Miklos Szekeres

Biological Research Centre, Hungarian Academy of Sciences | BRC · Institute of Plant Biology

The Caucasus ecoregion is one of the most important biodiversity hotspots in western Eurasia. Georgia is situated in the middle of this area, between the ranges of the Greater and Lesser Caucasus, a position providing exceptionally balanced environmental conditions for its flora and fauna. Animal groups of low mobility, such as land snails, are imp...

The Clausiliidae species of India, Myanmar, Pakistan and Sri Lanka are mostly endemic and among the least stud�ied representatives of their family. Almost all of the available material of these taxa was collected before 1920 and is housed in the Natural History Museum, London. The present overview of this collection provides information on the orig...

Southeast Asian Clausiliidae in the collection of the Florida Museum of Natural History, and particularly those that were obtained during recent biodiversity surveys in Myanmar and Thailand, provide important new data on the mostly endemic species of the family in that region. This paper assesses the museum’s clausiliid material from continental So...

Recent field trips yielded valuable new information on the Clausiliidae of some little-researched regions of Myanmar, Thailand and central Vietnam. Indonenia admirabilis Grego & Szekeres sp. nov., Margaritiphaedusa grata Hunyadi & Szekeres sp. nov. and Phaedusa kazueae Hunyadi & Szekeres sp. nov. are introduced as new taxa, and occurrence records a...

From recently received material Bathyptychia (Bathyptychia) zechuani n. sp., Dautzenbergiella (Dautzenbergiella) leekremeri n. sp., Dautzenbergiella (Dautzenbergiella) yanghaoi n. sp., Serriphaedusa (Serriphaedusa) tenuispira n. sp., Serriphaedusa (Gibbophaedusa) zhangqingae n. sp., and Synprosphyma yunlingi n. sp. are described as new taxa. Their...

Rock‐dwelling gastropods are usually patchily distributed in limestone habitats, presumably have low active and passive dispersal ability and often represent narrow‐ranged endemic taxa. Their current taxonomy is predominantly shell morphology based, and it remains unknown whether the morphologically differentiated and geographically separated popul...

Pontophaedusa gregoi sp. nov. is described from the Imereti Region of Georgia. This is the second species of a Tertiary relict genus that represents a very early diverged lineage of the Phaedusinae subfamily. The differences between the shell characters and climatic preferences of the Pontophaedusa species are discussed.

Pontophaedusa gregoi sp. nov. is described from the Imereti Region of Georgia. This is the second species of a Tertiary relict genus that represents a very early diverged lineage of the Phaedusinae subfamily. The differences between the shell characters and climatic preferences of the Pontophaedusa species are discussed.

Reproductive anatomy, including morphology of the inner penial wall, and shell morphology of all five species hitherto classified in Sumelia Nordsieck, 1994 have been investigated. This resulted in the recognition of a new genus, Blaeneuxina n. gen. (type species: Euxina recedens Németh & Szekeres, 1995) and a new subgenus, Sumelia (Neubertia) (typ...

Abstract: Formosana renzhigangi n. sp. and Serriphaedusa (Gibbophaedusa) gerberi n. sp. are described from Yunnan Province of southern China. Additionally, new occurrence records of Papilliphaedusa kunmingensis (Chen et Zhang, 1999) are provided. The composition and diversity of Yunnan’s Clausiliidae fauna, its relation to those of the adjacent zoo...

sp. nov., a new member of the Clausiliidae subfamily Phaedusinae is described from the Hai Van Mountain in central Vietnam. The relationship of the new species to other taxa of the genus and the zoogeographical importance of species in Southeast Asia are discussed.

Alopia livida (Menke) is one of the widest distributed species of its primarily limestone-dwelling genus that is native to the Romanian Carpathians. Its discontinuous range includes large parts of the Bucegi Mts and a few scattered occurrences westward to the Apuseni mountain complex. Here we provide description of A. livida vargabandii Fehér et Sz...

