Earthen Structures Built by Ilyoplax dentimerosa (Crustacea,Brachyura, Ocypodidae)

Under observation, the small ocypodid crab Ilyoplax dentimerosa was found to commonly build three types of earthen structures: a barricade near its neighbour's burrow, a fence at an intermediate position between the burrows of the builder and its neighbour, and a minishelter near the builder's burrow. The sex ratio of barricade builders was found to be close to 1:1, whereas most of the fence builders were found to be female. Crabs against which barricades and fences were built, were usually smaller than the builders. Both barricade builders and fence builders had, in most cases, minishelters at the side, facing the barricade or the fence. Removal and rebuilding experiments for barricades and fences demonstrated that both structures functioned to deter the approach of the builder's neighbour to the builder's activity site. Fences also had the effect of restraining the movement of the builder toward the fence site.     

Relationships between foliar carbon isotope discrimination with potassium concentration and ash content of the riparian plants in the extreme arid region of China

Carbon isotope discrimination (Δ) has been proposed as an indirect estimation criterion for water use efficiency in C₃ plants. Because of the higher cost for Δ analysis, ash content or K concentration has been proposed as an alternative criterion for Δ in many species. In five typical habitats of the extreme arid Ejina desert oasis in northwest of China, the seasonal variations of foliar δ, ash content, and potassium (K) concentration were researched in two constructive desert riparian plants (Populus euphratica Olivier, Tamarix ramosissima Ledeb). The correlations of foliar Δ with ash content and K concentration in both species were also examined to evaluate the feasibility of the foliar ash content and K concentration as surrogates of Δ in P. euphratica and T. ramosissima. Results showed that there were significant effects of plant species, habitats and growth season on foliar Δ, ash content, and K concentration. Foliar Δ and K concentration in P. euphratica were significantly higher than those in T. ramosissima, whereas, the ash content was reverse. Among habitats, the trends of δ signatures in both P. euphratica and T. ramosissima were similar, δ values and ash content in both species were the lowest in the dune. Both in the Gobi and dune sites, K concentration in P. euphratica and T. ramosissima was different. In the whole growth period, foliar Δ values and ash content in both species were gradually increased, but K concentration was decreased. Ash content was significantly and positively related to δ in both P. euphratica and T. ramosissima. However, significantly negative correlations between foliar δ and K concentration as well as between ash content and K in P. euphratica were found. In T. ramosissima, the relationship was positive but very weak.     

Spermidine levels are implicated in heavy metal tolerance in a <Emphasis Type="Italic">spermidine synthase</Emphasis> overexpressing transgenic European pear by exerting antioxidant activities

To verify whether spermidine synthase (SPDS) can confer long-term multi-heavy metal tolerance, in vitro shoots of a transgenic European pear (Pyrus communis L. ‘Ballad’) line #32 overexpressing apple SPDS (MdSPDS1), as well as a wild type (WT) line, were subjected to stress using either CdCl₂, PbCl₂, ZnCl₂, or a combination thereof. Based on either shoot height increment or fresh weight and morphological changes upon heavy metal stress, the performance of the transgenic line #32 was better than that of WT. Although SPDS expression levels and spermidine (Spd) contents in line #32 were higher than those in WT, possibly due to transgene (MdSPDS1) expression, no obvious inductions of SPDS expression and increases in Spd-content were observed by long-term stress treatments in both lines. When the glutathione (GSH) content was compared with or without stress in each line, GSH was significantly depleted in line #32 with stress, but not as much as in WT. The activities of glutathione reductase and superoxide dismutase and the content of malondialdehyde, an indicator for lipid peroxidation, changed upon stress toward a more favorable status for survival in line #32 than in WT. These antioxidant parameters were positively related to Spd-content. The accumulation of heavy metals tended to be less in line #32 than in WT except for Zn stress, and the Ca content showed an opposite trend. These results suggest that Spd-levels are implicated in enhanced heavy metal tolerance, possibly by exerting an antioxidant activity as well as by the properties of Spd per se including metal chelator.     

