Callus Formation and Organogenesis of Potato (Solanum tuberosum L.) Cultivar Almera

A procedure for plant regeneration from callus culture of potato, Solanum tuberosum L. is described. Calli were induced from 1.0 cm2 tuber segment of potato cultivar Almera on Murashige and Skoog's medium (MS) supplemented with different levels (1.0-5.0 mg/l) of 2, 4-dichlorophenoxy acetic acid (2, 4-D). The highest degree of callus formation (3.0) and hundred percent (100%) of explants produced nodular calli on MS medium within 7-12 days when supplemented with 2.0-5.0 mg/l of 2, 4-D. Calli were differentiated into shoot-primordia when subcultured on MS medium supplemented with 1.5 -5.0 mg/l of thidiazuron (TDZ) and 2.0-5.0 mg/l of benzyladenine (BA).  The best result for number of shoot per callus (3.3 ± 0.3) and longest shoot (0.8 ± 0.1) were obtained by using TDZ at 5.0 mg/l. Callus derived shoots were rooted most effectively in full-strength MS medium containing 1.0 mg L-1 IBA. The success of plant tissue culture for in vitro culture of potato was encouraged by acclimatization of the plantlets in the greenhouse conditions. Regenerated plants were morphologically uniform with normal leaf shape and growth pattern

AtALMT12 represents an R-type anion channel required for stomatal movement in Arabidopsis guard cells

Stomatal pores formed by a pair of guard cells in the leaf epidermis control gas exchange and transpirational water loss. Stomatal closure is mediated by the release of potassium and anions from guard cells. Anion efflux from guard cells involves slow (S-type) and rapid (R-type) anion channels. Recently the SLAC1 gene has been shown to encode the slow, voltage-independent anion channel component in guard cells. In contrast, the R-type channel still awaits identification. Here, we show that AtALMT12, a member of the aluminum activated malate transporter family in Arabidopsis, represents a guard cell R-type anion channel. AtALMT12 is highly expressed in guard cells and is targeted to the plasma membrane. Plants lacking AtALMT12 are impaired in dark- and CO₂ -induced stomatal closure, as well as in response to the drought-stress hormone abscisic acid. Patch-clamp studies on guard cell protoplasts isolated from atalmt12 mutants revealed reduced R-type currents compared with wild-type plants when malate is present in the bath media. Following expression of AtALMT12 in Xenopus oocytes, voltage-dependent anion currents reminiscent to R-type channels could be activated. In line with the features of the R-type channel, the activity of heterologously expressed AtALMT12 depends on extracellular malate. Thereby this key metabolite and osmolite of guard cells shifts the threshold for voltage activation of AtALMT12 towards more hyperpolarized potentials. R-Type channels, like voltage-dependent cation channels in nerve cells, are capable of transiently depolarizing guard cells, and thus could trigger membrane potential oscillations, action potentials and initiate long-term anion and K(+) efflux via SLAC1 and GORK, respectively

Redefinition and Reassignment of the 18-cirri Genera Hemigastrostyla, Oxytricha, Urosomoida, and Actinotricha (Ciliophora, Hypotricha), and Description of One New Genus and Two New Species

