Molecular dialogue between arbuscular mycorrhizal fungi and the nonhost plant Arabidopsis thaliana switches from initial detection to antagonism
Molecular dialogue between arbuscular mycorrhizal fungi and the nonhost plant Arabidopsis thaliana switches from initial detection to antagonism
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DOI：
10.1111/nph.15798
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发表时间：
2019-07-01
期刊：
影响因子：
9.4
通讯作者：
van der Heijden, Marcel G. A.
中科院分区：
文献类型：
--
作者：
Fernandez, Ivan;Cosme, Marco;van der Heijden, Marcel G. A.
大约29%的维管植物物种不能建立丛枝菌根（AM）共生。尽管如此，AM真菌（Rhizophagus spp.）在非宿主拟南芥的根微生物组中富集，并且当宿主植物培育的AM网络可用时，拟南芥根成为定殖的。在这里，我们研究了非宿主AM真菌的相互作用，通过分析在Rhizophagus，拟南芥和宿主植物蒺藜苜蓿的转录变化，而在同一菌根网络中生长。在相互作用的早期阶段，Rhizophagus激活拟南芥独脚金内酯生物合成基因CCD 7和CCD 8，表明AM真菌的检测没有完全受损。然而，在殖民拟南芥根，真菌营养转运基因GintPT，GintAMT 2，GintMST 2和GintMST 4，AM共生必不可少的，没有被激活。RNA-seq转录组分析指出了在定殖的拟南芥根中昂贵的防御的激活。此外，Rhizophagus定植导致芽生物量减少50%，但也导致对灰葡萄孢的系统免疫增强。这表明AM真菌和拟南芥之间的早期信号并没有完全受损，不相容性出现在以后的相互作用阶段。此外，Rhizophagus介导的防御与拟南芥生长减少相一致，但也与系统性抗病性相一致，突出了AM真菌在宿主和非宿主相互作用中的多功能作用。
Approximately 29% of all vascular plant species are unable to establish an arbuscular mycorrhizal (AM) symbiosis. Despite this, AM fungi (Rhizophagus spp.) are enriched in the root microbiome of the nonhost Arabidopsis thaliana, and Arabidopsis roots become colonized when AM networks nurtured by host plants are available. Here, we investigated the nonhost-AM fungus interaction by analyzing transcriptional changes in Rhizophagus, Arabidopsis and the host plant Medicago truncatula while growing in the same mycorrhizal network. In early interaction stages, Rhizophagus activated the Arabidopsis strigolactone biosynthesis genes CCD7 and CCD8, suggesting that detection of AM fungi is not completely impaired. However, in colonized Arabidopsis roots, fungal nutrient transporter genes GintPT, GintAMT2, GintMST2 and GintMST4, essential for AM symbiosis, were not activated. RNA-seq transcriptome analysis pointed to activation of costly defenses in colonized Arabidopsis roots. Moreover, Rhizophagus colonization caused a 50% reduction in shoot biomass, but also led to enhanced systemic immunity against Botrytis cinerea. This suggests that early signaling between AM fungi and Arabidopsis is not completely impaired and that incompatibility appears at later interaction stages. Moreover, Rhizophagus-mediated defenses coincide with reduced Arabidopsis growth, but also with systemic disease resistance, highlighting the multifunctional role of AM fungi in host and nonhost interactions.