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81.
Undamaged plants are known to suffer less damage from herbivores when previously exposed to airborne factors from neighboring plants that are either infested or artificially damaged. However, to date, the effects of such a defensive phenomenon on performance of herbivorous insects have not been clearly shown. Here, we studied such effects in an interaction between a willow plant, Salix eriocarpa Franchet et Savatier (Salicales: Salicaceae), and a specialist leaf beetle, Plagiodera versicolora (Laicharting) (Coleoptera: Chrysomelidae). In a wind tunnel, uninfested willow plants were placed downwind of willow plants infested by leaf beetle larvae for 4 days. As a control, we placed uninfested plants downwind of uninfested plants in the tunnel. After exposure, downwind plants were served to leaf beetle larvae. Pupal weight, larval survival rates, and the leaf area consumed by larvae all decreased significantly, and larval developmental duration increased significantly, when larvae fed on willow plants downwind of infested plants were compared with those downwind of uninfested plants. These results showed that airborne factors from infested willow plants negatively affected the performance of leaf beetle larvae. Further studies are needed to identify the active factor(s) from the infested willow plants affecting the performance of leaf beetle larvae. 相似文献
82.
Soichiro Tabuchi Junji Ito Takashi Adachi Hiroki Ishida Yoji Hata Fumiyoshi Okazaki Tsutomu Tanaka Chiaki Ogino Akihiko Kondo 《Applied microbiology and biotechnology》2010,87(5):1783-1789
A novel cell surface display system in Aspergillus oryzae was established by using a chitin-binding module (CBM) from Saccharomyces cerevisiae as an anchor protein. CBM was fused to the N or C terminus of green fluorescent protein (GFP) and the fusion proteins (GFP-CBM
and CBM-GFP) were expressed using A. oryzae as a host. Western blotting and fluorescence microscopy analysis showed that both GFP-CBM and CBM-GFP were successfully expressed
on the cell surface. In addition, cell surface display of triacylglycerol lipase from A. oryzae (tglA), while retaining its activity, was also successfully demonstrated using CBM as an anchor protein. The activity of
tglA was significantly higher when tglA was fused to the C terminus than N terminus of CBM. Together, these results show that
CBM used as a first anchor protein enables the fusion of both the N and/or C terminus of a target protein. 相似文献
83.
Toshihiro Umebayashi Yasuhiro Utsumi Shinya Koga Susumu Inoue Junji Matsumura Kazuyuki Oda Seizo Fujikawa Keita Arakawa Kyoichi Otsuki 《Trees - Structure and Function》2010,24(3):571-583
A dye injection method was used to elucidate the xylem water-conducting pathways of 34 broadleaved evergreen trees growing
in southern Japan: two semi-ring-porous, 26 diffuse-porous, five radial-porous and one non-vessel species. The large earlywood
vessels in semi-ring-porous species have a water transport function in only the outermost annual ring, as in deciduous ring-porous
species. On the other hand, the small vessels in semi-ring-porous species maintain the water transport function in many outer
annual rings. For the other xylem-type species, the many vessels in many outer annual rings have a water transport function.
In diffuse-porous species, we categorized the water-conducting pattern within the annual rings into two types: d1 type, where
water travels through vessels in the whole region; and d2 type, where water travels mainly through the earlywood vessels.
The pattern in radial-porous species is similar to that in the d1 type; the pattern in non-vessels species is similar to that
in the d2 type. The vessel diameter in radial-porous species is similar to that of the earlywood vessels of semi-ring-porous
species. These results suggest that the conduit diameter size is only one of many factors determining the water-conducting
pathways of broadleaved evergreen species. 相似文献
84.