Wild edible plants of the Sikkim Himalaya: Nutritive values of selected species

Wild edible plants form an important constituent of traditional diets in the Himalaya. In the Sikkim Himalaya a total of 190 species have been screened as edible species out of which nearly 47 species come to the market. The present paper deals with nutritive values of 27 most commonly consumed wild edible plants in the Sikkim Himalaya. Of 27 plant species that were analyzed for their nutritive values, 22 were edible for their fruits and five for leaves/shoots. Among different plant parts, generally higher nutrient concentration was recorded for leaves, followed by new shoots and fruits. For different species the crude fiber content ranged between 2.15–39.90%, and the total soluble salts between 4.66–21.00%, and the vitamin C content from 6–286 mg/100 g. The fat content was determined high in the fruits ofCastanopsis hystrix, Machilus edulis, andCinnamomum species, while the protein content was highest inHippophae rhamnoides, Cucumis melo, andEleagnus latifolia. The total carbohydrate content ranged from 32–88% in the fruits of various wild edibles, the reducing sugar from 1.25–12.42%, total sugar from 2.10–25.09%, the lignin content varied from 9.05–39.51%, the hemicellulose between 25.63–55.71% and cellulose content varied from 9.57–33.19% in different species. Among the various macronutrients estimated in the plant samples of different wild edible species, nitrogen was present in highest quantity, followed by potassium, calcium, magnesium, phosphorus, and sodium. Micronutrients, such as iron, zinc, magnesium, and copper contents were analyzed in different plant parts of various wild edible species. The iron content was higher in leaves and new shoots. The nutritive values of certain wild edible species determined in this study are comparable with various commercial fruits. It is suggested that a few wild edible species need to be grown for commercial cultivation and adopted in the traditional agroforestry systems, which will lead to reduced pressure on them in natural forest stands as well as producing economic benefits for poor farmers.     

The effect of salicylic acid on barley response to water deficit

The effect of a moderate (PEG −0.75 MPa) and severe (PEG −1.5 MPa) water deficit on SA content in leaves and roots as well as the effect of pre-treatment with SA on reaction to water stress were evaluated in two barley genotypes — the modern cv. Maresi and a wild form of Hordeum spontaneum. Water deficit increased SA content in roots, whereas SA content in leaves did not change. The level of SA in the roots of control plants was about twofold higher in ‘Maresi’ than in H. spontaneum. After 6 hours of a moderate stress the level of SA increased about twofold in H. spontaneum and about two and a half-fold in ‘Maresi’. Under severe stress conditions the level of SA increased about twofold in the both genotypes, but not before 24 hrs of the stress. Plant treatment with SA before stress reduced a damaging action of water deficit on cell membrane in leaves. A protective effect was more noticeable in H. spontaneum than in ‘Maresi’. SA treatment increased ABA content in the leaves of the studied genotypes. An increase of proline level was observed only in H. spontaneum. The obtained results suggest that ABA and proline can contribute to the development of antistress reactions induced by SA.     

Chlorophyll content and leaf elongation rate in wheat seedlings as a measure of manganese tolerance

After aluminum toxicity, manganese (Mn) toxicity is probably the second most important growth limiting factor in acid soils. The purpose of this study was to determine the feasibility of using chlorophyll content and leaf elongation rate (LER) for regrowth of Mn stressed seedlings as a rapid seedling based screening bioassay for Mn tolerance in segregating populations of wheat (Triticum aestivum L.). In one experiment, chlorophyll was determined for the cultivars Norquay (Mn-tolerant) and Columbus (Mn-sensitive) subjected to twelve Mn levels (2 to 2000 μM) in nutrient solutions. As Mn concentration increased, chlorophyll ‘a’ and ‘b’ contents of the Mn-tolerant cultivar decreased up to 9%, while in the Mn-sensitive cultivar it was reduced by as much as 43%. The chlorophyll ‘a/b’ ratio did not differ among Mn concentrations for either cultivar. In a second experiment, chlorophyll content and LER for regrowth of Mn stressed seedlings (1000 μM) was determined for Columbus and Katepwa (Mn-sensitive), Oslo (Mn-intermediate), and Norquay and Laura (Mn-tolerant). Manganese tolerance as assayed by chlorophyll ‘a’ and ‘b’ and LER was significantly correlated with Mn tolerance as assayed by the relative root weight methodology (RRW). Thus, chlorophyll content of Mn-stressed seedlings and LER of seedling regrowth appear to be suitable techniques for screening unreplicated selections of segregating populations for tolerance to Mn.     

