USDA-ARS, Soil-Plant-Nutrient Research, Fort Collins, CO, USA.
J Chem Ecol. 2013 Jun;39(6):733-43. doi: 10.1007/s10886-013-0295-y. Epub 2013 May 21.
Elicitin-mediated acquisition of plant sterols is required for growth and sporulation of Phytophthora spp. This study examined the interactions between elicitins, sterols, and tannins. Ground leaf tissue, sterols, and tannin-enriched extracts were obtained from three different plant species (California bay laurel, California black oak, and Oregon white oak) in order to evaluate the effect of differing sterol/tannin contents on Phytophthora ramorum growth. For all three species, high levels of foliage inhibited P. ramorum growth and sporulation, with a steeper concentration dependence for the two oak samples. Phytophthora ramorum growth and sporulation were inhibited by either phytosterols or tannin-enriched extracts. High levels of sterols diminished elicitin gene expression in P. ramorum; whereas the tannin-enriched extract decreased the amount of 'functional' or ELISA-detectable elicitin, but not gene expression. Across all treatment combinations, P. ramorum growth and sporulation correlated strongly with the amount of ELISA-detectable elicitin (R (2) = 0.791 and 0.961, respectively).
激发素介导的植物甾醇获取对于疫霉属植物的生长和孢子形成是必需的。本研究探讨了激发素、甾醇和单宁之间的相互作用。从三种不同的植物物种（加利福尼亚月桂、加利福尼亚黑栎和俄勒冈白栎）获得了叶组织、甾醇和富含单宁的提取物，以评估不同甾醇/单宁含量对松材线虫生长的影响。对于所有三种物种，高水平的叶片抑制了松材线虫的生长和孢子形成，而在两个栎属样本中，浓度依赖性更强。松材线虫的生长和孢子形成受到植物甾醇或富含单宁的提取物的抑制。高水平的甾醇会减弱松材线虫中激发素基因的表达；而富含单宁的提取物则降低了“功能性”或 ELISA 可检测的激发素的含量，但不影响基因表达。在所有处理组合中，松材线虫的生长和孢子形成与 ELISA 可检测的激发素含量密切相关（R (2)分别为 0.791 和 0.961）。
