Photosynthetic parameters of sexually different parts of <Emphasis Type="Italic">Porphyra katadai</Emphasis> var. <Emphasis Type="Italic">hemiphylla</Emphasis> (Bangiales,Rhodophyta) during dehydration and re-hydration

Physiological data from extreme habitat organisms during stresses are vital information for comprehending their survival. The intertidal seaweeds are exposed to a combination of environmental stresses, the most influential one being regular dehydration and re-hydration. Porphyra katadai var. hemiphylla is a unique intertidal macroalga species with two longitudinally separated, color distinct, sexually different parts. In this study, the photosynthetic performance of both PSI and PSII of the two sexually different parts of P. katadai thalli during dehydration and re-hydration was investigated. Under low-grade dehydration the variation of photosystems of male and female parts of P. katadai were similar. However, after the absolute water content reached 42%, the PSI of the female parts was nearly shut down while that of the male parts still coordinated well and worked properly with PSII. Furthermore, after re-hydration with a better conditioned PSI, the dehydrated male parts were able to restore photosynthesis within 1 h, while the female parts did not. It is concluded that in P. katadai the susceptibility of photosynthesis to dehydration depends on the accommodative ability of PSI. The relatively lower content of phycobiliprotein in male parts may be the cause for a stronger PSI after severe dehydration.     

<Emphasis Type="Italic">Boletus kermesinus</Emphasis>, a new species of <Emphasis Type="Italic">Boletus</Emphasis> section <Emphasis Type="Italic">Luridi</Emphasis> from central Honshu,Japan

Boletus kermesinus, a new species of Boletus section Luridi, is fully described and illustrated based on the materials collected in subalpine coniferous forests of central Honshu, Japan. It has distinctive features of dark-red basidiomata having distinct viscidity in the pileus surface, usually unchanging flesh, discolorous red pores, and an entirely reticulate stipe becoming coarsely lacerate-rimose with age.     

Synthesis of orthogonally protected (<Emphasis Type="Italic">3R</Emphasis>,<Emphasis Type="Italic">4S</Emphasis>)- and (<Emphasis Type="Italic">3S</Emphasis>,<Emphasis Type="Italic">4S</Emphasis>)-4,5-diamino-3-hydroxypentanoic acids

Summary.  The paper describes two methods of the synthesis of ethyl (3R,4S)- and (3S,4S)-4-[(benzyloxycarbonyl)amino]-5-[(tert-butyloxycarbonyl)amino]-3-hydroxypentanoates, useful for the syntheses of edeine analogs. Differently N-protected (S)-2,3-diaminopropanoic acid was used as a substrate in both procedures. The absolute configuration of newly generated asymmetric carbon atoms C-3 in β-hydroxy-γ,δ-diamino products was assigned by means of ¹H NMR spectroscopy after their transformation into corresponding piperidin-2-ones. Received May 24, 2002 Accepted October 10, 2002 Published online December 18, 2002 Acknowledgment The authors are indebted to the Faculty of Chemistry, Technical University of Gdańsk for financial support. Authors' address: Zbigniew Czajgucki, M. Sc., Department of Pharmaceutical Technology and Biochemistry, Faculty of Chemistry, Technical University of Gdańsk, 11/12 Narutowicza St., 80-952 Gdańsk, Poland, Fax +48 58 347 11 44, E-mail: zmczaj@wp.pl     

<Emphasis Type="Italic">In vitro</Emphasis> biosynthesis of strictosidine using<Emphasis Type="Italic">lonicera japonica</Emphasis> leaf extracts and recombinant yeast

Strictosidine is a key intermediate in the biosynthesis of the terpenoid indole alkaloid (T1A) pathway. It results from a condensation reaction, catalyzed by strictosidine synthase (STR), between tryptamine and secologanin. We have now developed a useful method, based on enzyme-assisted synthesis, to produce strictosidine. Our procedure utilizes leaf extracts from Japanese honeysuckleLonicera japonica Thunb. as a secologanin source. In these experiments, an enzyme extract was prepared from transgenic yeastSaccharomyces cerevisiae that expresses theCatharanthus roseus STR (CrSTR) coding region. Strictosidine was then isolated with a 38% yield based on the initial amount of tryptamine in the enzymatic reaction.     