Water-soluble substances in meristems of buds of <Emphasis Type="Italic">Picea obovata</Emphasis> L. and <Emphasis Type="Italic">Pinus sylvestris</Emphasis> L.: Concentrations,composition, and properties during the development of freezing tolerance

The seasonal dynamics of water-soluble substances and water content in the meristematic tissues of vegetative buds of Picea obovata L. and Pinus sylvestris L. are considered. Changes in the concentrations of the cytoplasmic solutions of meristematic cells under their dehydration as a result of extracellular or extraorgan freezing were determined. It was found that the concentration of water-soluble substances of the cytoplasm can increase by a factor of 2–2.5 as the below-zero temperature decreases to −40 °C due to water crystallization. A relationship was found between the cellular content of crystallizable water, nonfreezing water, and the concentration of water-soluble substances with a decrease in temperature from 0 to −40 °C.     

David Graeber's Wunderkammer,Debt: The First 5 000 Years

Graeber’s Debt: The First 5 000 Years has generated extensive commentary in the popular press and has captured the imagination of both activists at the barricades and investment fund managers in the City of London. Everyone is captivated by his critique of the myth of primitive barter. Yet it is a puzzle that a core element of his argument—the myth of primordial debt—has been largely overlooked. This review seeks to redress this oversight and in the process to suggest that Graeber’s emphasis on violence and enslavement, while compelling, is limited by his quest for origins. Feminist anthropology taught us to set aside the question, ‘when did “it” begin’ and instead open up to other questions, beyond the limits and biases the quest for origins presupposes. One wishes Graeber had entered the wonder cabinet he constructed in this book, rather than use it to ground a teleology.     

Effect of phenylalanine and phenylpropanoids on the accumulation of capsaicinoids and lignin in cell cultures of chili pepper (<Emphasis Type="Italic">capsicum annuum</Emphasis> L.)

Summary Chili pepper (Capsicum annuum L., cv. Tampique?o 74) cell suspensions were employed to study the influence of phenylalanine and phenylpropanoids on the total production of capsaicinoids, the hot taste compounds of chili pepper fruits. The effect of capsaicinoid precursors and intermediates on the accumulation of lignin as an indicator of metabolic diversion was also investigated. Addition of 100 μM of either phenylalanine, cinnamic or caffeic acids to chili pepper cell cultures did not cause significant increases in total capsaicinoids (expressed as capsaicin content, and calculated as averages of the measured values) during the growth cycle. The highest total capsaicinoid content was recorded in cultures grown in the presence of vanillin (142.61 μg g⁻¹ f.wt.), followed by cells treated with 100 μM vanillylamine (104.88 μg g⁻¹ f.wt.), p-coumaric acid (72.36 μg g⁻¹ f.wt.). and ferulic acid (34.67 μg g⁻¹ f.wt.). Capsaicinoid content for control cells was 13.97 μg g⁻¹ f.wt. Chili pepper cell suspensions cultured in the presence of 100 μM of either phenylalanine, or cinnamic, caffeic, or ferulic acids, or the same concentration, of vanillin and vanillylamine, did not exhibit statistically significant differences in the content of lignin as compared with control cells. However, addition of p-coumaric acid (100 μM) to the cultute medium significantly increased thelignin production (c. 10–15 times the contents of control cells).     

Effect of dikegulac on growth and alkaloid production inCatharanthus roseus (L.) G. Don. (pink flowered)

Application of sodium-dikegulac reduced plant height with associated increase in branch and leaf number and root biomass inC. roseus (L.) G. DON. Chlorophyll content reduced significantly after first month of 100 and 250 μg/ml DK application. However, such reduction was replaced by significant rise after forth month in 250 μg/ml DK application and fifth month in 100 μg/ml DK application followed by appreciable decline only in 250 μg/ml DK treatment but 100 μg/ml DK maintained higher level till harvest. Total sugar content was significantly high during forth and fifth month stage of growth after DK application. Amino acid content was higher during third to fifth month in 100 μg/ml DK treatment and during third to forth month in 250 μg/ml DK treatment. Tryptophan, on the other hand showed higher content at the fifth month stage of growth after application of DK in both the concentrations. Leaf and root dry weight as well as total alkaloid content were highest in 100 μg/ml DK application. DK, therefore, appears to be a potential chemical for increasing biomass and alkaloid content inC. roseus.     