Recently obtained mollusc samples provided valuable new information on the Clausiliidae of Laos, Vietnam, and China’s Yunnan Province. Grandinenia dautzenbergi abdoui Grego & Szekeres subsp. nov., Grandinenia muratovi Grego & Szekeres sp. nov., Oospira duci smidai Grego & Szekeres subsp. nov., Phaedusa micropaviei hmongorum Grego & Szekeres subsp....

In total, 51 terrestrial gastropod taxa are recorded from the Prespa National Park, Albania. Seven species are local endemics for the region of Lake Prespa and adjacent mountains, eight are West-Balkan endemics and seven are Balkan endemics. There are no species considered threatened according to the IUCN categories and only one species, Orcula wag...

The sections in this article are Introduction Metabolism Signal Transduction Future Prospectives Acknowledgements

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 taki...

Based on recently collected Chinese material Tropidauchenia sulcicollis n. sp., Tropidauchenia yanghaoi n. sp., Synprosphyma ambigua n. sp., Synprosphyma segersi n. sp., Oospira yanghaoi n. sp., Formosana kremeri n. sp., Dautzenbergiella (Mansuyiella) paulae n. sp., Fuchsiana zhangqingae n. sp., Serriphaedusa (Gibbophaedusa) poppei n. subgen. n. sp...

From China Acanthophaedusa reductans n.sp., Bacillophaedusa annularis n. gen. n.sp., Cirrophaedusa plicilabris n. gen. n.sp., Distortiphaedusa imprimata n. gen. n.sp., Falsiluna harryleei n. gen. n.sp., Phaedusa (Metaphaedusa) matejkoi n.sp., Selenophaedusa diplochilus griffithsi n. subsp., Serriphaedusa boissieaui n.sp. , Synprosphyma yanghaoi n.s...

Three new species of Oospira Blanford, 1872, namely O. dancei Dharma & Szekeres spec. nov. (Lampung Province, Batukeramat), O. butoti Grego & Szekeres spec. nov. (Aceh Province, Ratawali), and O. acehensis Dharma & Szekeres spec. nov. (Aceh Province, Pantansile), are described from Sumatera, Indonesia. The zoogeographical affinities of these taxa a...

Recently collected materials held at the Musée National d’Histoire Naturelle (Paris) yielded important new information on the Clausiliidae of Laos and Vietnam. The data considerably increase and refine the hitherto scarce knowledge on the distribution of the Garnieria Bourguignat, 1877 and Grandinenia Minato & Chen, 1984 species of Laos, and reveal...

Cotyorica nemethi n. sp., one of the Tertiary relict western members of the geographically disjunct subfamily Phaedusinae, is described from Ordu Province of northern Turkey. It shows similarity to the species of the subterranean genera Graecophaedusa Rähle, 1982 and Nothoserrulina Németh & Szekeres, 1995 having high positioned lamellae inferior an...

Acrotoma (Castelliana) likharevi sp. nov., Acrotoma (Castelliana) reshaviensis sp. nov., and Micropontica (Baleopsina) olgae sp. nov. are described from the Bzyb Mountains of Abkhazia. The taxonomic position, relation to congeneric taxa, and zoogeographical significance of the new taxa are discussed.

From the provinces Guangxi, Guizhou, Hunan, Sichuan and Yunnan the following taxa are described as new: Grandinenia pallidissima ooharai subsp. nov., Synprosphyma aegrota sp. nov., S. basilissa ishibei subsp. nov., S. hosodai sp. nov., S. ookuboi sp. nov., S. pallgergelyi sp. nov., S. wanshinensis monachorum subsp. nov., Oospira minutissima sp. nov...

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: M. haringae sp. n., M. lillae sp. n., M. prokletiana sp....

Montenegrina is an obligate rock-dwelling door-snail genus, associated with habitats of limestone outcrops. The geographic range of Montenegrina includes the coastal regions of Montenegro south of the Bay of Kotor, Albania, western Macedonia, and northwestern Greece. In geographical terms it extends from the southernmost parts of the Dinaric Mounta...

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,...