Temperature tolerance and survival of intertidal populations of the seagrass <Emphasis Type="Italic">Zostera noltii</Emphasis> (Hornemann) in Southern Europe (Ria Formosa,Portugal)

The dwarf seagrass Zostera noltii is an important primary producer in Atlantic coastal ecosystems from Mauritania to southern Norway and the Mediterranean Sea. Sessile intertidal organisms existing at the interface between marine and terrestrial environments may be particularly vulnerable to environmental change. In this study, we asked how near to thermal tolerance limits natural populations of Z. noltii are in the Ria Formosa coastal lagoon system in southern Portugal. We recorded the maximum temperatures in the Ria Formosa during the 2007 summer, and conducted experiments to determine the sub-lethal temperature of Z. noltii shoots sampled at two sites located at different tidal heights. Mortality rates and photosynthetic performance were recorded within a range of heat shock temperatures between 35 and 41°C. Survival was recorded ≤37°C, while higher temperatures led to a sudden drop in photosynthetic capacity followed by mortality (shoot loss) that occurred more rapidly with increasing temperatures. At 39°C and above, the rate of shoot mortality in both sites was close to 100%, occurring between 5 and 13 days after the heat shock. Survival was ca. 95 and 90% at 35 and 37°C, respectively. From these results for Z. noltii populations in the Ria Formosa we estimated sub-lethal temperature to be approximately 38°C for Z. noltii, close to the maximum of 36°C recorded in the summer 2007. Considering predicted trajectories in the coming decades, these results raise concern as to the future viability of intertidal Z. noltii populations near the southernmost edge of their distribution. Handling editor: S. M. Thomaz     

Activity-density of <Emphasis Type="Italic">Pardosa cribata</Emphasis> in Spanish citrus orchards and its predatory capacity on <Emphasis Type="Italic">Ceratitis capitata</Emphasis> and <Emphasis Type="Italic">Myzus persicae</Emphasis>

The wolf spider Pardosa cribata Simon is the most abundant ground-dwelling spider inhabiting citrus orchards in eastern Spain. However, little is known about its activity-density and its predatory role in the citrus agrosystem. Here we report on the activity-density of P. cribata monitored by pitfall traps, and on its capacity to prey on two citrus pests that appear both in the citrus canopy and the ground cover, Ceratitis capitata (Wiedemman) and Myzus persicae (Sulzer), respectively. Pardosa cribata was present in citrus orchards throughout the year, with a peak in spring and a higher peak in summer. Pardosa cribata preyed on adults and third-instar larvae but not on pupae of C. capitata. A type II functional response was obtained for teneral-like adults, with an estimated attack rate (a′) of 0.771 ± 0.213 days⁻¹ and a handling time (T _h) of 0.051 ± 0.013 days. Pardosa cribata also preyed efficiently on M. persicae, giving a type II functional response with an estimated attack rate and handling time of 2.833 ± 0.578 days⁻¹ and 0.031 ± 0.001 days, respectively. The data reported here indicate that this wolf spider could play an important role in regulating both these pests, and therefore might contribute to developing conservation biological control strategies for citrus pests. Handling Editor: Arne Jenssen.     

Variability of esterase patterns in adult flies of the <Emphasis Type="Italic">saltans</Emphasis> species group of <Emphasis Type="Italic">Drosophila</Emphasis> (subgenus <Emphasis Type="Italic">Sophophora</Emphasis>)