Rika Ozawa Cinzia M Bertea Maria Foti Ravishankar Narayana Gen-Ichiro Arimura Atsushi Muroi Massimo E Maffei Junji Takabayashi 《Plant signaling & behavior》2010,5(3):308-310
Exogenous polyamines [cadaverine (Cad), putrescine (Put), spermidine (Spd) and spermine (Spm)] elicit the production of volatiles in Lima bean (Phaseolus lunatus). Among the tested PAs, Spm induces the production of some volatile terpenoids that are known to be induced by the spider mite Tetranychus urticae. Spm treatment elicits the biosynthesis of Jasmonic acid (JA), a phytohormone known to regulate the production of the volatile terpenoids. The treatment with JA together with Spm resulted in the increased volatile emission, and predatory mites Phytoseiulus persimilis preferred JA and Spm-treated leaves over those treated with JA alone.5 JA and Spm treatment has no effects on polyamine oxidase (PAO) and Cu-amine oxidase (CuAO) but has a significant induction of calcium influx, ROS production, enzyme activities for NADPH-oxidase complex, superoxide dismutase, catalase, ascorbate peroxidase, glutathione reductase and glutathione peroxidase, and gene expressions except for NADPH-oxidase complex.5 Here, we report that a plasma membrane potential (Vm) depolarization was observed after polyamine perfusion with an increasing trend: Spm, Cad, Put and Spd. JA perfusion did not alter Vm but the perfusion of JA and the polyamines significantly increased Cad and Put Vm depolarization. When JA was perfused with polyamines, a negative correlation was found between Vm depolarization and the number of amino group of the polyamines tested.Key words: polyamines, lima bean, herbivore-induced volatile organic compounds, calcium and ROS signalling, jasmonic acid, quantitative gene expression, transmembrane potentialPolyamines are involved in plants’ stress responses and growth. By activating biosynthesis of nucleic acids, polyamines concern the plant growth and differentiation.1–3 Furthermore, it has been reported that polyamines are involved in the response against environmental stress and plant disease.1–4 We recently reported that exogenously applied polyamines ∼diamines [cadaverine (Cad), putrescine (Put)], triamine [spermidine (Spd)] and tetraamine ]spermine (Spm)]∽ induce volatile emission in Lima bean leaves.5 Membrane potentials (Vm) and intracellular calcium variations were also studied in Lima bean leaves after perfusion with the polyamines and with these addition of JA and here we report on these additional results.The primary candidate for intercellular signaling in higher plants is the stimulus-induced change in Vm.6 The plasma membrane potential (Vm), which lies in the range of −50 to −200 mV in Lima bean leaves,7 may be shifted either to more negative (hyperpolarization) or to more positive values (depolarization) in response to various biotic or abiotic stresses.Measurement of Vm were performed and data statistically treated as previously described (ANOVA and Tukey-Kramer’s HSD test).7 Perfusion with the polyamines (Fig. 1 single arrow) shows a specific response of the leaf tissues with a different Vm depolarization, depending on the polyamine. In general, a Vm depolarization was observed after polyamine perfusion with an increasing trend: Spm, Cad, Put and Spd (Fig. 1). Spm and Spd Vm depolarization values were significantly different (p < 0.05) from all other polyamines, whereas no significant difference was found between Put and Cad Vm depolarization (p = 0.435). In all cases, Vm depolarization was reversed by washing polyamine-treated leaves with a fresh buffer solution (Fig. 1 double arrow); however, a full recovery of the Vm was observed only for Put (Fig. 1). The linearization of the data from Figure 1 allowed to calculate the rate of Vm depolarization after perfusion of the polyamines which was higher for Spd (6.0 mV min−1; R = 0.96), equal for Put and Cad (4.8 mV min−1; Put R = 0.95; Cad R = 0.97) and lower for Spm (3.0 mV min−1; R = 0.96).Open in a separate windowFigure 1Effect of 1 mM polyamines (arrow) on the Vm of Lima bean palisade cells. Spermine (Spm) caused the lowest Vm depolarization, whereas spermidine (Spd) showed the highest values of Vm depolarization. intermediate values were found when putrescine (Put) and cadaverine (cad) were perfused. after washing the tissues with fresh buffer (double arrow) Vm was always hyperpolarized, however the initial potential was recovered only for Put, while for all other polyamines the Vm never reached the initial values. Metric bars indicate standard deviation.Perfusion with JA caused a slight and not significant (p = 0.332) Vm depolarization (Fig. 2) with respect to control. The addition of JA caused a significant increase (p < 0.01) in Vm depolarization when perfused with Cad, with respect to the sole perfusion with Cad (Fig. 1). The same was observed when JA was perfused with Put, whereas not significant differences were observed when Spm (p = 0.513) and Spd (p = 0.107) were perfused with JA (Fig. 2), with respect to the sole perfusion with Spm and Spd (Fig. 1). The linearization of the data from Figure 2 allowed to calculate the rate of Vm depolarization after perfusion of the polyamines + JA, which was higher for Cad (24.40 mV min−1; R = 0.99), almost equal for Put and Spd (Put: 14.21 mV min−1, R = 0.99; Spd: 13.49 mV min−1, R = 0.99) and lower for Spm (1.34 mV min−1; R = 0.93). For JA the rate of Vm depolarization was 0.19 mV min−1 (R = 0.96). With the addition of JA, a negative correlation was found between Vm depolarization and the number of amino group of the polyamines tested.Open in a separate windowFigure 2Effect of 1 mM polyamines + 0.1 mMJA (arrow) on the Vm of Lima bean palisade cells. the perfusion with Ja did not cause any variation in the Vm. addition of JA to Spm and Spd caused the same Vm depolarization observed in the absence of JA, whereas when JA was added to Put and Cad a stronger and significantly different Vm depolarization was observed. even in this case washing the tissues with fresh buffer (double arrow) caused a Vm hyperpolarized, however in this case Spd reached Vm values significantly more negative that the initial Vm. Metric bars indicate standard deviation. For abbreviations see Figure 1.Since ion fluxes through channels directly influence Vm, it seems reasonable to assume that molecules able to act on channel activity might be considered as important factors inducing electrical signals. Among the various channels, calcium and potassium channels are predominantly involved in cell signaling.8 In the present study, rapid and reversible Vm depolarization observed upon perfusion of Lima bean mesophyll cells with polyamines was found to be significantly increased when JA was added to Cad and Put. The reversibility of the Vm may be linked to the overall physico-chemical amphiphilic properties of polyamines, probably depending on non covalent interaction with plasma membrane molecules, as polyamines occur in plants in free form, bound electrostatically to negatively charged molecules, and conjugated to small molecules and proteins.9 Liu et al.10 showed that Spm, Spd, Cad and Put strongly inhibited opening and closing of stomata in Vicia faba, suggesting that polyamines target inward potassium channels in guard cells and modulate stomatal movements, so providing a link between abiotic stress, polyamine levels and stomatal regulation. Moreover, the transport of polyamines across the plasma membrane of plant cells is energy-dependent and calcium is involved in the uptake mechanism.1,11 Both mechanisms can be correlated to the observed Vm depolarization, and the positive correlation between intracellular Ca2+ concentration5 and Vm depolarizing activity of polyamines confirms the involvement of Ca2+ during polyamine uptake.11 相似文献
85.