Based on materials from recent field trips Grandinenia gabijakabi Grego & Szekeres spec. nov. (from Quang Binh Province), Grandinenia steffeki Grego & Szekeres spec. nov. (from Nghe An Province), Oospira abstrusa ginkae Grego & Szekeres subspec. nov. (from Dien Bien Province), Oospira naggsi Luong & Szekeres spec. nov. (from Dong Nai Province) and...

The Caucasus region is among the most important Eurasian biodiversity hotspots (Zazanashvili et al. 2004, Walther et al. 2014). Its mollusc fauna is far from being well-explored and, as indicated by a number of recent studies, one could reasonably expect further taxonomical discoveries in this region. The diversity and distribution of the mollusc f...

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 se...

Whereas the vast majority of gastropods possess dextral shell and body organization, members of the Clausiliidae family are almost exclusively sinistral. Within this group a unique feature of the alpine genus Alopia is the comparable representation of sinistral and dextral taxa, and the existence of enantiomorph taxon pairs that appear to differ on...

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...

Brassinosteroids (BRs) participate in the regulation of important physiological processes, such as germination, photomorphogenesis, elongation, and the development of reproductive organs. Unlike other phytohormones, BRs are not subject to active transport within the plant, therefore, their levels are determined by the balance between local biosynth...

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, w...

The aim of this work is to increase the efficiency of the biodegradation of polychlorinated biphenyls (PCBs) by the introduction of bacterial genes into the plant genome. For this purpose, we selected the bphC gene encoding 2,3-dihydroxybiphenyl-1,2-dioxygenase from Pseudomonas testosteroni B-356 to be cloned into tobacco plants. The dihydroxybiphe...

Brassinosteroids (BRs) are important regulators of morphogenic events during plant development. The lack of active transport and well-characterized biosynthesis offer ideal condi- tions for studying the local and temporal effects of this hormone group. While recent studies have found clear coincidence between the sites of BR accumulation and organ...

Several approaches to the containment and treatment of contaminated sediment were evaluated, including the efficacy of adding activated carbon to sediment as an in-situ stabilization method and the use of conventional and innovative treatment caps. The applicability of phytoremediation for dredged sediments and sediments in shallow water or wetland...

BRs (brassinosteroids) are plant steroid hormones that are essential for normal plant development. The dramatic dwarfism exhibited by mutants in the CYP (cytochrome P450) enzymes involved in BR biosynthesis indicates a role for these hormones in plant growth and development. Since the mid-1990s, collaborative research has been geared towards develo...

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,...

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...

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...

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. Ou...

BBSRC grant P13908/Human Frontier Research Program (HFSP) to GB and TY / Royal Society, STA in Japan / the Hungarian Scientific Research Fund (Grant T 42639) and travel grants from the Royal Society and the British Council

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 f...

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 pro...

Brassinosteroids which show high structural similarity to animal steroid hormones elicit a variety of growth responses when exogeneously applied to plant tissues. Thus far however, the function of endogeneous brassinosteroids in higher plants has been unclear. This paper describes three extremely dwarfed Arabidopsis thaliana mutants, cbb1 (dwf1-6),...

The purpose of this investigation was to engineer genetically modified plants bearing the bacterial gene bphC coding for 2,3-dihydroxybiphenyl-1,2-dioxygenase. Gene bphC from Comamonas testosteroni B-356 was cloned into plasmid pBI 121 containing CaMV 35S promotor and kanamycine resistance and introduced into Agrobacterium tumefaciens LBA 4404. Pla...

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 intermediate...

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 a...

Plant photomorphogenesis is regulated by at least three different types of photoreceptors, among them the best characterized is phytochrome. Throughout their development plants express several types of phytochrome apoproteins that are encoded by members of a small multigene family. Two genes have been isolated from Nicotiana tabacum, designated Nt-...

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 intermediat...

Seven new taxa of Balkan clausiliids, Agathylla biloba martae ERÖSS & SZEKERES ssp.n. from W Albania, near Ibë, Montenegrina perstriata diminuta FEHÉR & SZEKERES ssp.n. from SW Macedonia, NE of Ohrid, Montenegrina perstriata crassa ERÖSS & SZEKERES ssp.n. from W Macedonia, near Modric, Montenegrina helvola cannata ERÖSS & SZEKERES ssp.n. from SW Al...