The morphology, the infraciliature, and two stages of physiological reorganization of Hemigastrostyla elongata spec. nov.,isolated from the Yellow Sea near Qingdao (China), are described. The new species differs from the type H. stenocephala, inter alia, by the length of the dorsal bristles and the position of the pretransverse ventral cirri; from H. enigmatica by the number of caudal cirri; and from H. para-enigmatica spec. nov. – established for the H. enigmatica populations from the Yellow Sea – by the arrangement of the postoral ventral cirri and the cortical granulation. A key to the Hemigastrostyla species and some other 18-cirri hypotrichs is provided. Hemigastrostyla szaboi is fixed as type species of Heterooxytricha gen. nov. because the type population lacks the extra cirri which are characteristic for Hemigastrostyla. In addition, Oxytricha geleii is assigned to this new genus, whose species have, like many oxytrichids, 18 frontal-ventraltransverse cirri, but a Gonostomum dorsal kinety pattern. The old, large, and difficult genus Oxytricha is briefly reviewed, mainly on the basis of the dorsal kinety pattern. Very likely, only species with the Oxytricha pattern belong to this genus. Oxytricha marcili and O. pseudofurcata, which have the Urosomoida kinety pattern (i.e. kinety 3 fragmentation lacking), are transferred to Urosomoida which is, inter alia, defined by a more or less distinctly reduced number of ventral and transverse cirri. Some other Oxytricha species with this kinety pattern (O. islandica, O. lanceolata, O. pseudosimilis, O. setigera) are not transferred to Urosomoida, but preliminarily classified as incertae sedis in Oxytricha, because they have the full set of 18 cirri. The available molecular data on O. lanceolata indicate that this type of 18-cirri hypotrichs likely needs a genus of its own because O. lanceolata does not cluster with O. granulifera, type of this genus. The marine Actinotricha saltans, classified for a very long time in Oxytricha, seems to be a non-dorsomarginalian hypotrich according to molecular data, justifying the reactivation of the old genus Actinotricha. Oxytricha shii has a multiple dorsal kinety 3 fragmentation, three dorsomarginal rows, and the undulating membranes arranged in the Cyrtohymena pattern, strongly indicating that it is a member of the subgenus Cyrtohymena (Cyrtohymenides). This brief review is a further step to unravel the complicated systematics of the old, but still little-known genus Oxytricha. The following new combinations are made in this paper: Cyrtohymena (Cyrtohymenides) shii (Shi et al., 1997) comb. nov.; Heterooxytricha szaboi (Wilbert and Song, 2005) comb. nov.; Heterooxytricha geleii (Wilbert, 1986) comb. nov.; Urosomoida marcili (Paiva and Silva-Neto, 2004) comb. nov.; Urosomoida pseudofurcata (Berger, 1999) comb. nov

Guard Cell-Specific Calcium Sensitivity of High Density and Activity SV/TPC1 Channels

The slow vacuolar (SV) channel, a Ca2+-regulated vacuolar cation conductance channel, in Arabidopsis thaliana is encoded by the single-copy gene AtTPC1. Although loss-of-function tpc1 mutants were reported to exhibit a stoma phenotype, knowledge about the underlying guard cell-specific features of SV/TPC1 channels is still lacking. Here we demonstrate that TPC1 transcripts and SV current density in guard cells were much more pronounced than in mesophyll cells. Furthermore, the SV channel in motor cells exhibited a higher cytosolic Ca2+ sensitivity than in mesophyll cells. These distinct features of the guard cell SV channel therefore probably account for the published stomatal phenotype of tpc1-

Calcium sensor kinase activates potassium uptake systems in gland cells of Venus flytraps

The Darwin plant Dionaea muscipula is able to grow on mineral-poor soil, because it gains essential nutrients from captured animal prey. Given that no nutrients remain in the trap when it opens after the consumption of an animal meal, we here asked the question of how Dionaea sequesters prey-derived potassium. We show that prey capture triggers expression of a K+ uptake system in the Venus flytrap. In search of K+ transporters endowed with adequate properties for this role, we screened a Dionaea expressed sequence tag (EST) database and identified DmKT1 and DmHAK5 as candidates. On insect and touch hormone stimulation, the number of transcripts of these transporters increased in flytraps. After cRNA injection of K+-transporter genes into Xenopus oocytes, however, both putative K+ transporters remained silent. Assuming that calcium sensor kinases are regulating Arabidopsis K+ transporter 1 (AKT1), we coexpressed the putative K+ transporters with a large set of kinases and identified the CBL9-CIPK23 pair as the major activating complex for both transporters in Dionaea K+ uptake. DmKT1 was found to be a K+-selective channel of voltage-dependent high capacity and low affinity, whereas DmHAK5 was identified as the first, to our knowledge, proton-driven, high-affinity potassium transporter with weak selectivity. When the Venus flytrap is processing its prey, the gland cell membrane potential is maintained around -120 mV, and the apoplast is acidified to pH 3. These conditions in the green stomach formed by the closed flytrap allow DmKT1 and DmHAK5 to acquire prey-derived K+, reducing its concentration from millimolar levels down to trace levels

Déclin précipité du Triton de Poiret Pleurodeles poireti Gervais, 1835 et autres changements du statut des amphibiens de Numidie, Algérie du Nord-Est

