Boddu Jayanand, Cho Seungho, Kruger Warren M, Muehlbauer Gary J
Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul, MN 55108, USA.
Mol Plant Microbe Interact. 2006 Apr;19(4):407-17. doi: 10.1094/MPMI-19-0407.
Fusarium head blight (FHB) of barley (Hordeum vulgare L.) is caused by Fusarium graminearum. FHB causes yield losses and reduction in grain quality primarily due to the accumulation of trichothecene mycotoxins such as deoxynivalenol (DON). To develop an understanding of the barley-F. graminearum interaction, we examined the relationship among the infection process, DON concentration, and host transcript accumulation for 22,439 genes in spikes from the susceptible cv. Morex from 0 to 144 h after F. graminearum and water control inoculation. We detected 467 differentially accumulating barley gene transcripts in the F. graminearum-treated plants compared with the water control-treated plants. Functional annotation of the transcripts revealed a variety of infection-induced host genes encoding defense response proteins, oxidative burst-associated enzymes, and phenylpropanoid pathway enzymes. Of particular interest was the induction of transcripts encoding potential trichothecene catabolic enzymes and transporters, and the induction of the tryptophan biosynthetic and catabolic pathway enzymes. Our results define three stages of E graminearum infection. An early stage, between 0 and 48 h after inoculation (hai), exhibited limited fungal development, low DON accumulation, and little change in the transcript accumulation status. An intermediate stage, between 48 and 96 hai, showed increased fungal development and active infection, higher DON accumulation, and increased transcript accumulation. A majority of the host gene transcripts were detected by 72 hai, suggesting that this is an important timepoint for the barley-F. graminearum interaction. A late stage also identified between 96 and 144 hai, exhibiting development of hyphal mats, high DON accumulation, and a reduction in the number of transcripts observed. Our study provides a baseline and hypothesis-generating dataset in barley during F. graminearum infection and in other grasses during pathogen infection.
大麦（Hordeum vulgare L.）的赤霉病（FHB）由禾谷镰刀菌（Fusarium graminearum）引起。赤霉病主要由于诸如脱氧雪腐镰刀菌烯醇（DON）等单端孢霉烯族真菌毒素的积累而导致产量损失和谷物品质下降。为了深入了解大麦与禾谷镰刀菌的相互作用，我们研究了易感品种Morex穗部在禾谷镰刀菌接种和水对照接种后0至144小时内22,439个基因的感染过程、DON浓度和宿主转录本积累之间的关系。与水对照处理的植株相比，我们在禾谷镰刀菌处理的植株中检测到467个差异积累的大麦基因转录本。对这些转录本的功能注释揭示了多种感染诱导的宿主基因，这些基因编码防御反应蛋白、氧化爆发相关酶和苯丙烷类途径酶。特别令人感兴趣的是编码潜在单端孢霉烯族真菌毒素分解代谢酶和转运蛋白的转录本的诱导，以及色氨酸生物合成和分解代谢途径酶的诱导。我们的结果确定了禾谷镰刀菌感染的三个阶段。接种后（hai）0至48小时的早期阶段，真菌发育有限，DON积累较低，转录本积累状态变化不大。48至96 hai的中间阶段，真菌发育增加且感染活跃，DON积累较高，转录本积累增加。到72 hai时检测到大多数宿主基因转录本，这表明这是大麦与禾谷镰刀菌相互作用的一个重要时间点。还确定了96至144 hai的后期阶段，表现为菌丝体垫的发育、高DON积累以及观察到的转录本数量减少。我们的研究为大麦在禾谷镰刀菌感染期间以及其他禾本科植物在病原体感染期间提供了一个基线和产生假设的数据集。
