Biology Department, Centre for Forest Biology, University of Victoria, PO Box 3020, STN CSC, Victoria, BC, Canada V8W 3N5.
Fungal Genet Biol. 2010 May;47(5):399-405. doi: 10.1016/j.fgb.2010.02.005. Epub 2010 Feb 20.
The fungal pathogen, Ophiostomo novo-ulmi, has been responsible for the rapid decline of American elm (Ulmus americana) across North America and remains a serious threat to surviving elm populations. The production of pectinolytic polygalacturonase enzymes has been implicated as a virulence factor for many fungal pathogens, including O. novo-ulmi. Previous work has shown that the targeted disruption of the endopolygalacturonase gene locus epg1 of O. novo-ulmi reduced, but did not eliminate pectinase activity. In the present study, we evaluated the use of RNA interference (RNAi) as a method of suppressing expression of the epg1 locus in O. novo-ulmi and compared its efficiency to the gene disruption method. While there was a reduction in epg1-specific mRNA transcripts and in the amount of polygalacturonase enzyme secreted for both methods of gene regulation, neither method completely suppressed the expression of pectinase activity. There was, however, a significantly greater reduction in both transcript levels and secreted enzyme observed for some of the RNAi transformants. As the first demonstration of RNAi in O. novo-ulmi, this method of gene regulation shows promise in future studies of gene expression and pathogenicity.
真菌病原体榆长喙壳菌（Ophiostomo novo-ulmi）是造成北美地区美洲榆（Ulmus americana）迅速减少的元凶，至今仍对幸存榆种群构成严重威胁。多聚半乳糖醛酸酶果胶酶的产生已被认为是许多真菌病原体（包括榆长喙壳菌）的一个毒力因子。先前的研究表明，靶向敲除榆长喙壳菌内切多聚半乳糖醛酸酶基因座 epg1 虽降低了果胶酶活性，但并未完全消除。在本研究中，我们评估了 RNA 干扰（RNAi）作为一种抑制榆长喙壳菌 epg1 基因座表达的方法，并将其与基因敲除方法进行了比较。尽管两种基因调控方法都降低了 epg1 特异性 mRNA 转录本和分泌的多聚半乳糖醛酸酶的量，但都没有完全抑制果胶酶活性。然而，对于一些 RNAi 转化体，观察到转录本水平和分泌酶的降低更为显著。作为 RNAi 在榆长喙壳菌中的首次应用，这种基因调控方法在未来的基因表达和致病性研究中显示出了一定的前景。
