Molecular cloning and functional characterization of a Cu/Zn superoxide dismutase gene (<Emphasis Type="Italic">CsCSD1</Emphasis>) from <Emphasis Type="Italic">Cucumis sativus</Emphasis>

Superoxide dismutase (SOD) proteins, which are widely present in the plant kingdom, play vital roles in response to abiotic stress. However, the functions of cucumber SOD genes in response to environmental stresses remain poorly understood. In this study, a SOD gene CsCSD1 was identified and functionally characterized from cucumber (Cucumis sativus). The CsCSD1 protein was successfully expressed in E. coli, and its overexpression significantly improved the tolerance of host E. coli cells to salinity stress. Besides, overexpression of CsCSD1 enhanced salinity tolerance during germination and seedling development in transgenic Arabidopsis plants. Further analyses showed that the SOD and CAT (catalase) activities of transgenic plants were significantly higher than those of wild-type (WT) plants under normal growth conditions as well as under NaCl treatment. In addition, the expression of stress-response genes RD22, RD29B and LEA4-5 was significantly elevated in transgenic plants. Our results demonstrate that the CsCSD1 gene functions in defense against salinity stress and may be important for molecular breeding of salt-tolerant plants.     

Reaction of osmoregulatory system in juveniles of Russian sturgeon <Emphasis Type="Italic">Acipenser gueldenstaedtii</Emphasis> (Acipenseridae) on influence of comatotropin of carp <Emphasis Type="Italic">Cyprinus carpio</Emphasis>

For the first time by the example of juveniles of Russian sturgeon Acipenser gueldenstaedtii Brandt, the role of growth hormone of hypophysis in the osmotic regulation of acipenserids was studied, also the process of transformation of reserve chloride was described. In Russian sturgeon juveniles, administration of growth hormone of carp Cyprinus carpio at a dose of 1 mg per 1 g body weight causes changes in the fine structure of numerous reserve (undifferentiated) gill epithelial cells and thus stimulates their transformation into mature chloride cells involved in transport of monovalent ions. Increase in the number of chloride cells, on account of reserve cells, was accompanied by higher enzymatic activity of Na⁺/K⁺-ATPase in gill homogenates of the injected fish adapting to a hyperosmotic environment of salinity 12.5‰ (403 mosm/l) than in the intact fish under the same conditions but without hormonal treatment. Morphophysiological changes observed in the injected juveniles provided the more efficient dynamics of blood serum osmolarity under saline exposure than that in the intact fish. Their serum osmolality during the maximum rise (24 hours after the transfer of fish into the water of 12.5‰ salinity) was lower (p <0.01), than that of the intact fish. The inclusion of growth hormone in the osmoregulatory process was established.     

A description of the larvae of <Emphasis Type="Italic">Cinygmula unicolorata</Emphasis> Tshernova, 1979 and <Emphasis Type="Italic">Cinygmula malaisei</Emphasis> (Ulmer, 1927) (Ephemeroptera,Heptageniidae) from the Russian Far East

The larvae of Cinygmula malaisei (Ulmer, 1927) and Cinygmula unicolorata Tshernova, 1979 from the Russian Far East are described and illustrated. The larva of Cinygmula unicolorata is similar to those of Cinygmula putoranica Kluge, 1980 and Cinygmula uyka Gorovaya et Tiunova, 2013 but differs from the larva of C. uyka in the absence of gill filaments and from that of C. unicolorata in the shape of the first gill (tergalia). The upper outer margin of the first gill is rounded in the larva of C. unicolorata and almost straight in C. putoranica; the gills of C. unicolorata are matte and the trachea is poorly expressed, in contrast to the distinctly brown trachea of C. putoranica. The larvae of Cinygmula malaisei are similar to those of C. irina and C. autumnalis but differ from the latter in the presence of gill filaments. The larva of C. malaise differs from that of C. irina in the rounded outer margin of the first gill, the shape of gills VI and VII, and in the size of the leg segments.     