Effects of AM colonization on “wild tobacco” plants grown in zinc-contaminated soil

This greenhouse study aimed to determine the effect of colonization by the arbuscular mycorrhizal (AM) fungus (Glomus intraradices Schenck & Smith) on the “wild” tobacco (Nicotiana rustica L. var. Azteca), under soil–zinc (Zn) conditions. Plants of N. rustica were grown in AM or non-AM inoculated substrate and subjected to four soil–[Zn] concentrations (0, 50, 100, and 250 mg Zn kg⁻¹ dry soil). The AM root colonization increased markedly from 14 to 81% with the increasing soil–[Zn] and the mycorrhizal structures were significantly more abundant at the highest soil–[Zn], suggesting that Zn may be involved directly or indirectly in AM root colonization. In addition, total Zn content or Zn concentrations in shoots and roots were shown to increase as soil–[Zn] increased in both AM and non-AM plants. As for the growth parameters studied, there were no significant differences between treatments despite the increase in Zn content or concentration. The AM roots subjected to the highest soil–[Zn] had a significant reduction by about 50% of total Zn content and Zn concentration compared to non-AM roots. Still, the relative extracted Zn percentage decreased dramatically as soil–[Zn] increased. Soil pH was significantly lower in non-AM than AM treatments at the highest soil–[Zn]. In summary, AM plants (particularly roots) showed lower Zn content and concentration than non-AM plants. In this regard, the AM fungi have a protective role for the host plant, thus playing an important role in soil-contaminant immobilization processes; and, therefore, are of value in phytoremediation, especially when heavy metals approach toxic levels in the soil.     

Bacterial alginates: biosynthesis and applications

Alginate is a copolymer of β-d-mannuronic acid and α-l-guluronic acid (GulA), linked together by 1–4 linkages. The polymer is a well-established industrial product obtained commercially by harvesting brown seaweeds. Some bacteria, mostly derived from the genus Pseudomonas and belonging to the RNA superfamily I, are also capable of producing copious amounts of this polymer as an exopolysaccharide. The molecular genetics, regulation and biochemistry of alginate biosynthesis have been particularly well characterized in the opportunistic human pathogen Pseudomonas aeruginosa, although the biochemistry of the polymerization process is still poorly understood. In the last 3 years major aspects of the molecular genetics of alginate biosynthesis in Azotobacter vinelandii have also been reported. In both organisms the immediate precursor of polymerization is GDP-mannuronic acid, and the sugar residues in this compound are polymerized into mannuronan. This uniform polymer is then further modified by acetylation at positions O-2 and/or O-3 and by epimerization of some of the residues, leading to a variable content of acetyl groups and GulA residues. In contrast, seaweed alginates are not acetylated. The nature of the epimerization steps are more complex in A. vinelandii than in P. aeruginosa, while other aspects of the biochemistry and genetics of alginate biosynthesis appear to be similar. The GulA residue content and distribution strongly affect the physicochemical properties of alginates, and the epimerization process is therefore of great interest from an applied point of view. This article presents a survey of our current knowledge of the molecular genetics and biochemistry of bacterial alginate biosynthesis, as well as of the biotechnological potential of such polymers. Received: 14 March 1997 / Received revision: 7 May 1997 / Accepted: 11 May 1997     

Construction and characterization of the hetero-oligomer of the group II chaperonin from the hyperthermophilic archaeon, Thermococcus sp. strain KS-1

