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 l...背景：土曲霉（Aspergillus terreus）是危害人类、动物与植物的极具破坏性的丝状真菌病原之一。近期研究人员发现，土曲霉可引发马铃薯（Solanum tuberosum L.）的叶枯病。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，以期解析土曲霉侵染该重要农作物的过程。结果：显微观察显示，叶片组织的侵染以接种后4小时土曲霉瓶状分生孢子（phialidic conidia, PC）的快速萌发为标志性特征。接种后8小时，瓶状分生孢子产生的初生菌丝芽管分化为不规则突起，常表现出对气孔的趋性缺失，且无法通过表皮细胞完成侵入。叶片组织的定殖与附属分生孢子（accessory conidia, AC）的高水平产生密切相关。分析结果表明，附属分生孢子存在独特的分布模式：其具有组织特异性，且在侵染过程中于黑色素化的定殖菌丝上产生。