Ecological ranges and types of rarity in the Kuznetsk Alatau of some <Emphasis Type="Italic">Saussurea</Emphasis> DC. species

An analysis of indicator values of four Saussurea DC. species, S. baicalensis (Adams) B. L. Rob., S. frolowii Ledeb., S. salicifolia (L.) DC., and S. schanginiana (Wydl.) Fisch. ex Serg., have been carried out by the method of indicator scales of soil moisture and nutrient availability and salinity in more than 1600 relevés. The size of their ecological ranges and the values of their competitiveness in phytocenoses are determined. As a result of a comparison of the locality of local populations within the ecological range and their occurrence, the vulnerability of S. baicalensis, S. frolowii, S. salicifolia, and S. schanginiana in the Kuznetsk Alatau is evaluated. The types of rarity for these species in the Kuznetsk Alatau are determined.     

Heterologous expression of two <Emphasis Type="Italic">Physcomitrella patens</Emphasis> group 3 late embryogenesis abundant protein (LEA3) genes confers salinity tolerance in arabidopsis

Salinity stress is a major limiting factor in agriculture and adversely affecting the whole plant. As a halophyte, the moss Physcomitrella patens, has been suggested to be an ideal model plant to study salinity tolerance and adaption. Two abiotic stress-responsive Group 3 Late Embryogenesis Abundant protein genes had been identified in P. patens and named as PpLEA3-1 and PpLEA3-2, respectively. Functions of these two genes were analyzed by heterologous expressions in Arabidopsis, driven either by their native P. patens promoters or by the 35S CaMV constitutive promoter. Phenotype analysis revealed that pLEA3::LEA3, pLEA3::LEA3::GFP and 35S::LEA3::GFP transgenic lines had stronger salinity resistance than that in the wild type and empty-vector control. Further analysis showed that the contents of proline and soluble sugar were increased and the malondialdehyde (MDA) were repressed in these transgenic plants after exposure to salinity stress. Our observations indicate that these two Group 3 PpLEA genes played a role in the adaption to salinity stress.     

On the ecology of some species of genus <Emphasis Type="Italic">Stuckenia</Emphasis> (Potamogetonaceae) in lakes of Zabaykalsky krai and the Republic of Buryatia

This paper clarifies the distribution and ecology of representatives of the genus Stuckenia (S. chakassiensis (Kaschina) Klinkova, S. pectinata (L.) Börner, S. macrocarpa (Dobroch.) Tzvelev, and S. vaginata (Turcz.) Holub) in brackish and saline lakes in eastern Russia. It is shown that S. chakassiensis grows in most Transbaikal lakes with a high salinity instead of S. pectinata, as was described earlier. Therefore, the range of this interesting and still insufficiently known taxon significantly extends to the east of Russia. Being very common in the mineralized waters of West Siberia, S. macrocarpa was not observed in Transbaikalia. In soda waters of Transbaikalia, S. chakassiensis forms thickets with a rather high productivity.     

Screening of rice landraces (<Emphasis Type="Italic">Oryza sativa</Emphasis> L.) for seedling stage salinity tolerance using morpho-physiological and molecular markers

Traditional rice landraces of coastal area in Bangladesh are distinct regarding their phenotype, response to salt stress and yield attributes. With characterization of these landraces, suitable candidate genes for salinity tolerance could be identified to introgress into modern rice varieties. Therefore, the aim of this experiment was to uncover prospective rice landraces tolerant to salinity. Relying on morphological, biochemical and molecular parameters 25 rice genotypes were tested for salt tolerance at germination and seedling stage. At germination stage 0 and 12 dSm^?1 salinity were imposed on rice genotypes. Ward’s cluster analysis divided rice genotypes into three clusters (susceptible, moderately tolerant and tolerant) based on the physiological indices. The tolerant rice landraces to salinity were Sona Toly, Nakraji and Komol Bhog. At seedling stage screening was performed following IRRI standard protocol at 12 dSm^?1 salinity level. Based on all morphological and biochemical parameters Komol Bhog was identified as the highly salinity tolerant landrace while Bolonga, Sona Toly, Dud Sail, Tal Mugur and Nakraji were found as tolerant to salinity. Molecular characterization using two simple sequence repeats (SSR) markers, viz. RM121 and RM337 displayed Bolonga, Til Kapor, Panbra, Sona Toly, Bina Sail, Komol Bhog, Nakraji, Tilkapur, Gajor Goria and Gota were tolerant landraces through genetic similarity in dendrogram. These identified salt-resistant landraces can be used as promising germplasm resources for breeding salt-tolerant high-yielding rice varieties in future.     