Esterases are known for their involvement in several physiological processes and high degree of polymorphism, in many organisms. Such polymorphism has been used to characterize species and species groups and to study genetic changes occurred in their evolutionary history. In the present study, the esterase patterns of 19 strains from 10 species representative of the five subgroups of the saltans species group were analyzed using polyacrylamide gel electrophoresis and α- and β- naphthyl acetates as substrates. Fifty-one esterase bands were detected and classified as 31 α-esterases, 18 β-esterases and two α/β-esterases. On the basis of the inhibition patterns using Malathion and eserine sulfate, 34 bands were classified as carboxylesterases, 14 as acethylesterases and three as cholinesterases. Ten gene loci were tentatively established on the basis of data on band position in the gel, substrate preference and inhibition pattern. Twenty bands were species-specific, the remaining being shared by species from the same or different subgroups. Bands detected exclusively in males and bands with a different frequency or degree of expression between sexes were also detected. In the gels prepared for analysis of gene expression in the body parts (head, thorax and abdomen), the degree of expression of the β-esterases was higher in the thorax, while the α-esterases were expressed predominantly in the abdomen and thorax. A global view of the data available at present on the esterases of the species from the saltans group and their degree of polymorphism are presented, as well as the possibility of using some β-esterases, because of their characteristics in the gels, as markers for species identification.     

The incidence of mistletoe (<Emphasis Type="Italic">Viscum album</Emphasis> ssp. <Emphasis Type="Italic">abietis</Emphasis>) on silver fir (<Emphasis Type="Italic">Abies alba</Emphasis>) in Croatia

The research on incidence of mistletoe (Viscum album ssp. abietis) on silver fir (Abies alba) was carried out in natural fir stands in Croatia. In the area of Gorski Kotar 32.8 % of the examined dominant fir trees were infected with mistletoe. The mistletoe incidence was presented according to the damage degrees of silver fir from 0 (healthy trees) to 4 (dead trees), rated by the crown defoliation and needle discoloration. With the increase of incidence, mistletoe spreads more onto more vital, i.e. less damaged trees. In the Dinaric Alps 28.6% of the examined fir trees were infected, this percentage amounting to 27.1% for the mountainous regions between the Sava and Drava rivers. The site and stand parameters (exposure, elevation, site quality, forest community and crown closure) were analysed in order to establish whether there was a correlation between these parameters and mistletoe incidence. There was a negative correlation between the elevation and mistletoe incidence. Among the compartments with a closed stands there were considerably less compartments with higher mistletoe incidence than among compartments with a sparsely closed and understocked stands. The other analysed site and stand parameters individually had no significant influence on mistletoe incidence. The correlation of silver fir mortality in 2004 and mistletoe incidence in 2002/03 was analysed, and their strong correlation was established. Mistletoe could be considered as a bioindicator of silver fir decline, and probably a significant contributor to that decline. In the areas where mistletoe incidence is great it can be presumed that silver fir is significantly damaged.     

Structural and physiological responses of two invasive weeds, <Emphasis Type="Italic">Mikania micrantha</Emphasis> and <Emphasis Type="Italic">Chromolaena odorata</Emphasis>, to contrasting light and soil water conditions

To better understand the requirement of light and soil water conditions in the invasion sites of two invasive weeds, Mikania micrantha and Chromolaena odorata, we investigated their structural and physiological traits in response to nine combined treatments of light [full, medium and low irradiance (LI)] and soil water (full, medium and low field water content) conditions in three glasshouses. Under the same light conditions, most variables for both species did not vary significantly among different water treatments. Irrespective of water treatment, both species showed significant decreases in maximum light saturated photosynthetic rate (P _max), photosynthetic nitrogen-use efficiency, and relative growth rate under LI relative to full irradiance; specific leaf area, however, increased significantly from full to LI though leaf area decreased significantly, indicating that limited light availability under extreme shade was the critical factor restricting the growth of both species. Our results also indicated that M. micrantha performed best under a high light and full soil water combination, while C. odorata was more efficient in growth under a high light and medium soil water combination.     

