Natural Resources Canada, Canadian Forest Service, Pacific Forestry Centre, 506 West Burnside Road, Victoria, BC, V8Z 1M5, Canada.
Phytopathology. 2013 Jun;103(6):583-93. doi: 10.1094/PHYTO-04-12-0086-R.
Douglas-fir (DF) (Pseudotsuga menziesii) is one of the largest and most economically important coniferous species in western North America. Its productivity is greatly affected by the root rot fungus Phellinus sulphurascens Pilát. Evidence of resistance by DF to fungal root pathogens such as P. sulphurascens has been reported but mechanisms of resistance in this compatible pathosystem are not yet known. To better understand the DF-P. sulphurascens interaction, especially at the molecular level, we selected 12 diverse plant genes already identified as defense-related from a cDNA library constructed using root tissues from P. sulphurascens-infected DF seedlings. Using quantitative reverse-transcriptase polymerase chain reaction on infected DF root samples collected at five different time points after inoculation, we found that P. sulphurascens infection significantly elevated expression of the 12 selected genes. In most cases the highest expression level was recorded within 2 to 3 days after inoculation. The constructed cDNA library, which is enriched with defense-related host genes and a number of fungal genes, will continue to serve as a useful resource for future larger-scale gene discovery and functional research on the P. sulphurascens and DF pathosystem.
花旗松（DF）（Pseudotsuga menziesii）是北美西部最大和最重要的经济针叶树种之一。其生产力受硫磺软木层孔菌（Phellinus sulphurascens Pilát）等根腐真菌的极大影响。已有报道称 DF 对真菌根病原体如 P. sulphurascens 具有抗性，但在这种相容的病理系统中，抗性机制尚不清楚。为了更好地了解 DF-硫磺软木层孔菌的相互作用，特别是在分子水平上，我们从硫磺软木层孔菌感染的 DF 幼苗根组织构建的 cDNA 文库中选择了 12 种已鉴定为与防御相关的不同植物基因。在接种后五个不同时间点采集的感染 DF 根样本中，使用定量逆转录聚合酶链反应，我们发现硫磺软木层孔菌感染显著提高了 12 种选定基因的表达。在大多数情况下，接种后 2 至 3 天内记录到最高表达水平。该构建的 cDNA 文库富含与防御相关的宿主基因和一些真菌基因，将继续作为未来硫磺软木层孔菌和 DF 病理系统的更大规模基因发现和功能研究的有用资源。
