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91.
Benefits to plants in facultative ant protection mutualisms are highly variable. This allows examination of the sources of this variation and the mechanisms by which ants protect plants. We studied opportunistic interactions between ants and an extrafloral nectary-bearing vine, Dioscorea praehensilis, during 3 different years. Variation in plant protection among years was striking. Several factors affected the effectiveness of the biotic defence. Stems recently emerged from the underground tuber were self-supporting, contacting no other plants and encountering few foraging ants. Stems then became lianescent, and contact with supporting plants greatly increased ant recruitment. Both species and number of ant workers influenced the effect of ants on the major herbivore, the chrysomelid beetle Lilioceris latipennis. Protective actions included limitation of oviposition (reduction in the number of eggs laid on the plant) and predation, leading to increased larval mortality. The probability of successful predation was strongly dependent on larval size. If temporarily low ant-patrolling activity allows larvae to grow beyond a critical size, their mechanical (thick integument) or chemical (plant-derived compounds in a fecal shield) defences become more effective against ants. Secondary metabolites derived from the host plant thus appear to be important for the anti-predator mechanisms of this beetle, being necessary for its survival and reproduction on a host plant that actively recruits ants as a biotic defence against herbivores. 相似文献
92.
93.
J Edmond 《The Journal of biological chemistry》1974,249(1):72-80
94.
A tissue culture technique for rapid clonal propagation and storage under minimal growth conditions is presented in this paper. Shoot-tip cultures of Musa cultivars (both banana and plantain) are induced by culturing small excised shoot apices on modified MS semisolid medium supplemented with various concentrations and combinations of auxins and cytokinins. The effects of cytokinin concentration in the medium as well as the genotypic configuration of the cultivars on the rate of shoot-bud proliferation have been tested. The established shoot-tip cultures grown on modified MS semisolid medium supplemented with IAA (0.18 mg/l) and BA (2.30 mg/l) have been successfully stored at 15°C with 1000 lux light intensity up to 13–17 months depending on the cultivar. The cultivars tested in the present investigation seem to vary in their ability to withstand minimal growth temperature.Abbreviations BA
Benzyladenine
- IAA
Indoleacetic acid
- IBA
Indolebutyric acid
- MS
Murashige and Skoog 相似文献
95.
Edmond Dana Butler 《The Western journal of medicine》1950,73(6):481-488
Acute infections of the hand are serious and frequently arise from a trivial wound which has been neglected or improperly treated. Accurate diagnosis, prompt institution of treatment, and early restoration of function are essential for successful treatment. Results in the treatment of acute infections of the hand are greatly improved by the rigid practice of a method of operation which recognizes fundamental surgical principles. 相似文献
96.
97.
98.
Edmond A. D. Boyd 《CMAJ》1965,93(22):1178-1179
99.
Eisrhty-one unialgal isolates comprising 10 genera (Chlorophygeae, Cyanophyceae, Xanthophyceae) were cultured from samples of tree bark scrapings removed from 5 species of trees on the campus of Tennessee Wesleyan College in Athens, Tennessee, U.S.A. 相似文献
100.
Liakos Panagiotis; Bourmeyster Nicolas; Defaye Genevieve; Chambaz Edmond M.; Bottari Serge P. 《American journal of physiology. Cell physiology》1997,273(4):C1324
Angiotensin II(ANG II) has long been known for its pressor and growth-promotingeffects, which are both mediated by theAT1 receptor. By contrast, theAT2 receptor has recently beenreported to mediate inhibition of proliferation through as yetundefined mechanisms. We report here that in bovine adrenal fasciculata cells ANG II by itself does not affect growth but inhibits basic fibroblast growth factor (bFGF)-induced DNA synthesis and blocks thecells in G1 phase. Consistent withthis, ANG II inhibits cyclin D1 expression and cyclinD1-associated kinase activity. Theantimitogenic effect of ANG II is partly mimicked by theAT2-selective agonist CGP-42112.It is also blocked partly and in an additive fashion by theAT1- andAT2-selective antagonists losartanand PD-123319, indicating the contribution of both receptor subtypes tothis response. AT1-dependentantiproliferation is selectively blocked by the cyclooxygenaseinhibitor indomethacin and restored by prostaglandin E2, whereasAT2-receptor-mediated inhibitionof growth is suppressed by the tyrosine phosphatase inhibitorsorthovanadate and bpV(pic). Both pathways are, however,pertussis toxin sensitive. We hypothesize that, in fasciculatacells, the AT1 receptor inhibitsbFGF-induced proliferation by stimulating prostaglandin synthesis,whereas the AT2 receptor mediatesits effect through a pathway that requires protein tyrosine phosphataseactivation. 相似文献