A conserved fungal glycosyltransferase facilitates pathogenesis of plants by enabling hyphal growth on solid surfaces

Article Authors Metrics Comments Related Content Abstract Author summary Introduction Results and discussion Conclusions Methods Supporting information Acknowledgments References Reader Comments (0) Media Coverage (0) Figures Abstract Pathogenic fungi must extend filamentous hyphae across solid surfaces to cause diseases of plants. However, the full inventory of genes which support this is incomplete and many may be currently concealed due to their essentiality for the hyphal growth form. During a random T-DNA mutagenesis screen performed on the pleomorphic wheat (Triticum aestivum) pathogen Zymoseptoria tritici, we acquired a mutant unable to extend hyphae specifically when on solid surfaces. In contrast “yeast-like” growth, and all other growth forms, were unaffected. The inability to extend surface hyphae resulted in a complete loss of virulence on plants. The affected gene encoded a predicted type 2 glycosyltransferase (ZtGT2). Analysis of >800 genomes from taxonomically diverse fungi highlighted a generally widespread, but discontinuous, distribution of ZtGT2 orthologues, and a complete absence of any similar proteins in non-filamentous ascomycete yeasts. Deletion mutants of the ZtGT2 orthologue in the taxonomically un-related fungus Fusarium graminearum were also severely impaired in hyphal growth and non-pathogenic on wheat ears. ZtGT2 expression increased during filamentous growth and electron microscopy on deletion mutants (ΔZtGT2) suggested the protein functions to maintain the outermost surface of the fungal cell wall. Despite this, adhesion to leaf surfaces was unaffected in ΔZtGT2 mutants and global RNAseq-based gene expression profiling highlighted that surface-sensing and protein secretion was also largely unaffected. However, ΔZtGT2 mutants constitutively overexpressed several transmembrane and secreted proteins, including an important LysM-domain chitin-binding virulence effector, Zt3LysM. ZtGT2 likely functions in the synthesis of a currently unknown, potentially minor but widespread, extracellular or outer cell wall polysaccharide which plays a key role in facilitating many interactions between plants and fungi by enabling hyphal growth on solid matrices

Rethinking the Emergence of Relationship Marketing

In this article, the history of relationship marketing (RM) is challenged. Similar to discussions of the marketing concept, the debates surrounding RM are largely ahistorical. This is despite numerous scholars indicating that RM has a far longer history than is currently appreciated. In contrast to received wisdom that RM emerged in the late 1970s, it is demonstrated that RM themes have been present in the marketing literature for longer than is recognized by the contemporary scholars

Reflexing complexity: post-genomic knowledge and reductionist returns in public science.

Dominant social sciences approaches to complexity suggest that awareness of complexity in late-modern society comes from various recent scientific insights. By examining today’s plant and human genomics sciences, I question this from both ends: first suggesting that typical public culture was already aware of particular salient forms of complexity, such as limits to predictive knowledge (which are often denied by scientific cultures themselves); second, showing how up-to-date genomics science expresses both complexity and its opposites, predictive determinism and reductionism, as coexistent representations of nature and scientific knowledge. I suggest we can understand this self-authored epistemic confusion in modern science by avoiding ‘the usual suspects’ – fading simpler discourses left over from previous scientific times; media oversimplifications; or the need to ‘simplify’ to essentials, for ignorant publics – and looking instead at the silent imaginations of extra-scientific reference groups reflected and projectively performed in scientific discourses-practices themselves. Thus contradictions of complex scientific understandings are systematically created by science’s own embodiment of epistemic commitments influenced by commercial cultures, and by imagined publics who are important new constructed objects of institutional scientific concerns – over authority and trust. New dimensions of complexity thus come alive through paying attention to neglected tacit dimensions of science–society interrelations

Diffuse Phosphorus Models in the United States and Europe: Their Usages, Scales, and Uncertainties

Today there are many well-established computer models that are being used at different spatial and temporal scales to describe water, sediment, and P transport from diffuse sources. In this review, we describe how diffuse P models are commonly being used in the United States and Europe, the challenge presented by different temporal and spatial scales, and the uncertainty in model predictions. In the United States for water bodies that do not meet water quality standards, a total maximum daily load (TMDL) of the Pollutant of concern must be set that will restore water quality and a plan implemented to reduce the pollutant load to meet the TMDL. Models are used to estimate the current maximum daily and annual average load, to estimate the contribution from different nonpoint sources, and to develop scenarios for achieving the TMDL target. In Europe, the EC-Water Framework Directive is the driving force to improve water quality and models are playing a similar role to that in the United States, but the models being used are not the same. European models are more likely to take into account leaching of P and the identification of critical source areas. Scaling up to the watershed scale has led to overparameterized models that cannot be used to test hypotheses regarding nonpoint sources of P or transport processes using the monitoring data that is typically available. There is a need for more parsimonious models and monitoring data that takes advantage of the technological improvements that allow nearly continuous sampling for P and sediment. Tools for measuring model uncertainty must become an integral part of models and be readily available for model users