부산대학교 도서관

To purchase or authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1469-8137.2007.02233.x Byline: Vanessa Zabka (1), Michaela Stangl (1), Gerhard Bringmann (2), Gerd Vogg (1), Markus Riederer (1), Ulrich Hildebrandt (1) Keywords: Blumeria graminis; barley (Hordeum vulgare); hexacosanal; hexacosanol; hydrophobicity; mildew; wax Abstract: Summary The initial contact between Blumeria graminis f.sp. hordei and its host barley (Hordeum vulgare) takes place on epicuticular waxes at the surfaces of aerial plant organs. Here, the extent to which chemical composition, crystal structure and hydrophobicity of cuticular waxes affect fungal prepenetration processes was explored. The leaf surface properties of barley eceriferum (cer) wax mutants were characterized in detail. Barley leaves and artificial surfaces were used to investigate the early events of fungal infection. Even after epicuticular waxes had been stripped away, cer mutant leaf surfaces did not affect fungal prepenetration properties. Removal of total leaf cuticular waxes, however, resulted in a 20% reduction in conidial germination and differentiation. Two major components of barley leaf wax, hexacosanol and hexacosanal, differed considerably in their ability to effectively trigger conidial differentiation on glass surfaces. While hexacosanol, attaining a maximum hydrophobicity with contact angles of no more than 80, proved to be noninductive, hexacosanal significantly stimulated differentiation in c. 50% of B. graminis conidia, but only at contact angles > 80. These results, together with an observed inductive effect of highly hydrophobic, wax-free artificial surfaces, provide new insights into the interplay of physical and chemical surface cues involved in triggering prepenetration processes in B. graminis. Author Affiliation: (1)Universitat Wurzburg, Julius-von-Sachs-Institut fur Biowissenschaften, D-97082 Wurzburg, Germany; (2)Universitat Wurzburg, Institut fur Organische Chemie, D-97074 Wurzburg, Germany Article History: Received: 12 June 2007Accepted: 27 July 2007 Article note: Author for correspondence:, Ulrich Hildebrandt, Tel: +49 (0)931 888 6206, Fax: +49 (0)931 888 6235, Email: ulrich.hildebrandt@botanik.uni-wuerzburg.de