Evolution of genome space occupation in ferns: linking genome diversity and species richness.

Background And Aims: The dynamics of genome evolution caused by whole genome duplications and other processes are hypothesized to shape the diversification of plants and thus contribute to the astonishing variation in species richness among the main lineages of land plants. Ferns, the second most species-rich lineage of land plants, are highly suitable to test this hypothesis because of several unique features that distinguish fern genomes from those of seed plants. In this study, we tested the hypothesis that genome diversity and disparity shape fern species diversity by recording several parameters related to genome size and chromosome number.

Historical biogeography of the fern genus Polystichum (Dryopteridaceae) in Austral South America.

A group of seven endemic Polystichum species inhabit Patagonia, the southern region of South America. To date, evolutionary relationships of these Austral South American Polystichum remain unknown. The biota of the Southern Andes appears to be more closely related to the temperate Australasian species than to northern South American ones.

Typifications and synonymy in Polystichum (Dryopteridaceae) from Chile and Argentina.

Polystichum Roth is one of the largest and most taxonomically challenging fern genera. South American species have a rich and complex nomenclatural history; many of the early names are inadequately typified. Based on extensive examination of original type material, we designate eleven lectotypes (including Aspidium mohrioides, Aspidium montevidense f.

Cholesterol induces surface localization of polyphenols in model membranes thus enhancing vesicle stability against lysozyme, but reduces protection of distant double bonds from reactive-oxygen species.

The main scope of the present study was to analyze the membrane interaction of members of different classes of polyphenols, i.e. resveratrol, naringenin, epigallocatechin gallate and enterodiol, in model systems of different compositions and phase states.

The antimicrobial peptide microcin J25 stabilizes the gel phase of bacterial model membranes.

The bacterial membrane interaction of the antimicrobial peptide microcin J25 was studied with the probe-free techniques Langmuir monolayers and infrared spectroscopy. Membrane model systems composed by phosphatidylethanolamine:phosphatidylglycerol 7:3, which mimic the cytoplasmic membrane of Gram negative bacteria, were used in both monolayer and bilayer approaches. The peptide reduced the transition surface pressure of the expanded-to-condensed lipid monolayer states, as well as increased the gel-to-liquid crystalline transition temperature in bilayers, indicating a stabilization of membrane ordered state.