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Drought‐stress and plant resistance affect herbivore performance and proteome: the case of the green peach aphid Myzus persicae (Hemiptera: Aphididae) 下载免费PDF全文
Jaime A. Verdugo Marie‐Helene Sauge Jean‐Philippe Lacroze Frederic Francis Claudio C. Ramirez 《Physiological Entomology》2015,40(4):265-276
Little is known about the simultaneous effects of drought stress and plant resistance on herbivorous insects. By subjecting the green peach aphid Myzus persicae Sulzer to well‐watered and drought‐stressed plants of both susceptible and resistant peach (Prunus persica), the effects of both stressors on aphid performance and proteomics are tested. Overall, the influence of the water treatment on aphid performance is less pronounced than the effect of host plant genetic resistance. On the susceptible cultivar, aphid survival, host acceptance and ability to colonize the plant do not depend on water treatment. On the resistant cultivar, aphid survival and ability to colonize are higher on drought‐stressed than on well‐watered plants. A study examining the pattern of protein expression aiming to explain the variation in aphid performance finds higher protein expression in aphids on the drought‐stressed susceptible cultivars compared with the well‐watered ones. In the susceptible cultivar, the regulated proteins are related to energy metabolism and exoskeleton functionality, whereas, in the resistant cultivar, the proteins are involved with the cytoskeleton. Comparison of the protein expression ratios for resistant versus susceptible plants reveals that four proteins are down‐regulated in well‐watered plants and 15 proteins are down‐regulated in drought‐stressed plants. Drought stress applied to the susceptible cultivar induces the regulation of proteins in M. persicae that enable physiological adaptation to maintain an almost unaltered aphid performance. By contrast, for aphids on the resistant cultivar subjected to drought stress, the down‐regulation of proteins responds to an induced host susceptibility effect. 相似文献
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Christian Viskov Stefano Elli Elena Urso Davide Gaudesi Pierre Mourier Frederic Herman Christian Boudier Benito Casu Giangiacomo Torri Marco Guerrini 《The Journal of biological chemistry》2013,288(36):25895-25907
The antithrombin (AT) binding properties of heparin and low molecular weight heparins are strongly associated to the presence of the pentasaccharide sequence AGA*IA (ANAc,6S-GlcUA-ANS,3,6S-I2S-ANS,6S). By using the highly chemoselective depolymerization to prepare new ultra low molecular weight heparin and coupling it with the original separation techniques, it was possible to isolate a polysaccharide with a biosynthetically unexpected structure and excellent antithrombotic properties. It consisted of a dodecasaccharide containing an unsaturated uronate unit at the nonreducing end and two contiguous AT-binding sequences separated by a nonsulfated iduronate residue. This novel oligosaccharide was characterized by NMR spectroscopy, and its binding with AT was determined by fluorescence titration, NMR, and LC-MS. The dodecasaccharide displayed a significantly increased anti-FXa activity compared with those of the pentasaccharide, fondaparinux, and low molecular weight heparin enoxaparin. 相似文献
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One of the potential explanations for negative compatibility effects (NCE) in subliminal motor priming tasks has been perceptual prime-target interactions. Here, we investigate whether the characteristic tri-phasic LRP pattern associated with the NCE is caused by these prime-target interactions. We found that both the prime-related phase and the critical reversal phase remain present even on trials where the target is omitted, confirming they are elicited by the prime and mask, not by prime-target interactions. We also report that shape and size of the reversal phase are associated with response speed, consistent with a causal role for the reversal for the subsequent response latency. Additionally, we analysed sequential modulation of the NCE by previous conflicting events, even though such conflict is subliminal. In accordance with previous literature, this modulation is small but significant. 相似文献
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Advantage Provided by Iron for Escherichia coli Growth and Cultivability in Drinking Water 下载免费PDF全文
Brice M. R. Appenzeller Carolina Ya?ez Frederic Jorand Jean-Claude Block 《Applied microbiology》2005,71(9):5621-5623
The presence of iron, used both as a nutrient and as an electron acceptor, was demonstrated to give an advantage to Escherichia coli bacteria in drinking water. Slight additions of ferrous sulfate to water with initial low iron concentrations led to a significant increase in the number of E. coli bacteria. The presence of ferric oxide in water under anaerobic conditions increased bacterial cultivability. 相似文献
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Ultramafic soils at Bandalup Hill (Western Australia) are characterised by high concentrations of Ni and low levels of P.
Amongst the plant species that can sustain such hostile conditions, Hakea verrucosa F. Muell from a non-mycorrhizal family (Proteaceae) would be expected to rely on cluster roots to access P. However, the
acidification of ultramafic soils by cluster roots might increase the dissolution of soil Ni, and therefore its availability
to plants. Symbiosis with mycorrhizal fungi, on the other hand, might help to reduce the uptake of Ni by H. verrucosa. Therefore, the aim of this study was to investigate the mycorrhizal status of H. verrucosa, and assess any contribution from mycorrhizal fungi to its growth and nutrient status. Seedlings of H. verrucosa were first grown in undisturbed ultramafic soil cores from Bandalup Hill for 8 weeks to assess the presence of mycorrhizal
fungi in their roots. In a second experiment, H. verrucosa seedlings were grown in the same ultramafic soil that was either steamed or left untreated. Seedlings were inoculated with
an arbuscular mycorrhizal (AM) fungal consortium from Bandalup Hill. Fungal hyphae, vesicles, as well as intracellular arbuscules
and hyphal coils were observed in the cluster roots of H. verrucosa in both experiments. In the first experiment, 57% of the root length was colonized by AM fungi. Seedlings had high (between
1.4 and 1.9) shoot to root ratios and their roots had very few root hairs, despite growing in P-deficient soil. Steaming of
the ultramafic soil increased the growth of seedlings and their nutrient uptake. Inoculation with AM fungi reduced the seedling
growth in steamed ultramafic soil; however, it increased their shoot P and K concentration and also the shoot K content. The
shoot Ni concentration of seedlings was not affected by the presence of AM fungi. 相似文献