The ultrastructure of the interstitial cells of the mesonephros in the teleost fishes of the Black Sea

The ultrastructure of cells that form mesonephros tissues in eight species of bony fish of the Black Sea, Gaidropsarus mediterraneus (L.), Lisa aurata (Risso), Trachurus mediterraneus (Staindachner), Diplodus annularis (L.), Spicara flexuosa (Rafinesque), Gobius niger jozo L., Mullus barbatus ponticus (Essipov) and Scorpaena porcus (L.), was studied. It was shown that the ultrastructure of agranulocytes and rodlet cells in the studied species is similar to that of cells in freshwater bony fish. The differences were observed in the number of ionocyte mitochondria, in the vesicle ultrastructure in the cells with radial vesicle array, and in the ultrastructure of the specific secondary granules of neutrophils and eosinophils.     

Revision of the genus <Emphasis Type="Italic">Melamphaes</Emphasis> (Melamphaidae): 7. oligo-raker species: <Emphasis Type="Italic">M. danae</Emphasis> and <Emphasis Type="Italic">M. pumilis</Emphasis>

Two species, M. danae Ebeling and M. pumilis Ebeling, belonging to the species group “M. simus” are described in the final part of the revision of oligo-raker species of the genus Melamphaes (Melamphaidae) (≤19 gill rakers on the first gill arch). The species M. danae is distributed in the Indian and Pacific oceans between 30° N and 30° S. In the Pacific Ocean, it is known up to 112° W. The species M. pumilis is distributed in the North Atlantic between 17° and 45° N, and the main catches have been conducted in the western part of the ocean. In the eastern part of the ocean, the catches are registered up to 28° W. A key for the identification of 21 oligo-raker species of the genus Melamphaes is presented.     

Ultrastructure of larval epidermis of the nemertean <Emphasis Type="Italic">Quasitetrastemma stimpsoni</Emphasis> (Chernyshev, 1992) (Hoplonemertea)

The ultrastructure of the epidermis of free-swimming larvae of the nemertean Quasitetrastemma stimpsoni was examined. At about 24 hours after hatching, the provisional epithelium of larva is 28–35 μm thick and consists of two layers of cells—peripheral and basal. The peripheral layer consists of multiciliated cells and two kinds of gland cells. The “basal cup” zone is formed from the vacuoles of basal cells. At about 50 hours after hatching, the definitive epithelium is 14–17 μm thick and exhibits a typical hoplonemertean structure. However, it has numerous yolk vesicles, few processes of granular basal cells, and a weakly developed dermis. Thus, the replacement of the provisional epithelium by the definitive one occurs in Q. stimpsoni at an earlier stage, compared to the hidden larva of Tetrastemma candidum.     

<Emphasis Type="Italic">In vitro</Emphasis> propagation of endangered <Emphasis Type="Italic">Mammillaria</Emphasis> genus (Cactaceae) species and genetic stability assessment using SSR markers

