PDF(Pubmed)
Abstract：
Orchids and arbuscular mycorrhiza (AM) plants evolved independently and have different structures and fungal partners, but they both facilitate nutrient uptake. Orchid mycorrhiza (OM) supports orchid seed germination, but unlike AM, its role in disease resistance of mature plants is largely unknown. Here, we examined whether OM induces systemic disease resistance against a necrotrophic pathogen in a similar fashion to AM. We investigated the priming effect of mycorrhizal fungi inoculation on resistance of a terrestrial orchid, Bletilla striata, to soft rot caused by Dickeya fangzhongdai. We found that root colonization by a compatible OM fungus primed B. striata seedlings and induced systemic resistance against the infection. Transcriptome analysis showed that priming was mediated by the downregulation of jasmonate and ethylene pathways and that these pathways are upregulated once infection occurs. Comparison with the reported transcriptome of AM fungus-colonized rice leaves revealed similar mechanisms in B. striata and in rice. These findings highlight a novel aspect of commonality between OM and AM plants in terms of induced systemic resistance.
摘要：
兰花和丛枝菌根（AM）植物独立进化，具有不同的结构和真菌伴侣，但它们都有助于营养吸收。兰花菌根（OM）支持兰花种子发芽，但与AM不同,其在成熟植物抗病性中的作用在很大程度上是未知的。这里,我们检查了OM是否以与AM相似的方式诱导针对坏死病原体的全身性疾病抗性。我们研究了菌根真菌接种对陆生兰花抗性的启动作用，白菜,由dickeyafangzhongdai引起的软腐病。我们发现，相容的OM真菌对B.striata幼苗的根部定植，并诱导了对感染的系统抗性。转录组分析表明，引发是由茉莉酸和乙烯途径的下调介导的，一旦发生感染，这些途径就会上调。与已报道的AM真菌定植水稻叶片的转录组进行比较，揭示了纹状体和水稻中相似的机制。这些发现突出了OM和AM植物在诱导的系统抗性方面的共性的新方面。
