Range-constrained co-occurrence simulation reveals little niche partitioning among rock-dwelling land snails (Gastropoda: Clausiliidae).

Aim: Taxon co-occurrence analysis is commonly used in ecology, but it has not been applied to range-wide distribution data of partly allopatric taxa because existing methods cannot differentiate between distribution-related effects and taxon interactions. Our first aim was to develop a taxon co-occurrence analysis method that is also capable of taking into account the effect of species ranges and can handle faunistic records from museum databases or biodiversity inventories. Our second aim was to test the independence of taxon co-occurrences of rock-dwelling gastropods at different taxonomic levels, with a special focus on the Clausiliidae subfamily Alopiinae, and in particular the genus .

Taxonomic revision of the rock-dwelling door snail genus Montenegrina Boettger, 1877 (Mollusca, Gastropoda, Clausiliidae).

The genus Montenegrina is revised on the basis of material available at the Hungarian Natural History Museum (Budapest), Naturhistorisches Museum Wien (Vienna), and the Naturmuseum Senckenberg (Frankfurt am Main), as well as newly discovered populations. The following new taxa are described: Montenegrina haringae sp. n.

Identification and functional characterisation of a novel KCNJ2 mutation, Val302del, causing Andersen-Tawil syndrome.

Loss-of-function mutations of the KCNJ2 gene encoding for the inward rectifier potassium channel subunit Kir2.1 cause Andersen-Tawil Syndrome (ATS), a rare genetic disorder characterised by periodic paralysis, ventricular arrhythmias, and dysmorphic features. Clinical manifestations of the disease appear to vary greatly with the nature of mutation, therefore, functional characterisation of ATS-causing mutations is of clinical importance.

Differential expression of the brassinosteroid receptor-encoding BRI1 gene in Arabidopsis.

Brassinosteroid (BR)-regulated growth and development in Arabidopsis depends on BRASSINOSTEROID INSENSITIVE 1 (BRI1), the BR receptor that is responsible for initiating the events of BR signalling. We analysed the temporal and spatial regulation of BRI1 expression using stable transgenic lines that carried BRI1 promoter:reporter fusions. In both seedlings and mature plants the tissues undergoing elongation or differentiation showed elevated BRI1 gene activity, and it could be demonstrated that in the hypocotyl this was accompanied by accumulation of the BRI1 transcript and its receptor protein product.

CYP90A1/CPD, a brassinosteroid biosynthetic cytochrome P450 of Arabidopsis, catalyzes C-3 oxidation.

Brassinosteroids (BRs) are steroidal phytohormones that regulate plant growth and development. Whereas in Arabidopsis the network-like routes of BR biosynthesis have been elucidated in considerable detail, the roles of some of the biosynthetic enzymes and their participation in the different subpathways remained to be clarified. We investigated the function of the cytochrome P450 monooxygenase CYP90A1/CPD, which earlier had been proposed to act as a BR C-23 hydroxylase.

Cloning the bacterial bphC gene into Nicotiana tabacum to improve the efficiency of phytoremediation of polychlorinated biphenyls.

The aim of this work was to construct transgenic plants with increased capabilities to degrade organic pollutants, such as polychlorinated biphenyls. The environmentally important gene of bacterial dioxygenase, the bphC gene, was chosen to clone into a plant of Nicotiana tabacum. The chosen bphC gene encodes 2,3-dihydroxybiphenyl-1,2-dioxygenase, which cleaves the aromatic ring of dihydroxybiphenyl, and we cloned it in fusion with the gene for β-glucuronidase (GUS), luciferase (LUC) or with a histidine tail.

C-23 hydroxylation by Arabidopsis CYP90C1 and CYP90D1 reveals a novel shortcut in brassinosteroid biosynthesis.