In vitro propagation protocols were established for endangered species of cacti Mammillaria hernandezii, M. dixanthocentron, and M. lanata. In vitro-germinated seedlings were used as the explant source. Three explant types were evaluated as apical, basal, and lateral stem sections. Shoot multiplication was achieved using Murashige and Skoog (MS) medium supplemented with benzyladenine, kinetin, meta-topolin, and thidiazuron in equimolar concentrations (0.0, 0.4, 1.1, 2.2, 4.4, and 8.9 μM). Shoot regeneration was obtained primarily in the lateral stem section explants. In M. hernandezii, an average of 7.4 shoots was regenerated in MS medium with 2.2 μM meta-topolin. M. dixanthocentron and M. lanata averaged 16.7 and 17.9 shoots/explant, respectively, in MS medium supplemented with 1.1 μM meta-topolin. Rooting occurred in MS medium without growth regulators. Three in vitro culture cycles were performed to validate the propagation protocols and to verify genetic stability. Shoots were collected in each cycle and genomic DNA was extracted. Amplified microsatellites were used to compare each genotype with its respective donor plant. Polymorphic information content analysis showed low levels of intra-clonal polymorphisms—M. hernandezii 0.04 and M. dixanthocentron and M. lanata both 0.12. More than 95% of the plants were successfully acclimatized in the greenhouse. After 12 months, plants of M. hernandezii reached the flowering stage; M. dixanthocentron and M. lanata flowered at 24 mo.     

Molecular phylogeny of pectinase genes <Emphasis Type="Italic">PGU</Emphasis> in the yeast genus <Emphasis Type="Italic">Saccharomyces</Emphasis>

Using yeast genome databases and literature data, phylogenetic analysis of pectinase PGU genes from 112 Saccharomyces strains assigned to the biological species S. arboricola, S. bayanus (var. uvarum), S. cariocanus, S. cerevisiae, S. kudriavzevii, S. mikatae, S. paradoxus, and the hybrid taxon S. pastorianus (syn. S. carlsbergensis) was carried out. A superfamily of divergent PGU genes was found. Natural interspecies transfer of the PGU gene both from S. cerevisiae to S. bayanus and from S. paradoxus to S. cerevisiae may, however, occur. Within the Saccharomyces species, identity of the PGU nucleotide sequences was 98.8–100% for S. cerevisiae, 86.1–95.7% for S. bayanus (var. uvarum), 94–98.3% for S. kudriavzevii, and 96.8–100% for S. paradoxus/S. cariocanus. For the first time, a family of polymeric PGU1b, PGU2b, PGU3b and PGU4b genes is documented for the yeast S. bayanus var. uvarum, a variety important for winemaking.     

Comparative analysis of otolith morphology in three species of <Emphasis Type="Italic">Scomber</Emphasis>

Geometric morphometrics is a quick and reliable approach to differentiate fish stocks based on the variation of otolith shapes. In this study, morphometric analysis of otolith shapes was used to differentiate three species of Scomber. The sagittae morphology of S. scombrus otolith is totally different from that of S. japonicus and S. australasicus. Multivariate analysis consistently showed that S. japonicus was morphologically similar to S. australasicus, whereas a significant difference in otolith shapes was detected between S. scombrus and other two species of Scomber. The rostrum, antirostrum, excisural notch and dorsal-posterior margin of the otolith reflect the main variations between the three species of Scomber. Shape indices and Fourier coefficients were used to discriminate fish species using analysis of variance and Fisher discriminant analysis. The shape indices successfully differentiated 100%, 95.7% and 96.4% of otoliths in S. japonicus, S. australasicus and S. scombrus, respectively, while the Fourier coefficients only discriminated 70.0%, 61.9% and 91.3% of the sagittae in S. japonicus, S. australasicus and S. scombrus. This study indicates that the shape analysis on the sagittae morphometrics of otoliths is a better method to differentiate species of Scomber.     

Revision of the genus <Emphasis Type="Italic">Melamphaes</Emphasis> (Melamphaidae): 6. oligo-raker species: <Emphasis Type="Italic">M. papavereus,M. simus,M. hubbsi</Emphasis>

Three oligo-raker species (≤19 rakers on the first gill arch) of the genus Melamphaes have been considered. A new species, M. papavereus, out of the group “M. typhlops” has been described from the Bay of Bengal of the Indian Ocean. M. simus and M. hubbsi out of the group “M. simus” have been revised. M. simus inhabits all oceans between 40° N and 40° S. M. hubbsi has been known from single specimens caught in the central part of the South Atlantic between 11° and 19° S.     

