An approach to phenotypic analysis and environmental variability. The examples of the genera Dianthus L. and Lotus L. in the north of Portugal

The analysis of the correlation between phenotypic plasticity and environmental variability has been very useful to describe the morphologic responses of individuals to environmental factors affecting them (in the present contribution the altitudinal variation), from a genecological perpective. However, the literature shows that the studies in this area have had a monospecific or monogeneric use. As a consequence, intergeneric comparative descriptions have not been possible. In the present work we propose an analytical method to compare the morphological expressivity of individuals included in the genera Dianthus and Lotus from the north of Portugal by means of a contingency matrix. This matrix was elaborated on the basis of amplitude parameters, in order to describe the variability present in the basic matrix of each genus studied. The results pointed out the existence of opposite phenotypic behaviours dependent on the altitudinal variation, thus indicating the importance of the analysis between different groups of taxa as a reference for the comparison of their morphological expressivities

Morpho-environmental characterization of the genus Baldellia Parl. (Alismataceae) in the Iberian Peninsula, Balearic islands and North Morocco

The genus Baldellia Parl. has always been a complex taxon. Three species and three subspecies have been proposed for the Iberian Peninsula. The morphological variation of this genus in the Iberian Peninsula, Balearic islands and northern Morocco, and its thermo-pluviometric and altitudinal correlation are the focus of this contribution. Twenty-eight morphological variables were examined and subjected to a multivariate statistical analysis. The three morphotypes observed (Form 1, which includes B. ranunculoides subsp. repens and B. alpestris; Form 2, which includes B. ranunculoides and Form 3 for the new combination B. ranunculoides subsp. ranunculoides var. tangerina (Pau) J. Rocha, A. Crespi, M. Garcia-Barriuso, R. Almeida, J. Honrado, comb. nova proposed here for the first time) seem to represent different reproductive strategies. Morphological variables related with the presence or absence of stolons and the architecture of the inflorescence; the size and number of fruits are the most discriminating variables. Form 1 represents the asexual morphotype; Forms 2 and 3 correspond to morphotypes for which sexual reproduction is preferential. The environmental approach revealed that the asexual form (Form 1) grows in temperate, in more humid conditions, and within a broad altitudinal range. In contrast, the two sexual forms are more common in warmer and drier conditions, and occur over a narrower interval of altitudes

Candida albicans Scavenges Host Zinc via Pra1 during Endothelial Invasion

The ability of pathogenic microorganisms to assimilate essential nutrients from their hosts is critical for pathogenesis. Here we report endothelial zinc sequestration by the major human fungal pathogen, Candida albicans. We hypothesised that, analogous to siderophore-mediated iron acquisition, C. albicans utilises an extracellular zinc scavenger for acquiring this essential metal. We postulated that such a “zincophore” system would consist of a secreted factor with zinc-binding properties, which can specifically reassociate with the fungal cell surface. In silico analysis of the C. albicans secretome for proteins with zinc binding motifs identified the pH-regulated antigen 1 (Pra1). Three-dimensional modelling of Pra1 indicated the presence of at least two zinc coordination sites. Indeed, recombinantly expressed Pra1 exhibited zinc binding properties in vitro. Deletion of PRA1 in C. albicans prevented fungal sequestration and utilisation of host zinc, and specifically blocked host cell damage in the absence of exogenous zinc. Phylogenetic analysis revealed that PRA1 arose in an ancient fungal lineage and developed synteny with ZRT1 (encoding a zinc transporter) before divergence of the Ascomycota and Basidiomycota. Structural modelling indicated physical interaction between Pra1 and Zrt1 and we confirmed this experimentally by demonstrating that Zrt1 was essential for binding of soluble Pra1 to the cell surface of C. albicans. Therefore, we have identified a novel metal acquisition system consisting of a secreted zinc scavenger (“zincophore”), which reassociates with the fungal cell. Furthermore, functional similarities with phylogenetically unrelated prokaryotic systems indicate that syntenic zinc acquisition loci have been independently selected during evolution

Cytotaxonomic study of some taxa of the subtribe Orchidinae (Orchidoideae, Orchidaceae) from the Iberian Peninsula

Chromosome numbers in 29 populations belonging to 21 species of Orchidinae from the Iberian Peninsula have been counted. For four Iberian endemic species, Anacamptis coriophora subsp. carpetana, Dactylorhiza caramulensis, Orchis tenera, and Serapias perez-chiscanoi, the number of chromosomes is reported here for the first time. For another three, Anacamptis champagneuxii, Himantoglossum hircinum, and Orchis langei, this number has been established in Iberian representatives. Moreover, new ploidy levels have been obtained for Anacamptis champagneuxii and Dactylorhiza sambucina. Some taxonomic, phylogenetic, and phytogeographic comments are made for several species or groups of species from the Western Mediterranean region

Micromorphological study of some taxa of the genus Epipactis (Orchidaceae) from the Central-Western Iberian Peninsula

Micromorphological information on Iberian Epipactis species is very limited. Using scanning electron microscopy, we examined the differences in leaf border denticulation and rachis, as well as floral pedicel hairs in six populations of Epipactis (E. helleborine, E. lusitanica and E. tremolsii) from the Central-Western Iberian Peninsula. These taxa showed important differences in these characteristics, some of which seem to correspond to the different habitats occupied. Some taxonomic and phytosociological comments are made on these species

A new endemic species of Epipactis (Orchidaceae) from north-east Portugal

A new species, Epipactis duriensis Bernardos, D. Tyteca, Revuelta & Amich is described and illustrated from north-east Portugal. Notes on its distribution, ecology, karyology, micromorphology and taxonomic relationships are presented as well as molecular data based on ITS analysis. A list of diagnostic differences between E. duriensis and the closely related species E. lusitanica and E. tremolsii is provided. © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society, 2004, 145, 239–249