Junichi Matsubara Masaya Ono Kazufumi Honda Ayako Negishi Hideki Ueno Takuji Okusaka Junji Furuse Koh Furuta Emiko Sugiyama Yoshiro Saito Nahoko Kaniwa Junichi Sawada Ayako Shoji Tomohiro Sakuma Tsutomu Chiba Nagahiro Saijo Setsuo Hirohashi Tesshi Yamada 《Molecular & cellular proteomics : MCP》2010,9(4):695-704
86.
Inoue Y Nomura W Takeuchi Y Ohdate T Tamasu S Kitaoka A Kiyokawa Y Masutani H Murata K Wakai Y Izawa S Yodoi J 《Applied and environmental microbiology》2007,73(5):1672-1675
Thioredoxin, an antioxidant protein, is a promising molecule for development of functional foods because it protects the gastric mucosa and reduces the allergenicity of allergens. To establish a method for obtaining an ample amount of yeast thioredoxin, we found here that thioredoxin is released from Saccharomyces cerevisiae by treatment with 20% ethanol. We also found that Japanese sake contains a considerable amount of thioredoxin. 相似文献
87.
Yui T Taki N Sugiyama J Hayashi S 《International journal of biological macromolecules》2007,40(4):336-344
An exhaustive search of the crystal structure of beta-chitin was carried out by simultaneously optimizing all the structural parameters based on published X-ray diffraction data and stereochemical criteria. The most probable structure was characterized by a parallel-up chain polarity, a gg orientation of hydroxymethyl groups and an intermolecular hydrogen bond along the a-axis, which essentially reproduced the original structure proposed by Gardner and Blackwell. The proposed crystal structure was subsequently subjected to crystal modeling using the AMBER force field. The probable orientation of hydroxyl groups and their motional behaviors is proposed based on calculations for the crystal models identified. Solvated crystal models exhibited a slightly deformed structure with the formation of appreciable numbers of hydrogen bonds along the b-axis. 相似文献
88.
We carried out a theoretical investigation of whether ecological character displacement can be caused by reproductive interference. Our model assumes that a quantitative character is associated with both resource use and species recognition, and that heterospecific mating incurs costs. The model shows that ecological character displacement can occur as a consequence of evolution of premating isolation; this conclusion is based on the premise that resource competition is less intense between species than within species and that the ecological character also contributes to premating isolation. When resource competition between species is intense, extinction of either species may occur by competitive exclusion before ecological character divergence. Some observational studies have shown that character displacement in body size is associated with not only resources use but also species recognition. We propose that body size displacement can occur as a consequence of evolution of premating isolation. Our results suggest that ecological character displacement results from reproductive character displacement. 相似文献
89.
90.
We explored how functional trade-offs in resource handling strategies are associated with the divergent morphology of predators. The malacophagous carabid Damaster blaptoides shows two extreme morphologies in the forebody; there is an elongate small-headed type and a stout large-headed type. A feeding experiment showed that the small-headed type obtained a high feeding performance on snails with a thick shell and a large aperture by penetrating the shell with its head. In contrast, the large-headed type showed a high feeding performance on snails that had a thin shell and a small aperture, and they ate these prey by crushing the shell. The large-headed, strong-jawed beetles are efficient at shell crushing but are ineffective at shell entry; the large mandibles and musculature that allow for shell crushing make the beetle's head too wide to penetrate shell apertures. On the other hand, small-headed, weak-jawed beetles crush poorly but can reach into shells for direct predation on snail bodies. These findings are hypothesized to be functional trade-offs between force and fit due to morphological constraints. This trade-off would be a primary mechanism affecting both resource handling ability in animals and phenotypic diversity in predators and prey. 相似文献