Complete chloroplast genome sequences of <Emphasis Type="Italic">Solanum commersonii</Emphasis> and its application to chloroplast genotype in somatic hybrids with <Emphasis Type="Italic">Solanum tuberosum</Emphasis>

Key message

Chloroplast genome of Solanum commersonii and S olanum tuberosum were completely sequenced, and Indel markers were successfully applied to distinguish chlorotypes demonstrating the chloroplast genome was randomly distributed during protoplast fusion.

Abstract

Somatic hybridization has been widely employed for the introgression of resistance to several diseases from wild Solanum species to overcome sexual barriers in potato breeding. Solanum commersonii is a major resource used as a parent line in somatic hybridization to improve bacterial wilt resistance in interspecies transfer to cultivated potato (S. tuberosum). Here, we sequenced the complete chloroplast genomes of Lz3.2 (S. commersonii) and S. tuberosum (PT56), which were used to develop fusion products, then compared them with those of five members of the Solanaceae family, S. tuberosum, Capsicum annum, S. lycopersicum, S. bulbocastanum and S. nigrum and Coffea arabica as an out-group. We then developed Indel markers for application in chloroplast genotyping. The complete chloroplast genome of Lz3.2 is composed of 155,525 bp, which is larger than the PT56 genome with 155,296 bp. Gene content, order and orientation of the S. commersonii chloroplast genome were highly conserved with those of other Solanaceae species, and the phylogenetic tree revealed that S. commersonii is located within the same node of S. tuberosum. However, sequence alignment revealed nine Indels between S. commersonii and S. tuberosum in their chloroplast genomes, allowing two Indel markers to be developed. The markers could distinguish the two species and were successfully applied to chloroplast genotyping (chlorotype) in somatic hybrids and their progenies. The results obtained in this study confirmed the random distribution of the chloroplast genome during protoplast fusion and its maternal inheritance and can be applied to select proper plastid genotypes in potato breeding program.

     

Increased trehalose biosynthesis improves <Emphasis Type="Italic">Mesorhizobium ciceri</Emphasis> growth and symbiosis establishment in saline conditions

Cicer arietinum (chickpea) is a legume very sensitive to salinity, and so are most of its rhizobial symbionts belonging to the species Mesorhizobium ciceri. We observed that exogenous trehalose (i.e., added to the growth medium) can significantly improve growth of M. ciceri strain Rch125 under moderate salinity. In order to test if endogenous trehalose (i.e., synthesized by the cell) could also enhance salt tolerance, strain Rch125 was genetically modified with various trehalose biosynthesis genes from Sinorhizobium meliloti 1021 (otsA, treS, treY) and Mesorhizobium loti MAFF 303099 (otsAB). We found that overexpression of otsA or otsAB, but not treS or treY, significantly improved M. ciceri Rch125 growth in saline media. This growth improvement correlated with enhanced trehalose accumulation in otsA- and otsAB-modified cells, suggesting that increased trehalose synthesis via trehalose-6-phosphate can enhance bacterial salt tolerance. Chickpea plants inoculated with M. ciceri Rch125 derivatives carrying extra otsAB or otsA genes formed more nodules and accumulated more shoot biomass than wild type inoculated plants when grown in the presence of NaCl. These results support the notion that improved salt tolerance of the bacterial symbiont can alleviate the negative effects of salinity on chickpeas, and that such improvement in M. ciceri can be achieved by manipulating trehalose metabolism.     