Non-invasive measurement of faecal glucocorticoid metabolites in Upland Geese <Emphasis Type="Italic">Chloephaga</Emphasis><Emphasis Type="Italic">picta</Emphasis>

Glucocorticoid (GC) hormones rise in response to stressors, including natural events including weather or predator presence, and human activities, such as hunting, scientific research or recreational visits. However, because blood sampling itself causes stress and is dangerous or even impossible in some wildlife species, feedback-free methods for GC determination are needed to assess stress in these animals. Faecal GC analyses have thus gained interest. Here, we validate a non-invasive method to estimate the physiological stress in the Upland goose Chloephaga picta. An adrenocorticotropin hormone (ACTH) challenge was conducted in captive adults (female and male), and droppings were collected before, during and after the experiment. Corticosterone metabolite (CM) secretion in response to the ACTH challenge was measured with several enzyme immunoassays (EIA) to find the most appropriate test. We used CM levels during the periods before and after the experiment as control data. An EIA for 11-oxoetiocholanolone achieved the highest response to the ACTH challenge and also reflected a stress response to unfamiliar environment. Furthermore, CM concentrations of dry samples were highly correlated with the corresponding non-dried (frozen) samples. The data suggest that this method is appropriate to measure the stress in Upland geese, and that samples can be stored either frozen or dry form.     

Gynogenesis in the vine cacti <Emphasis Type="Italic">Hylocereus</Emphasis> and <Emphasis Type="Italic">Selenicereus</Emphasis> (Cactaceae)

Gynogenesis was investigated on the allotetraploid Selenicereus megalanthus and the diploid Hylocereus polyrhizus and Hylocereus undatus vine cactus species. Unpollinated ovules from developing flower buds containing microspores at middle uninucleate developmental stage were cultured on MS basal medium containing 2,4-D/TDZ with different sucrose concentrations. Ovule size increased under dark culture conditions in all the three species and the level of response was species and sucrose concentration dependent. The best responses were achieved in the two S. megalanthus accessions, E-123 and J-80, at 0.18 and 0.26 M sucrose. Only ovule enlargement was obtained in H. undatus and both ovule enlargement and callus were obtained in H. polyrhizus. Development in both species ceased and embryoids were not formed. Plant regeneration was directly and indirectly obtained in both S. megalanthus accessions. Ploidy level was determined for a total of 29 S. megalanthus gynogenic plants using flow cytometry: 15 were found to be dihaploid (plants with the gametophytic chromosome number) and the other 14 were found to have higher ploidy levels. This is the first report of successful gynogenesis in Cactaceae. The dihaploids of S. megalanthus successfully produced by ovule culture techniques opens new perspectives in vine cacti breeding.     

Chlorophyll <Emphasis Type="Italic">a</Emphasis> fluorescence induction kinetics in leaves predicted from a model describing each discrete step of excitation energy and electron transfer associated with Photosystem II

Chlorophyll a fluorescence induction (FI) is widely used as a probe for studying photosynthesis. On illumination, fluorescence emission rises from an initial level O to a maximum P through transient steps, termed J and I. FI kinetics reflect the overall performance of photosystem II (PSII). Although FI kinetics are commonly and easily measured, there is a lack of consensus as to what controls the characteristic series of transients, partially because most of the current models of FI focus on subsets of reactions of PSII, but not the whole. Here we present a model of fluorescence induction, which includes all discrete energy and electron transfer steps in and around PSII, avoiding any assumptions about what is critical to obtaining O J I P kinetics. This model successfully simulates the observed kinetics of fluorescence induction including O J I P transients. The fluorescence emission in this model was calculated directly from the amount of excited singlet-state chlorophyll in the core and peripheral antennae of PSII. Electron and energy transfer were simulated by a series of linked differential equations. A variable step numerical integration procedure (ode15s) from MATLAB provided a computationally efficient method of solving these linked equations. This in silico representation of the complete molecular system provides an experimental workbench for testing hypotheses as to the underlying mechanism controlling the O J I P kinetics and fluorescence emission at these points. Simulations based on this model showed that J corresponds to the peak concentrations of Q _A ⁻ Q_B (Q_A and Q_B are the first and second quinone electron acceptor of PSII respectively) and Q _A ⁻ Q _B ⁻ and I to the first shoulder in the increase in concentration of Q _A ⁻ Q _B ²⁻ . The P peak coincides with maximum concentrations of both Q _A ⁻ Q _B ²⁻ and PQH₂. In addition, simulations using this model suggest that different ratios of the peripheral antenna and core antenna lead to differences in fluorescence emission at O without affecting fluorescence emission at J, I and P. An increase in the concentration of Q_B-nonreducing PSII centers leads to higher fluorescence emission at O and correspondingly decreases the variable to maximum fluorescence ratio (F _v/F _m).     

