Contrasting mtDNA and microsatellite data of great reed warbler Acrocephalus arundinaceus breeding populations on a small geographic scale

The great reed warbler has two genetically distinguishable haplogroups: "Clade A" occurs in higher proportions in Western Europe and Kazakhstan, and colonised Europe and Asia from a refugium in South-West Europe; and "Clade B", which is more common in Eastern Europe, and colonised parts of Europe from a refugium in the Middle East. Our aims were (i) to analyse the rate of differentiation in Hungarian breeding populations in order to see whether European-scale pattern is visible or not on as a small scale as the territory of Hungary and (ii) to compare the results obtained with mtDNA sequencing and microsatellite markers. To analyse the genetic differentiation, the mtDNA control region II was sequenced in 68 adult breeding birds, and 51 were fingerprinted at 11 microsatellite loci, while both analyses were performed on 36 birds (a total of 83 birds). The microsatellite data gave a better resolution and represented the fine-scale pattern of the suspected recolonisation. The lack of genetic differentiation among the breeding populations based on mitochondrial data seems to support this finding, because the admixture of the clades in this particular geographic region obliterates differentiation. Accordingly, the F_st values from different branches are significantly based on microsatellite data only. The mtDNA methods only give reliable results when a geographic and ecological factor plays a role in the population subdivision, but in the case of an intermixing population larger-scale studies are needed.

Determination of polyphenols and in vitro antimicrobial and antioxidant activity of Calluna vulgaris (L.) Hull

Calluna vulgaris (L.) Hull belonging to Ericaceae family occurs mostly at sour habitats in subalpine regions in Europe. The species is cultivated in many countries, but it is known as medicinal plant because of polyphenols and aucubin as main compounds. In this work, the polyphenolic, flavonoid, and tannin content, as well as the antimicrobial and antioxidant activity of the aerial part, were evaluated. In phytochemical analyses, methanol extract showed the highest phenolic and flavonoid content, followed by ethanol, methanol/water, and aqueous extracts. In antimicrobial tests, chloroform, ethyl acetate, butanol, and water extracts inhibited the growth of S. aureus and MRSA, while butanol and water fractions were effective against E. coli, and water extract for E. coli ESBL and K. pneumoniae ESBL. Water extract showed the most inhibitory effect for the tested 2 g-positive and 3 g-negative strains including both bactericidal and bacteriostatic activity. Data analysed by Pearson coefficient correlation showed positive correlation between polyphenol and flavonoid content. The determined antioxidant capacity of the herb ranged from 0.145 to 0.296 mg/mL. The results highlight the significance of the plant as possible antioxidant source and as an antimicrobial agent for further studies.

The taxon-specific paralogs of grapevine PRLIP genes are highly induced upon powdery mildew infection

PRLIP (pathogenesis-related lipase) is a gene family encoding class 3 lipase-like proteins originally described and first characterized in Arabidopsis thaliana. Nine paralog genes of Arabidopsis can be separated into two groups based on expression characteristics and pathogen responses. Genes of Group 1 are clustered on chromosome 5 and show either high inducibility to different stress hormones and in response to pathogen attack or are undetectable at the transcript level. Group 2 contains the remaining genes, spread over the genome and are expressed constitutively in all the tissues tested. The aim of the present study was to determine the distribution of these two groups among plants, and to verify their differential expression. Orthologs of constitutively active members (Group 2) were found in all angiosperms, with available genome sequences. They are referred to as "core PRLIPs". In contrast, the gene cluster containing the pathogen-inducible PRLIPs (Group 1) was unique for Arabidopsis. Among other angiosperms, grapevine also possesses such a unique genome-specific group of PRLIP genes. To investigate whether these genes are also counterparts in pathogen responses, their expression pattern was tested under stress conditions. Two of the specific Vitis PRLIPs were highly induced in response to both powdery mildew infection and benzothiadiazole (BTH) treatment. Core Vitis PRLIPs, however, were not responsive to either pathogen attack or the chemical inducer. Our data provide insights into the distribution of a pathogenesis-related gene family in different plant lineages, and might reveal common characteristics with other inducible defense-related gene families.

The phylogenetic relationships among some Randia (Rubiaceae) taxa

Phylogenetic relationships among some Randia (Rubiaceae, Gardenieae) taxa were estimated based on sequence variation in the nuclear ribosomal internal transcribed spacers (ITS) and rps 16 intron (cpDNA). During the investigation of rpsl6 intron of 9 studied Central American Randia species, two well supported subclades were separated. Analysis of ITS data of 16 Randia species shows 3 major clades. A group of mainly lowland, South American Randia species is moderate supported (75%). Species from Mexico form a strongly supported (97%) clade, but the Central American and Mexican Randia species are low supported (58%). However the last two groups are well supported together (95%). The molecular delimination is well in line with the size of leaves combined with the texture of exocarp.