Higher phenotypic plasticity does not confer higher salt resistance to <Emphasis Type="Italic">Robinia pseudoacacia</Emphasis> than <Emphasis Type="Italic">Amorpha fruticosa</Emphasis>

A greenhouse experiment was conducted in which two leguminous species commonly used in the Yellow River Delta for vegetation restoration, Robinia pseudoacacia and Amorpha fruticosa, were subjected to five salt treatments: 0, 50, 100, 150, and 200 mmol L^?1. We aimed to determine which of the two species would be better suited for growth in a saline environment, and whether the acclimation capacity to salinity resulted from an inherently higher phenotypic plasticity. The results showed that salinity affected most growth and biomass parameters but had no effects on most leaf traits and physiological parameters of the two species. Height, relative growth rate of crown area, root biomass, and leaf mass ratio of R. pseudoacacia were reduced by higher salinity, while A. fruticosa was not affected. Chlorophyll a-to-chlorophyll b ratio and total antioxidative capacity of A. fruticosa increased with higher salinity, whereas those of R. pseudoacacia remained unchanged. Root mass ratio and vitamin C concentration of both species were not affected by salinity, whereas vitamin C concentration of A. fruticosa was higher than that of R. pseudoacacia. The root-to-shoot ratio of A. fruticosa was higher than that of R. pseudoacacia in most salt treatments. Of all leaf traits, only leaf area differed between treatments. R. pseudoacacia generally exhibited a greater plasticity than A. fruticosa in response to salinity, but A. fruticosa was more resistant to the higher salinities than R. pseudoacacia, and was thus a better candidate for vegetation restoration in saline areas.     

Phylogenetic characterization and morphological and physiological aspects of a novel acidotolerant and halotolerant microalga <Emphasis Type="Italic">Coccomyxa onubensis</Emphasis> sp. nov. (Chlorophyta,Trebouxiophyceae)

The genus Coccomyxa comprises green microalgae, which can be found worldwide in remarkably versatile aquatic and terrestrial ecosystems including symbiotic associations with a number of different hosts. In this study, we describe a new species, Coccomyxa onubensis, based on 18S and ITS ribosomal DNA (rDNA) sequence data. Coccomyxa onubensis was isolated from acidic water, and its ability to adapt to a wide range of acidic and alkaline pH values and to high salinity was analyzed. The long-term adaptation capacity of the microalga to such extreme conditions was evaluated by performing continuous repeated batches at selected salt concentrations and pH values. Adapted cultures of C. onubensis were found to yield high biomass productivities from pH 2.5 to 9, with maximum yields at acidic pH between 2.5 and 4.5. Moreover, C. onubensis was also found to adapt to salinities as high as 0.5 M NaCl, reaching biomass productivities that were similar to those of control cultures. Ultrastructural analysis by transmission electron microscopy of C. onubensis cells adapted to high salinity showed a robust response to hyperosmotic shock. Thus, C. onubensis was found to be acidotolerant and halotolerant. High biomass productivity over a wide range of pH and salinities denotes C. onubensis as an interesting candidate for various biotechnological applications including outdoor biomass production.     

Assessing biodegradation of furfuryl alcohol using <Emphasis Type="Italic">Pseudomonas putida</Emphasis> MTCC 1194 and <Emphasis Type="Italic">Pseudomonas aeruginosa</Emphasis> MTCC 1034 and its kinetics

The biodegradation of furfuryl alcohol (FA) in shake flask experiments using a pure culture of Pseudomonas putida (MTCC 1194) and Pseudomonas aeruginosa (MTCC 1034) was studied at 30 °C and pH 7.0. Experiments were performed at different FA concentrations ranging from 50 to 500 mg/l. Before carrying out the biodegradation studies, the bacterial strains were acclimatized to the concentration of 500 mg/l of FA by gradually raising 100 mg/l of FA in each step. The well acclimatized culture of P. putida and P. aeruginosa degraded about 80 and 66% of 50 mg/l FA, respectively. At higher concentration of FA, the percentage of FA degradation decreased. The purpose of this study was to determine the kinetics of biodegradation of FA by measuring biomass growth rates and concentration of FA as a function of time. Substrate inhibition was calculated from experimental growth parameters using the Haldane equation. Data for P. putida were determined as µ _max ?=?0.23 h^?1, K _s ?=?23.93 mg/l and K _i ?=?217.1 mg/l and for P. aeruginosa were determined as µ _max ?=?0.13 h^?1, K _s ?=?21.3 mg/l and K _i ?=?284.9 mg/l. The experimental data were fitted in Haldane, Aiba and Edwards inhibition models.