<Emphasis Type="Italic">Cantharellus pseudoformosus</Emphasis>, a new species associated with <Emphasis Type="Italic">Cedrus deodara</Emphasis> from India

The genus Cantharellus is known to have a global distribution and to form ectomycorrhizal associations with a diverse set of host plants. Here we describe Cantharellus pseudoformosus as a species new to science with a possible association with Cedrus deodara. ITS and LSU data demonstrated that the material from India is distinct from Cantharellus formosus and other closely related species.     

Active electrolocation of polarized objects by a pulse-discharging electric fish, <Emphasis Type="Italic">Gnathonemus </Emphasis><Emphasis Type="Italic">petersii</Emphasis>

Weakly electric fish react to resistance and capacitance of objects that locally amplify and distort their self-generated Electric Organ Discharge (EOD) received by their skin receptors. The successive-layer structure of tissues gives certain biological materials a kind of electrical anisotropy. A polarized object, for instance, will conduct current differently in one versus the other direction. This diode-like electric anisotropy should make a significant difference to a Mormyrid who emits a directional, biphasic EOD and whose receptors are sensitive to EOD amplitude and distortion changes. The ability of Gnathonemus petersii (Mormyridae) to discriminate polarity was investigated on a virtual object by manipulating changes in a circuit comprised of diodes combined in various ways. The “novelty response,” an increase in the discharge rate in response to perceived changes, was used to assess the fish’s sensitivity. Indeed, G. petersii detects polarized objects and discriminates between polarity directions. However, the diode-like anisotropy entails a voltage threshold. Because voltage decreases with distance, and the EOD comprises opposite phases of different amplitudes, the active spaces of detection and discrimination are different and depend on the object orientation. Electric polarity thus extends the “palette” of dielectric properties used by this fish to evaluate object quality, direction, and distance.     

Peat-Based Inoculum of <Emphasis Type="Italic">Bradyrhizobium japonicum</Emphasis> and <Emphasis Type="Italic">Sinorhizobium fredii</Emphasis> Supplemented with Xanthan Gum

The addition of xanthan to high water retention capacity peat (HWRC) inoculants did not show differences on the survival of Bradyrhizobium japonicum E109. In low water retention capacity peats (LWRC) however, xanthan increased the survival of B.japonicum significantly. Xanthan showed the best effect at 0.1 g/l for B. japonicum, in contrast to Sinorhizobium fredii USDA205 where the concentrations evaluated (0–1.0 g/l) did not affected significantly its survival. Nevertheless, when the symbiotic performance on soybean was evaluated, the presence of 0.1 g xanthan/l increased the nodule number for both strains.     

Typification of <Emphasis Type="Italic">Metrosideros regelii</Emphasis> (<Emphasis Type="Italic">Myrtaceae</Emphasis>) and consideration of its generic position

Summary  The type specimen of Metrosideros regelii is discussed. It contains a mixture of two species, representing different genera, and a lectotype is chosen. The generic position of the species is considered in the light of morphology and recent molecular evidence and the new combination, Mearnsia regelii, made.     

Isolation of a <Emphasis Type="Italic">Ve</Emphasis> homolog, <Emphasis Type="Italic">mVe1</Emphasis>, and its relationship to verticillium wilt resistance in <Emphasis Type="Italic">Mentha longifolia</Emphasis> (L.) Huds

As a step toward greater understanding of the genetics of verticillium wilt resistance in plants, we report the sequencing of a candidate wilt resistance gene, mVe1, from the mint diploid model species, Mentha longifolia (Lamiaceae). mVe1 is a putative homolog of tomato (Solanum lycopersicum L.) verticillium wilt (Ve) resistance genes. The mVe1 gene has a coding region of 3,051 bp. The predicted mVe1 protein contains a leucine-rich repeat domain, a common feature of plant disease resistance proteins. We compared 13 mVe1 alleles from three mint species. These alleles shared 96.2–99.6% nucleotide identity. We analyzed four M. longifolia populations segregating with respect to mVe1 alleles and wilt resistance versus susceptibility and found one association between mVe1 genotype and wilt phenotype. We conclude that mVe1 may play a role in mint verticillium wilt resistance, but variation for resistance in our segregating progenies is likely polygenic. Therefore, further investigations of mVe1 and identification of additional candidate genes are both warranted.     

