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21.
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
22.
Pedroso RS Lavrador MA Ferreira JC Candido RC Maffei CM 《Memórias do Instituto Oswaldo Cruz》2010,105(8):993-1000
The pathogenicity of Cryptococcus neoformans is heterogeneous and is associated with the expression of virulence factors. This study aimed to correlate the pathogenicity of C. neoformans var. grubii in BALB/c mice with in vitro virulence factors, fluconazole minimal inhibitory concentrations (MICs) and molecular profiles, before and after animal passage. Ten environmental isolates and one ATCC strain of C. neoformans var. grubii mating type α were evaluated. Most isolates (91%) killed 50% or more of the infected animals by day 24 postinfection and were recovered from the lungs and brains of surviving animals on days 7 and 14 postinfection. The burden of yeast in the lungs was more variable than that in the brain. The differences in the expression of virulence factors (growth at 37oC, presence and size of the capsule and production of melanin, urease, proteinase and phospholipase) by most isolates pre and postpassage in animals were not statistically significant. The fluconazole MICs in postpassaged lines differed by a one-dilution from the MIC of the corresponding prepassaged line for six isolates. Using molecular typing [polymerase chain reaction-fingerprinting with (GACA)4 and M13], eight isolates were identified as VNI and three as VNII. We concluded that different isolates with the same molecular and phenotypic profiles, including isolates that are markedly hypervirulent, span a wide range of virulence and there were no changes in virulence factors in the postpassaged lines when compared with the corresponding nonpassaged lines. 相似文献
23.
Gen-ichiro Arimura Massimo E. Maffei 《Biochemical and biophysical research communications》2010,400(4):455-460
Plant Ca2+ signals are involved in a sizable array of intracellular signaling pathways after pest invasion. Upon herbivore feeding there is a dramatic Ca2+ influx, followed by the activation of Ca2+-dependent signal transduction pathways that include interacting downstream networks of kinases for defense responses. Notably, Ca2+-binding sensory proteins such as Ca2+-dependent protein kinases (CPKs) have recently been documented to mediate the signaling following Ca2+ influx after herbivory, in phytohormone-independent manners. Here, we review the sequence of signal transductions triggered by herbivory-evoked Ca2+ signaling leading to CPK actions for defense responses, and discuss in a comparative way the involvement of CPKs in the signal transduction of a variety of other biotic and abiotic stresses. 相似文献
24.
Melek Güler-Yüksel Naomi B Klarenbeek Yvonne PM Goekoop-Ruiterman Jeska K de Vries-Bouwstra Sjoerd M van der Kooij Andreas H Gerards H Karel Ronday Tom WJ Huizinga Ben AC Dijkmans Cornelia F Allaart Willem F Lems 《Arthritis research & therapy》2010,12(3):R96
Introduction
To investigate whether accelerated hand bone mineral density (BMD) loss is associated with progressive joint damage in hands and feet in the first year of rheumatoid arthritis (RA) and whether it is an independent predictor of subsequent progressive total joint damage after 4 years.Methods
In 256 recent-onset RA patients, baseline and 1-year hand BMD was measured in metacarpals 2-4 by digital X-ray radiogrammetry. Joint damage in hands and feet were scored in random order according to the Sharp-van der Heijde method at baseline and yearly up to 4 years.Results
68% of the patients had accelerated hand BMD loss (>-0.003 g/cm2) in the first year of RA. Hand BMD loss was associated with progressive joint damage after 1 year both in hands and feet with odds ratios (OR) (95% confidence intervals [CI]) of 5.3 (1.3-20.9) and 3.1 (1.0-9.7). In univariate analysis, hand BMD loss in the first year was a predictor of subsequent progressive total joint damage after 4 years with an OR (95% CI) of 3.1 (1.3-7.6). Multivariate analysis showed that only progressive joint damage in the first year and anti-citrullinated protein antibody positivity were independent predictors of long-term progressive joint damage.Conclusions
In the first year of RA, accelerated hand BMD loss is associated with progressive joint damage in both hands and feet. Hand BMD loss in the first year of recent-onset RA predicts subsequent progressive total joint damage, however not independent of progressive joint damage in the first year. 相似文献25.