Brassinosteroids (BRs) are biosynthesized from campesterol via several cytochrome P450 (P450)-catalyzed oxidative reactions. We report the functional characterization of two BR-biosynthetic P450s from Arabidopsis thaliana: CYP90C1/ROTUNDIFOLIA3 and CYP90D1. The cyp90c1 cyp90d1 double mutant exhibits the characteristic BR-deficient dwarf phenotype, although the individual mutants do not display this phenotype.

Diurnal regulation of the brassinosteroid-biosynthetic CPD gene in Arabidopsis.

Plant steroid hormones, brassinosteroids (BRs), are essential for normal photomorphogenesis. However, the mechanism by which light controls physiological functions via BRs is not well understood. Using transgenic plants carrying promoter-luciferase reporter gene fusions, we show that in Arabidopsis (Arabidopsis thaliana) the BR-biosynthetic CPD and CYP85A2 genes are under diurnal regulation.

Can tobacco have a potentially beneficial effect to our health?

With urgent pressure to clean up the contaminated environment, new approaches are needed. Phyto- and rhizoremediation using plants and related bacteria is a promising approach, but has its inborn limitations. To overcome the slow performance of the process, transgenic plants have been prepared specifically tailored for phytoremediation purposes.

Unique and overlapping expression patterns of Arabidopsis CYP85 genes involved in brassinosteroid C-6 oxidation.

Brassinosteroids (BRs) are steroid hormones that are essential for plant growth and development. To gain insight into potential sites of BR synthesis, we studied promoter activities of the two Arabidopsis BR C-6 oxidase genes (CYP85A1 and CYP85A2) in transgenic plants carrying promoter fusions with the GUS, GFP or LUC reporter genes. BR-dependent feedback regulation of the GUS reporter constructs indicated that their expression corresponded to those of the native genes.

Patterns of Dwarf expression and brassinosteroid accumulation in tomato reveal the importance of brassinosteroid synthesis during fruit development.

Brassinosteroids (BRs) are essential for many physiological functions in plants, however little is known concerning where and when they are synthesized. This is especially true during flower and fruit production. To address this we have used a promoter-GUS reporter fusion and RT-PCR to determine the relative expression levels of the tomato Dwarf (D) gene that encodes a BR C-6 oxidase.

Brassinosteroid and systemin: two hormones perceived by the same receptor.

Brassinosteroids, coordinating developmental events, and systemin, inducing systemic wound responses to attacks by insect pests, are newly recognized plant hormones that are perceived by plasma membrane-localized leucine-rich repeat receptor kinases. The recent characterization of the brassinosteroid receptor BRI1 from tomato revealed that this protein is identical to the previously isolated SR160 systemin receptor, strongly suggesting that both brassinosteroid and systemin signalling use the same surface receptor.

Regulation of transcript levels of the Arabidopsis cytochrome p450 genes involved in brassinosteroid biosynthesis.

Cytochrome P450 enzymes of the closely related CYP90 and CYP85 families catalyze essential oxidative reactions in the biosynthesis of brassinosteroid (BR) hormones. Arabidopsis CYP90B1/DWF4 and CYP90A1/CPD are responsible for respective C-22 and C-23 hydroxylation of the steroid side chain and CYP85A1 catalyzes C-6 oxidation of 6-deoxo intermediates, whereas the functions of CYP90C1/ROT3, CYP90D1, and CYP85A2 are still unknown. Semiquantitative reverse transcriptase-polymerase chain reaction analyses show that transcript levels of CYP85 and CYP90 genes are down-regulated by brassinolide, the end product of the BR biosynthesis pathway.

Characterisation of BRH1, a brassinosteroid-responsive RING-H2 gene from Arabidopsis thaliana.

Although many important aspects of plant development are controlled by brassinosteroids (BRs), the early molecular events of their hormonal action are largely unknown. Using a differential-display RT-PCR screen designed to detect early response transcripts, those regulated by BR treatment in the absence of de novo protein synthesis, we identified an Arabidopsis thaliana (L.) Heynh.