The hyperthermophilic archaeon Thermococcus sp. strain KS-1 (T. KS-1) expresses two different chaperonin subunits, α and β, for the folding of its proteins. The composition of the subunits in the hexadecameric double ring changes with temperature. The content of the β subunit significantly increases according to the increase in temperature. The homo-oligomer of the β subunit, Cpnβ, is more thermostable than that of the α subunit, Cpnα. Since Cpnα and Cpnβ also have different protein folding activities and interactions with prefoldin, the hetero-oligomer is thought to exhibit different characteristics according to the content of subunits. The hetero-oligomer of the T. KS-1 chaperonin has not been studied, however, because the α and β subunits form hetero-oligomers of varying compositions when they are expressed simultaneously. In this study, we characterized the T. KS-1 chaperonin hetero-oligomer, Cpnαβ, containing both α and β in the alternate order, which was constructed by the expression of α and β subunits in a coordinated fashion and protease digestion. Cpnαβ protected citrate synthase from thermal aggregation, promoted the folding of acid-denatured GFP in an ATP-dependent manner, and exhibited an ATP-dependent conformational change. The yield of refolded GFP generated by Cpnαβ was almost equivalent to that generated by Cpnβ but lower than that generated by Cpnα. In contrast, Cpnαβ exhibited almost the same level of thermal stability as Cpnα, which was lower than that of Cpnβ. The affinity of Cpnαβ to prefoldin was found to be between those of Cpnα and Cpnβ, as expected.     

Seed specific expression of perilla γ-tocopherol methyltransferase gene increases α-tocopherol content in transgenic perilla (<Emphasis Type="Italic">Perilla frutescens</Emphasis>)

Increasing vitamin E activity in economically important oil crops such as perilla will enhance the nutritional value of these crops. Perilla (Perilla frutescens Britt) represents an important oil crop in Asian countries, including Korea. Using Agrobacterium-mediated transformation, we have engineered perilla with the γ-tocopherol methyltransferase (γ-TMT) gene under the control of seed-specific vicillin promoter. Molecular characterization including PCR, Southern and Northern blots confirmed that the γ-TMT transgene was successfully inherited to and expressed in the progeny plants. The γ -TMT transgene was specifically expressed in immature seeds of transgenic plants, leading to efficient conversion of γ-tocopherol to α-tocopherol and dramatic increase in seed α-tocopherol content, as detected by high performance liquid chromatography analysis. We also showed that such a high α-tocopherol content phenotype was transmitted to the progeny plants. In addition, there was no significant change in fatty acid composition in transgenic seeds as compared with untransformed control Yeupsil cultivar, suggesting the lack of interplay between the fatty acid and tocopherol biosynthesis pathways. This was the first report on over expression of the γ-TMT gene in transgenic perilla displaying desirable high α-tocopherol content phenotype. Since α-tocopherol has the highest vitamin E activity, the transgenic perilla with high α-tocopherol content in seeds developed in this study will benefit both human and animal health.     

Stress-Induced Changes in Optical Properties,Pigment and Fatty Acid Content of <Emphasis Type="Italic">Nannochloropsis</Emphasis> sp.: Implications for Non-destructive Assay of Total Fatty Acids

In order to develop a practical approach for fast and non-destructive assay of total fatty acid (TFA) and pigments in the biomass of the marine microalga Nannochloropsis sp. changes in TFA, chlorophyll, and carotenoid contents were monitored in parallel with the cell suspension absorbance. The experiments were conducted with the cultures grown under normal (complete nutrient f/2 medium at 75 μmol PAR photons/(m² s)) or stressful (nitrogen-lacking media at 350 μmol PAR photons/(m² s)) conditions. The reliable measurement of the cell suspension absorbance using a spectrophotometer without integrating sphere was achieved by deposition of cells on glass–fiber filters in the chlorophyll content range of 3–13 mg/L. Under stressful conditions, a 30–50% decline in biomass and chlorophyll, retention of carotenoids and a build-up of TFA (15–45 % of dry weight) were recorded. Spectral regions sensitive to widely ranging changes in carotenoid-to-chlorophyll ratio and correlated changes of TFA content were revealed. Employing the tight inter-correlation of stress-induced changes in lipid metabolism and rearrangement of the pigment apparatus, the spectral indices were constructed for non-destructive assessment of carotenoid-to-chlorophyll ratio (range 0.3–0.6; root mean square error (RMSE) = 0.03; r ² = 0.93) as well as TFA content of Nannochloropsis sp. biomass (range 5.0–45%; RMSE = 3.23 %; r ² = 0.89) in the broad band 400–550 nm normalized to that in chlorophyll absorption band (centered at 678 nm). The findings are discussed in the context of real-time monitoring of the TFA accumulation by Nannochloropsis cultures under stressful conditions.     