UV-B irradiation of intactSynechocystis sp. PCC 6803 cells results in the loss of photosystem II activity, which can be repaired via de novosynthesis of the D1 (and D2) reaction center subunits. In this study, we investigated the effect of UV-B irradiation on the transcription of the psbA2 and psbA3 genes encoding identical D1 proteins. We show tha...

The Arabidopsis CPD gene encodes a cytochrome P450 steroid side-chain hydroxylase (CYP90) that plays an essential role in the biosynthesis of the plant hormone brassinolide. Expression of the CPD gene is confined to cotyledons and leaf primordia in etiolated seedlings and detectable in the adaxial parenchyma of expanding leaves in light-grown plant...

The Arabidopsis CPD gene encodes a cytochrome P450 steroid side-chain hydroxylase (CYP90) that plays an essential role in the biosynthesis of the plant hormone brassinolide. Expression of the CPD gene is confined to cotyledons and leaf primordia in etiolated seedlings and detectable in the adaxial parenchyma of expanding leaves in light-grown plant...

Recent analysis of several constitutive photomorphogenic Arabidopsis mutants, defective in brassinosteroid biosynthesis or signaling, provided unequivocal evidence for the essential phytohormone function of brassinosteroids. From earlier studies a wealth of information is available regarding the occurrence of these steroids and their potential inte...

Recent reductions in the stratospheric ozone layer allowing more ultraviolet-B (UV-B, 280–320 nm) radiation to reach the Earth have initiated extensive research efforts to elucidate molecular mechanisms regulating responses of various organisms to UV irradiation. In photosynthetic organisms, a crucial part of the overall UV-B effect is related to d...

The cpd mutation localized by T-DNA tagging on Arabidopsis chromosome 5-14.3 inhibits cell elongation controlled by the ecdysone-like brassinosteroid hormone brassinolide. The cpd mutant displays de-etiolation and derepression of light-induced genes in the dark, as well as dwarfism, male sterility, and activation of stress-regulated genes in the li...

We have isolated a 1104 bp tobacco cDNA clone (H1c12) which includes an 846 bp open reading frame. This encodes a polypeptide of 282 amino acid residues and represents the largest plant H1 histone identified so far. The structure of the deduced protein shows the classical tripartite organization of the H1-type linker histones. The expression of the...

We have isolated a 1104 bp tobacco cDNA clone (H1c12) which includes an 846 bp open reading frame. This encodes a polypeptide of 282 amino acid residues and represents the largest plant H1 histone identified so far. The structure of the deduced protein shows the classical tripartite organization of the H1-type linker histones. The expression of the...

Serrulina (Pamphylica) n. subgen (type species: multidentifera Neubert), Cristataria intersita n. sp. and Euxina recedens n. sp. are proposed as taxa new to the Turkish Clausiliidae fauna. Based on anatomical structures, the systematic position of the previously little-known Chavchetia difficilis Retowski and Kazancia lindholmi Lindholm (formerly a...

Previously the characterisation of plant cells with different functions were based on morphological and physiological studies. Using the methods of molecular biology, i.e. reporter gene systems and plant transformation technology plant cells can be further defined by the genes they express (Edwards and Coruzzi, 1990). Photosyntetic genes such as th...

The ferredoxin-thioredoxin reductase variable subunit gene of Anacystis nidulans was cloned, and its nucleotide sequence was determined. A single-copy 219-bp open reading frame encoded a protein of 73 amino acid residues, with a calculated Mr of 8,400. The monocistronic transcripts were represented in a 400-base and a less abundant 300-base mRNA fo...

The susceptibility of 2,6-diaminopurine (DAP)-containing bacteriophage DNA to several restriction and other endonucleases was examined. With the only exception of TaqI, these enzymes did not accept the modified base as a substitute for adenine. The phage DNA was extensively fragmented by the restriction endonucleases which recognize only G and C-co...