Department of Biosystems, KU Leuven, W. De Croylaan 42, 3001 Leuven, Belgium.
Department of Agronomy, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana, Slovenia.
J Plant Physiol. 2019 Sep;240:153008. doi: 10.1016/j.jplph.2019.153008. Epub 2019 Jul 10.
Hop (Humulus lupulus L.) is an important industrial plant providing ingredients for brewing and pharmaceutical industry worldwide. Its intensive production is challenged by numerous diseases. One of the most lethal and difficult to control is verticillium wilt, a vascular disease caused by the fungal pathogen Verticillium nonalfalfae. The disease can be successfully controlled by the host resistance. Despite various studies that already researched resistance mechanisms of hops, only limited number of resistance genes and markers that could be utilized for efficient resistance breeding has been identified. In this study we aimed to follow fungus colonization pattern and the differential expression of selected genes during pre-symptomatic period of susceptible (Celeia) and resistant (Wye Target) hop cultivars. Results of gene expressions and fungal colonisation of compatible and incompatible interactions with V. nonalfalfae suggest that the hop plant is challenged already at the very early fungal colonisation stages. In total, nine out of 17 gene targets investigated in our study resulted in differential expression between inoculated and control plants of susceptible and resistant cultivars. The difference was the most evident in stems at an early stage of colonisation (6 dpi), showing relatively stronger changes in targeted gene expression to infection in the resistant cultivar than in the susceptible one. Analysed gene targets are involved in the overall defence response processes of nucleic acid binding, signalling, protein ubiquitination, cell oxidative burst, hydroxylation, peroxidation, alternative splicing, and metabolite biosynthesis. The up-regulation of some genes (e.g. glycine-rich RNA-binding family protein, protein phosphatase, cysteine-rich receptor-like protein kinase, zinc finger CCCH domain-containing protein 40, cinnamic acid 4-hydroxylase, class III peroxidase, putative MAPK2, peroxiredoxin-2F) upon infection in incompatible interactions might reflect defence activation, restriction of disease spreading throughout the plant and successful response of resistant genotype.
啤酒花（Humulus lupulus L.）是一种重要的工业植物，为全球酿造和制药行业提供原料。其集约化生产受到多种疾病的挑战。其中最致命且难以控制的疾病之一是黄萎病，这是一种由真菌病原体萎蔫镰刀菌（Verticillium nonalfalfae）引起的维管束病害。该病害可以通过寄主抗性来有效控制。尽管已经有许多研究针对啤酒花的抗性机制进行了研究，但仅鉴定出了有限数量的抗性基因和标记，这些基因和标记可用于高效的抗性育种。在本研究中，我们旨在研究感病（Celeia）和抗病（Wye Target）啤酒花品种在真菌定殖前的基因表达差异。研究结果表明，在真菌定殖的早期阶段，啤酒花植株就已经受到了挑战。在总共研究的 17 个基因靶标中，有 9 个在接种和未接种的感病和抗病品种的植物中表现出差异表达。在早期定殖阶段（6dpi），茎中的差异最为明显，在抗病品种中，与感染相关的目标基因表达变化相对较强，而在感病品种中则较弱。分析的基因靶标参与了核酸结合、信号转导、蛋白质泛素化、细胞氧化爆发、羟化、过氧化、选择性剪接和代谢物生物合成等整体防御反应过程。一些基因（如甘氨酸丰富的 RNA 结合家族蛋白、蛋白磷酸酶、半胱氨酸富含受体样蛋白激酶、锌指 CCCH 结构域蛋白 40、肉桂酸 4-羟化酶、III 类过氧化物酶、假定 MAPK2、过氧化物酶体-2F）在不亲和互作中感染后的上调可能反映了防御的激活、限制病害在整个植株中的扩散以及抗病基因型的成功响应。
