Cross-tolerance to abiotic stresses in halophytes: Application for phytoremediation of organic pollutants

International audienceHalopytes are plants able to tolerate high salt concentrations but no clear definition was retained for them. In literature, there are more studies that showed salt-enhanced tolerance to other abiotic stresses compared to investigations that found enhanced salt tolerance by other abiotic stresses in halophytes. The phenomenon by which a plant resistance to a stress induces resistance to another is referred to as cross-tolerance. In this work, we reviewed cross-tolerance in halophytes at the physiological, biochemical, and molecular levels. A special attention was accorded to the cross-tolerance between salinity and organic pollutants that could allow halophytes a higher potential of xenobiotic phytoremediation in comparison with glycophytes

Dependence of tribofilm characteristics on the running-in behavior of aluminum–silicon alloys

In this study, we evaluate the evolution of the interfacial processes in metallic sliding contacts (i.e., aluminum alloys) in terms of their elemental composition, structural changes, and nanomechanical properties in order to understand the optimal running-in behavior leading to steady-state low friction and high wear resistance. Two different sliding conditions are used, resulting in low and high long-term friction and corresponding well with the low and high wear rates. Ex situ elemental analysis of these sliding experiments was performed by means of X-ray photoelectron spectroscopy. The mechanical properties were evaluated using nanoindentation and microcompression testing. While the elemental analysis revealed an increased oxide content for the near-surface region of the worn surfaces compared to the unworn material, the oxide content was higher for the experiments that resulted in an unfavorable tribological response (i.e., high friction and high wear). Similarly, the sub-surface grain-refined layer under these conditions was thicker compared to the experiment with a short running-in stage and low steady-state friction and wear. These observations correlated well with the nanoindentation and microcompression results, which show higher hardness and yield stress for the high friction and wear experiment. Correspondingly, low steady-state friction and wear were obtained with the formation of a thin and mechanically stable tribolayer