Data from: Invasion of Solanum tuberosum L. by Aspergillus terreus: a microscopic and proteomics insight on pathogenicity

Background: Aspergillus terreus is one of the most harmful filamentous fungal pathogen of humans, animals and plants. Recently, researchers have discovered that A. terreus can cause foliar blight disease in potato (Solanum tuberosum L.). We used light and scanning electron microscopy, and performed proteomics analysis in an attempt to dissect the invasion process of A. terreus in this important crop. Results: Microscopic study revealed that invasion of leaf tissue is marked by rapid germination of A. terreus phialidic conidia (PC) by 4 h after inoculation. By 8 h after inoculation, primary germ tubes from PC differentiated into irregular protuberance, often displayed stomata atropism, and failed to penetrate via the epidermal cells. Colonization of leaf tissues was associated with high rate of production of accessory conidia (AC). These analyses showed the occurrence of a unique opposing pattern of AC, tissue-specific and produced on melanized colonizing hyphae during the infection of leaf tissue. A significant proteome change hallmarked by differential expression of class I patatin, lipoxygenase, catalase-peroxidase complex, and cysteine proteinase inhibitor were observed during tuber colonization. These proteins are often involved in signal transduction pathways and crosstalk in pathogenic responses. Conclusion: A. terreus abundantly produced AC and multipolar germinating PC to invade potato leaf tissue. Additionally, A. terreus differentially induced enzymes in potato tuber during colonization which facilitates rapid disease development.

背景：土曲霉（Aspergillus terreus）是侵染人类、动物与植物的危害最为严重的丝状真菌病原菌之一。近期研究人员发现，土曲霉可引发马铃薯（Solanum tuberosum L.）产生叶枯病。本研究采用光学显微镜与扫描电子显微镜，并开展蛋白质组学分析，旨在解析土曲霉侵染该重要农作物的过程。
结果：显微研究表明，叶片组织的侵染以接种4小时后土曲霉瓶梗分生孢子（phialidic conidia，PC）的快速萌发为显著特征。接种8小时后，瓶梗分生孢子产生的初生芽管分化为不规则突起，常表现出气孔趋性缺失，且无法穿透表皮细胞。叶片组织的定殖与次生分生孢子（accessory conidia，AC）的大量产生紧密相关。分析结果显示，次生分生孢子存在一种独特的对立模式：具有组织特异性，且在侵染叶片组织时产生于黑化的定殖菌丝。在块茎定殖过程中，研究人员观察到显著的蛋白质组变化，其特征为Ⅰ类patatin蛋白（patatin）、脂氧合酶（lipoxygenase）、过氧化氢酶-过氧化物酶复合体（catalase-peroxidase complex）以及半胱氨酸蛋白酶抑制剂（cysteine proteinase inhibitor）的差异表达。上述蛋白通常参与信号转导通路以及病原响应过程中的信号串扰。
结论：土曲霉可大量产生次生分生孢子（AC）与多极萌发的瓶梗分生孢子，以此侵染马铃薯叶片组织。此外，土曲霉在块茎定殖过程中可诱导马铃薯块茎内的酶发生差异表达，进而加速病害的快速发展。