Chste11 was also found to ��be essential for sexual or asexual development, appressorial formation and pathogenicity. Although MAPK pathways are highly conserved and their components have been studied in a number of fungi, none of the MAPK genes has been functionally characterized in Bipolar is so rokiniana, the causal agent of spot blotch, common root rot and kernel blight in barley and wheat. In this study, we generated knockout mutants of the gene orthologues for four MAPK signaling components in B.sorokiniana, and demonstrated their roles in fungal development and virulence on leaves and roots of barley plants. Because of their increasing use in various products, nanoparticles have been very intensively studied on a toxicological point of view, with a special emphasis on pulmonary toxicity. The results described to date have been widely divergent, even for a given nanoparticle. For example, some results showed a strong pulmonary toxicity for titanium dioxide nanoparticles while others concluded to a low toxicity. This major discrepancy has been linked to the mode of administration in vivo, as well as to widely divergent doses used in the various studies. Moreover, these in vivo studies usually do not provide Sorafenib molecular mechanisms as to the responses of cells to the nanoparticles. As to in vitro studies, one of the the key cell types of interest is macrophages, which play a major role in the clearance of particles in the lung, including titanium dioxide nanoparticles, but also in several pulmonary diseases, as documented for SN-38 example in the case of asbestos. Other dysfunctions of the innate immune system can lead to deregulation of the immune responses and to severe adverse effects, e.g. a higher incidence of tumours. It is therefore not surprising that immune toxicology of nanoparticles is a developing field, and several studies have been devoted to the response of macrophages to nanoparticles. Within them, several have studied titanium dioxide, here again with quite divergent conclusions regarding the toxicity of titanium dioxide nanoparticles, at least in this cell type.