The worldwide erosion of biological diversity has not spared amphibians which are amongst the most affected taxa with numerous extinct or near-extinct species. Our knowledge of the status and ecology of amphibians of Algeria is still limited whereas local natural habitats are fast disappearing under a strong anthropogenic pressure. Eighty two localities were sampled between 1996 and 2010, to survey the amphibian community within Numidia, North-Eastern Algeria. Nine species, three Urodeles (Pleurodeles poireti, Pleurodeles nebulosus and Salamandra algira and six Anurans (Bufo bufo spinosus, Bufo mauritanicus, Bufo viridis, Discoglossus pictus, Hyla meridionalis and Pelophylax saharicus) were found within the region. Results suggest a marked, rapid and unexplained crash of the Algerian Newt Pleurodeles poireti, a species endemic to a small area in and around Djebel Edough (Annaba). Information on the status (abundance and distribution) of each recorded taxon is provided and conservation measures are discussed in the light of an apparent local decline of Anurans and the vulnerability of three species (S. algira, P. nebulosus and B. bufo spinosus)La crise aiguë que traverse la biodiversité à l'échelle planétaire n'a pas épargné les amphibiens qui figurent parmi les taxons les plus touchés, illustrés par le déclin prononcé ou la disparition de plusieurs espèces. Notre connaissance du statut et de l'écologie des amphibiens d'Algérie reste limitée alors que les milieux naturels locaux subissent une pression anthropique intense qui ne fait que s'accroître et qui risque de s'exacerber sous l'effet du réchauffement climatique. Dans le but d'inventorier et d'évaluer le statut du peuplement d'amphibiens du complexe de zones humides de la Numidie, «point chaud» pour de nombreux taxons aquatiques et poche relictuelle afrotropicale, nous avons échantillonné 82 sites entre 1996 et 2010. Un total de neuf espèces dont trois Urodèles (Pleurodeles poireti Gervais, 1835, Pleurodeles nebulosus (Guichenot, 1850) et Salamandra algira Bedriaga, 1883) et six Anoures (Bufo bufo spinosus, Bufo mauritanicus Schlegel, 1841, Bufo viridis Laurenti, 1768, Discoglossus picrus Otth, 1837, HYla meridionalis Boettger, 1874 et Pelophylax saharicus Boulanger in Hartert, 1913) ont été inventoriées. Un fait marquant est le déclin net, rapide et inexpliqué du Triton de Poiret Pleurodeles poireti, espèce endémique à une région limitée au Djebel Edough et ses environs, au cours des dernières années. Le statut de trois espèces (S. algira, P. nebulosus and B. bufo spinosus) semble préoccupant au vu des pressions anthropogéniques qui s'exercent sur la Numidie qui abrite 82% des amphibiens d'Algérie

Morphology and SSU rRNA Gene Sequences of Three Marine Ciliates from Yellow Sea, China, Including One New Species, Uronema heteromarinum nov. spec. (Ciliophora, Scuticociliatida)

The morphology, infraciliature, and silverline system of three marine scuticociliates, Uronema marinum Dujardin, 1841, U. heteromarinum nov. spec. and Pleuronema setigerum Calkins, 1902, isolated from coastal waters off Qingdao, China, were investigated using living observation and silver impregnation methods. Due to the great confusion in the species definition of the well-known species U. marinum, we have documented a detailed discussion/comparison and believe that most of the confusion is due to the fact that at least 2 closely-related sibling morphotypes exist which are often not recognized. Based on the data available, U. marinum is strictly defined as follows: marine Uronema ca. 30 × 10 μm in size, with truncated apical frontal plate and smooth pellicle, extrusomes inconspicuous, cytostome located equatorially, 12–14 somatic kineties and one contractile vacuole pore near posterior end of kinety 2. Uronema heteromarinum nov. spec. resembles U. marinum but can be distinguished morphologically by its notched pellicle with conspicuous extrusomes and reticulate ridges, the 15–16 somatic kineties, widely separated membranelle 1 and membranelle 2, as well as the subequatorially positioned cytostome. Based on the Qingdao population, an improved diagnosis for the poorly known Pleuronema setigerum is: marine slender oval-shaped form, in vivo about 40–50 × 15–20 μm; 3–5 preoral kineties and 14–22 somatic kineties; membranelle 1 and 3 three-rowed, and posterior end of M2a ring-like. The small subunit (SSU) rRNA gene for all three organisms were sequenced and analyzed with standard methods

Apogastrostyla rigescens (Kahl, 1932) gen. nov., comb. nov. (Ciliophora, Hypotricha): Morphology, Notes on Cell Division, SSU rRNA Gene Sequence Data, and Neotypification