Discrimination of truffle fruiting body versus mycelial aromas by stir bar sorptive extraction 总被引:3,自引:0,他引:3
Stir bar sorptive extraction (SBSE) was applied in head space mode (HS), coupled with GC/MS, to compare the aroma profile of three truffle species. A total of 119 volatile organic compounds (VOCs) were identified from the fruiting bodies, of which 70 were not yet described in truffles and 60 in fungi. VOCs profile showed a high intra- and inter-specific variability, with alcohols and sulfur compounds dominating the HS of Tuber borchii and, alcohols, aldehydes and aromatic compounds the HS of T. melanosporum and T. indicum. Despite these variations, eight VOCs markers could be identified allowing the discrimination of the three species. Additionally, T. borchii and T. melanosporum both distinguished themselves from T. indicum due to higher aroma content and larger variety of sulfur containing compounds. Mycelial VOCs production was also investigated under two cultural conditions and led to the identification of eight VOCs. On one side, seven of them were also detected in the fruiting body, confirming their mycelial origin. On the other side, the total absence of some class of compounds (i.e. sulfur) in the mycelium raises questions about their origins in the fruiting bodies and confirms deep metabolic changes between the reproductive (fruiting body) and vegetative (mycelium) stages. 相似文献
26.
Before gene expression: early events in plant-insect interaction 总被引:4,自引:0,他引:4
Successful defense depends on the ability of the plant to recognize an attacking 'enemy' as early as possible. Early defense responses require enemy-initiated signaling cascades. Their activation ensures an induced response that is quantitative, timely and coordinated with other activities of the host cells. Damage-induced ion imbalances and modulations of channel activities are the first events occurring in the plasma membrane and result in rapid perturbations of the plasma membrane potential (V(m)) involving variations of cytosolic Ca(2+) concentrations. Interacting downstream networks of kinases and phytohormones mediate the signal and result in concerted gene activation. Here we review and discuss early events occurring before herbivore attack-related gene expression that are responsible for cascades of events and signal transductions, eventually leading to indirect and direct plant responses. 相似文献
27.
Paulo FP Pimenta Alessandra S Orfano Ana C Bahia Ana PM Duarte Claudia M Ríos-Velásquez Fabrício F Melo Felipe AC Pessoa Giselle A Oliveira Keillen MM Campos Luis Martínez Villegas Nilton Barnabé Rodrigues Rafael Nacif-Pimenta Rejane C Sim?es Wuelton M Monteiro Rogerio Amino Yara M Traub-Cseko José BP Lima Maria GV Barbosa Marcus VG Lacerda Wanderli P Tadei Nágila FC Secundino 《Memórias do Instituto Oswaldo Cruz》2015,110(1):23-47
In the Americas, areas with a high risk of malaria transmission are mainly located in
the Amazon Forest, which extends across nine countries. One keystone step to
understanding the Plasmodium life cycle in Anopheles species from the Amazon Region
is to obtain experimentally infected mosquito vectors. Several attempts to colonise
Ano- pheles species have been conducted, but with only short-lived success or no
success at all. In this review, we review the literature on malaria transmission from
the perspective of its Amazon vectors. Currently, it is possible to develop
experimental Plasmodium vivax infection of the colonised and field-captured vectors
in laboratories located close to Amazonian endemic areas. We are also reviewing
studies related to the immune response to P. vivax infection of Anopheles aquasalis,
a coastal mosquito species. Finally, we discuss the importance of the modulation of
Plasmodium infection by the vector microbiota and also consider the anopheline
genomes. The establishment of experimental mosquito infections with Plasmodium
falciparum, Plasmodium yoelii and Plasmodium berghei parasites that could provide
interesting models for studying malaria in the Amazonian scenario is important.
Understanding the molecular mechanisms involved in the development of the parasites
in New World vectors is crucial in order to better determine the interaction process
and vectorial competence. 相似文献
28.
Shinichiro Maruyama Toshinobu Suzaki Andreas PM Weber John M Archibald Hisayoshi Nozaki 《BMC evolutionary biology》2011,11(1):105
Background
Euglenophytes are a group of photosynthetic flagellates possessing a plastid derived from a green algal endosymbiont, which was incorporated into an ancestral host cell via secondary endosymbiosis. However, the impact of endosymbiosis on the euglenophyte nuclear genome is not fully understood due to its complex nature as a 'hybrid' of a non-photosynthetic host cell and a secondary endosymbiont. 相似文献29.
Interactions between herbivorous insects and plants storing terpenoids are poorly understood. This study describes the ability of Chrysolina herbacea to use volatiles emitted by undamaged Mentha aquatica plants as attractants and the plant's response to herbivory, which involves the production of deterrent molecules. Emitted plant volatiles were analyzed by GC-MS. The insect's response to plant volatiles was tested by Y-tube olfactometer bioassays. Total RNA was extracted from control plants, mechanically damaged leaves, and leaves damaged by herbivores. The terpenoid quantitative gene expressions (qPCR) were then assayed. Upon herbivory, M. aquatica synthesizes and emits (+)-menthofuran, which acts as a deterrent to C. herbacea. Herbivory was found to up-regulate the expression of genes involved in terpenoid biosynthesis. The increased emission of (+)-menthofuran was correlated with the upregulation of (+)-menthofuran synthase. 相似文献
30.
Silencing of aphid genes by dsRNA feeding from plants 总被引:4,自引:0,他引:4