyclocephalini) were recognized as effective pollinators: Cyclocephala celata and Cyclocephala cearae. Larvae of an unidentified species of fruit fly (Melanoloma spp., Richardiidae, Diptera) were also frequently observed in inflorescences at various maturation stages, feeding on the connectives of male florets and fruits, and thus lowering the reproductive success of individual plants. Beetles were attracted by odoriferous inflorescences in the early evening of the first day of anthesis, during the female phase. The emission of attractive volatiles was coupled with intense thermogenic activity in the entire spadix, unlike other aroids in which only certain zones of the spadix heat up. Pollen release, which marks the beginning of the male phase on the subsequent evening, was not related to floral thermogenesis. Comparative multivariate analysis of the floral traits of T. ulei points to a beetle‐pollinated aroid, although some of the observed traits of the species are not common to other taxa sharing this pollination strategy. Such incongruence might be explained by the evolutionary history of the tribe Spathicarpeae and potential pollinator shifts. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, ••, ••–••.

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The identification of MPs as potent kairomones could prove instrumental in integrated pest management plans for these insects in emerging oil-yielding crops in South America, including those of the wine palm (Att. butyracea) and macaw palms (Acrocomia spp.). © 2018 Society of Chemical Industry.

Bacterial infections directly affect the world's population, and this situation has been aggravated by indiscriminate use of antimicrobial agents, which can generate resistant microorganisms. In this report, an initial screening of proteins with antibacterial activity from corms of 15 species of the Xanthosoma genus was conducted. Since Xanthosoma blandum corms showed enhanced activity toward bacteria, a novel protein with bactericidal activity was isolated from this particular species. Edman degradation was used for protein N-termini determination; the primary structure showed similarities with Kunitz inhibitors, and this protein was named Xb-KTI. This protein was further challenged against serine proteinases from different sources, showing clear inhibitory activities. Otherwise, no hemolytic activity was observed for Xb-KTI. The results demonstrate the biotechnological potential of Xb-KTI, the first proteinase inhibitor with antimicrobial activity described in the Xanthosoma genus.

Nocturnal flowering plants often release strong scents to attract their pollinators. Among night active flower visitors are cyclocephaline scarab beetles, which have been demonstrated to respond to uncommon volatile organic compounds released in high amounts by their host plants. In Araceae, the molecular structure of several such compounds is yet to be unveiled. We investigated headspace floral scent samples of Philodendron squamiferum, Thaumatophyllum mello-baretoanum, and Xanthosoma hylaeae by a variety of approaches, leading to the identification of novel compounds. Dehydrojasmone, (Z)-4-methylene-5-(pent-2-en-1-yl)cyclopent-2-en-1-one (1), (Z)-3-methylene-2-(pent-2-en-1-yl)cyclopentyl acetate (isojasmyl acetate, 3), and (E)-4,8-dimethylnona-1,3,7-trien-5-yl acetate (4) had not been previously reported, while full analytical data of the recently described (Z)-3-methylene-2-(pent-2-en-1-yl)cyclopentan-1-ol (isojasmol, 2) are presented here. All these compounds are derived from more common precursors, (Z)-jasmone and (E)-4,8-dimethyl-1,3,7-nonatriene, likely through biosynthetic "post-processing".

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RESUMO -(Descrição do padrão de venação foliar em Spathicarpa Hook. (Araceae)). O estudo e a caracterização da venação foliar representam uma possibilidade de auxílio no reconhecimento de grupos taxonômicos identificados, predominantemente, com base em caracteres reprodutivos como o gênero Spathicarpa Hook. (Araceae). O presente estudo teve como objetivos: apresentar um método eficiente para diafanização de folhas similares às de Spathicarpa Hook.; descrever o padrão de venação das folhas de Spathicarpa gardneri Schott, Spathicarpa hastifolia Hook., Spathicarpa lanceolata Engl. e Spathicarpa sagittifolia Schott; e testar a utilização da arquitetura foliar de Spathicarpa Hook. como ferramenta taxonômica capaz de fornecer características diagnósticas vegetativas no gênero. Em linhas gerais, a técnica de diafanização consistiu inicialmente em submeter folhas frescas, estocadas em álcool etílico 70% com detergente comercial, ao hidróxido de sódio (5%) e hipoclorito de sódio (5%) para clareamento e alvejamento, respectivamente. Em seguida, estas passaram por uma bateria de desidratação etanólica crescente (10 a 100%) e por uma série com xileno (xileno-etanol 100% 1:1 e xileno). Foram então coradas com safranina e colocadas novamente em xileno-etanol 100% 1:1 para diferenciar. Das quatro espécies estudadas, somente Spathicarpa lanceolata Engl. apresenta características vegetativas diagnósticas, não sendo possível diferenciar, com base na arquitetura foliar, as demais espécies. Palavras-chave: Arquitetura foliar, Técnica de diafanização, lóbulosABSTRACT -(Description of leaf venation pattern in Spathicarpa Hook. (Araceae)). Characterization of leaf venation can help in the recognition of taxonomic groups that are identified primarily on the basis of reproductive characteristics such as genus Spathicarpa Hook. (Araceae). This study aims to provide an efficient technique for clearing leaves that are similar to those of Spathicarpa Hook., to describe the leaf venation pattern of Spathicarpa gardneri Schott, Spathicarpa hastifolia Hook., Spathicarpa lanceolata Engl. and Spathicarpa sagittifolia Schott, and to test the use of leaf architecture as a tool for taxonomic recognition of Spathicarpa Hook. species. In general, the leaf clearing technique initially involved placing leaves in 70% ethyl alcohol with commercial detergent, sodium hydroxide (5%) and sodium hypochloride for clearing and whitening, respectively. The leaves were then run through an ethanol dehydration series (10 to 100%) and through a xylene series (xylene-ethanol 100% 1:1 and xylene). Lastly, leaves were died with safranin and again placed in xylene-ethanol 100% 1:1 to differentiate. Of the four species, only Spathicarpa lanceolata Engl. presented diagnostic vegetative characteristics. It was not possible to distinguish amongst the other species based only on leaf architecture. Key words: leaf architecture, leaf-clearing technique, lobules IntroduçãoAs folhas são, tipicamente, estruturas simétricas bilateralmente achatadas, oriundas das células laterais d...