The morphology, the infraciliature, some stages of cell division and physiological reorganization, and the SSU rRNA gene sequence of the little-known marine 18-cirri hypotrich Tachysoma rigescens (Kahl, 1932) Borror, 1972 [basionym Oxytricha (Tachysoma) rigescens], isolated from mariculture waters near Qingdao, China, were investigated. This rare species is characterized, inter alia, by narrowly spaced, small, colourless cortical granules and several conspicuous ring-shaped structures in the cytoplasm. The caudal cirri and the simple dorsal kinety pattern (three bipolar kineties) are probably plesiomorphic traits within the Hypotricha, the composition of the adoral zone of the proter from new and parental membranelles, as well as the presence of two ‘extra’ cirri behind the right marginal row strongly suggest a misclassification in Tachysoma. The SSU rRNA gene sequence data indicate that T. rigescens branches off rather basally in the Hypotricha tree, which supports the hypothesis that the 18-cirri pattern occurred very early, probably already in the last common ancestor of the Hypotricha. A detailed survey of the early branching 18-cirri hypotrichs and similar taxa (e.g. Trachelostyla pediculiformis, Hemigastrostyla enigmatica, Protogastrostyla pulchra) reveals that for T. rigescens a new genus (Apogastrostyla gen. nov.) has to be established, because there are important differences, inter alia, in the dorsal infraciliature. Besides the type species, A. rigescens comb. nov., which seems to be confined to the northern hemisphere according to the sparse faunistic data, a second marine species, A. szaboi comb. nov. (basionym Hemigastrostyla szaboi), so far only twice recorded from the Antarctic region, can be included. The Chinese population is fixed as neotype to define the species objectively, because no type material of A. rigescens is present and the original type locality is not known. The species name Tachysoma multinucleate is emended: Tachysoma multinucleatum nom. corr

Taxonomic Studies on Three Marine Ciliates from China, Including a New Species (Ciliophora, Cyrtophorida)

The present work investigates the living morphology and infraciliature of three marine cyrtophorid ciliates, which were isolated from Qingdao, China. Compared with its congeners, Orthotrochilia sinica spec. nov. can be distinguished by a combination of features: body slender and elliptical in outline, size about 50–60 × 20–25 μm in vivo, 18–21 somatic kineties, the length of the left perioral kinety treble the length of the right one, two ventrally located contractile vacuoles on the right side, and 25–32 nematodesmal rods. Based on current observations and the previous description, the diagnosis of Trochilioides tenuis (Deroux, 1976) Chen et al. 2011 is improved: cell size 30–40 × 20–35 μm in vivo, oval shaped in outline; consistently three right kineties, four left kineties and seven postoral kineties; a single contractile vacuole; marine habitat. A second species of Trochilioides, T. recta (Kahl, 1923) Chen et al. 2011 is re-described based on a Chinese population. Furthermore, a key to the identification of species of the genus Trochilioides whose infraciliature data are available is supplied, and Chlamydonyx trivialis (Fenchel, 1965) comb. nov. [basionym: Trochilioides trivialis Fenchel, 1965] is suggested

Morphology and Phylogeny of Four Marine Scuticociliates (Protista, Ciliophora), with Descriptions of Two New Species: Pleuronema elegans spec. nov. and Uronema orientalis spec. nov.

The morphology and infraciliature of four marine scuticociliates, Pleuronema elegans spec. nov., P. setigerum Calkins, 1902, P. grolierei Wang et al., 2008 and Uronema orientalis spec. nov., collected from China seas, were investigated through live observation and protargol staining methods. Pleuronema elegans spec. nov. can be recognized by the combination of the following characters: size in vivo 90–115 × 45–60 µm, slender oval in outline with a distinctly pointed posterior end; about 10 prolonged caudal cilia; consistently two preoral kineties and 18 or 19 somatic kineties; membranelle 2a double-rowed with its posterior end straight; membranelle 3 three-rowed; one macronucleus; marine habitat. Uronema orientalis spec. nov. is distinguished by the following features: in vivo about 40–55 × 20–30 μm with a truncated apical plate; consistently twenty somatic kineties; membranelle 1 single-rowed and divided into two parts which comprise four and three basal bodies respectively; contractile vacuole pore positioned at the end of the second somatic kinety; marine habitat. We also provide improved diagnoses for P. grolierei Wang et al., 2008 and P. setigerum Calkins, 1902 based on current and previous reports. The small subunit rRNA gene of U. orientalis, P. elegans, P. grolierei and P. puytoraci were sequenced. Phylogenetic analyses indicate that Uronema and Pleuronema are not monophyletic