Effects of sugars and growth regulators on <Emphasis Type="Italic">in vitro</Emphasis> growth of <Emphasis Type="Italic">Dactylorhiza</Emphasis> species

The influence of sugars and growth regulators on shoot and root growth of Dactylorhiza species was studied under in vitro conditions. The seedling development was stimulated with the application of glucose and sucrose at concentration of 10 g dm⁻³ each. The improvement of shoot growth rate and shoot length was enhanced by cytokinins N ⁶-(2-isopentenyl)adenine or N ⁶-benzyladenine and their combination with auxin indolebutyric acid (IBA). The root growth rate and root length of seedlings increased in the presence of IBA and α-naphthaleneacetic acid. Individual Dactylorhiza species showed statistically significant differences in shoot and root development depending on sugar and growth regulator combinations.     

<Emphasis Type="Italic">In vitro</Emphasis> propagation of ten threatened species of <Emphasis Type="Italic">Mammillaria</Emphasis> (Cactaceae)

Mammillaria species are the most numerous within Cactaceae family, and some of them are threatened with extinction as a result of human activities. In this work, results of in vitro propagation are presented for ten Mammillaria species, testing 20 combinations of indole-3-acetic acid (IAA) and kinetin. Best results on shoot formation were obtained using kinetin at two levels: 27.9 and 46.5 μM. All IAA levels tested were able to induce de novo shoot formation in M. bocasana, M. densispina, M. hahniana, M. hutchisoniana, M. orcutii, M. pectinifera, M. perbella, M. picta, M. rhodantha, and M. zephyranthoides. Depending on the IAA level tested, four responding groups were observed concerning their highest shoot-formation number. For all species, the highest average of shoot formation was achieved with 5.7:46.5 or 11.4:46.5 μM IAA/kinetin, yielding 4.8 and 4.7 shoots per explant, respectively, in 60 d. Rooting of regenerated shoots was achieved by leaving the explants in their shoot-induction medium or transferring them to half-strength MS medium. Hardening of regenerated plants was successfully achieved by planting them in peat moss substrate after a desiccation treatment at room temperature for 3 d.     

Urbanisation induces early flowering: evidence from <Emphasis Type="Italic">Platanus acerifolia</Emphasis> and <Emphasis Type="Italic">Prunus cerasus</Emphasis>

The effect of towns on plant phenology, i.e. advancement of spring development compared with a rural environment, via the urban heat island (UHI) phenomenon, has been shown for many towns in many countries. This work combines experimental and observational methodology to provide a better and deeper view of climatic habitat in an urban context with a view to understanding the relationship between plant development and urban climate on the intra-urban scale (by taking into account town structure). A dense network of 17 meteorological stations was set up in Rennes, France, enabling us to identify and quantify climatic changes associated with the UHI. Meanwhile, phenological observations were made during early spring (March and April) in 2005 on Platanus acerifolia and Prunus cerasus to study the relationship between climatic and phenological data. The results show that there is both a climatic gradient and a developmental gradient corresponding to the type of urbanisation in the town of Rennes. The town influences plant phenology by reducing the diurnal temperature range and by increasing the minimum temperature as one approaches the town centre. The influence of ground cover type (plants or buildings) on development is also shown. The developmental phases of preflowering and flowering are influenced to differing extents by climatic variables. The period during which climatic variables are effective before a given developmental phase varies considerably. The preflowering phases are best correlated with the mean of the minimum air temperature for the 15-day period before the observation, whereas flowering appears to be more dependent on the mean of the daily diurnal temperature range for the 8 days preceding the observation.