Biosynthesis of ω-alicyclic fatty acids induced by cyclic precursors and change of membrane fluidity in thermophilic bacteria <Emphasis Type="Italic">Geobacillus stearothermophilus</Emphasis> and <Emphasis Type="Italic">Meiothermus</Emphasis><Emphasis Type="Italic">ruber</Emphasis>

Two thermophilic strains belonging to Geobacillus stearothermophilus and Meiothermus ruber, which naturally do not synthesize ω-alicyclic fatty acids (ω-FAs) were cultivated with cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl carboxylic acids. Gas chromatography–mass spectrometry analysis of fatty acid methyl and picolinyl esters showed that both strains are able to synthesize ω-FAs when cultivated with the appropriate precursor. The incorporation of cyclic acids influenced the whole FA composition as well as membrane fluidity. Membrane fluidity of intact cells was studied by measuring the fluorescence polarisation of the probe l,6-diphenyl-1,3,5-hexatriene incorporated into membrane lipid bilayers. Cytoplasmic membrane became more fluid with increasing content of ω-FAs. This is caused by considerable changes in lipid packing within the membrane induced by the presence of ω-FAs not found in the natural environment of Geobacillus and Meiothermus strains.     

Growth regulator-induced betacyanin accumulation and dopa-4,5-dioxygenase (<Emphasis Type="Italic">DODA</Emphasis>) gene expression in euhalophyte <Emphasis Type="Italic">Suaeda salsa</Emphasis> calli

Suaeda salsa calluses cultured in darkness for 28 d were transferred to Murashige and Skoog (MS) media containing various growth regulators under white light conditions for 10 d to investigate cell growth, betacyanin accumulation, and expression of dopa-4,5-dioxygenase (DODA). Callus growth was markedly promoted when 0.2 mg·L⁻¹ 2,4-D and 0.5 mg·L⁻¹ 6-BA were added to the MS medium. Surprisingly, of the auxins tested, IAA had no effect on betacyanin content, but 2,4-D strongly decreased betacyanin content. Betacyanin content was positively correlated with 6-BA concentrations in the range of 0.1–2.0 mg·L⁻¹. DODA mRNA levels were consistent with the response of betacyanin content to exogenous growth regulators. These results suggest that betacyanin metabolism in S. salsa calluses is regulated under white light conditions by growth regulators through the regulation of genes such as DODA that are involved in betacyanin synthesis.     

Regulation of Carotenoid Content in Tomato by Silencing of Lycopene β/ε-Cyclase Genes

To conduct RNAi interference of Lyc-β and Lyc-ε genes, two plant expression vectors were constructed by inserting the intron fragments of the gusA gene into the two target gene fragments, which were designed in anti-sense directions. After the Agrobacterium tumefaciens-mediated transformation, 13 transgenic tomato plants (seven and six for Lyc-β and Lyc-ε, respectively) were obtained, which was further validated by PCR. Real-time PCR revealed that the messenger RNA abundance of Lyc-β gene and Lyc-ε gene in transgenic tomato plants was significantly reduced to 8.95% and 13.16%, respectively, of the level of the wild-type plant. Subsequent high-performance liquid chromatography analysis found that transgenic tomato plant had significantly increased lycopene content, with the highest value of 13.8 μg/g leaf dry weight, which was about 4.2-fold that of wild-type plant. Moreover, Lyc-β and Lyc-ε interference gene effects were observed on downstream products as well. β-Carotene and lutein contents decreased in Lyc-β RNAi lines, ranging from 40.7 to 117.3 μg/g and 4.9 to 23.5 μg/g leaf dry weight, respectively. In Lyc-ε RNAi lines, β-carotene content increased, ranging from 195.8 to 290.2 μg/g, while lutein content decreased, ranging from 3.7 to 11.3 μg/g. For total carotenoids, Lyc-β RNAi lines resulted in 2.9-fold decrease, while Lyc-ε RNAi lines yielded 1.7-fold increase in contents when compared to wild-type control. This study demonstrated that RNAi gene technology is an effective method for enhancing lycopene content in plants.