Analysis of symbiotic signaling networks of arbuscular mycorrhiza and root nodule symbiosis.

丛枝菌根(AM)是一种植物与真菌的相互作用，对寄主植物的生长具有极大的优势。在这里，我们研究了AM突变体Cerberus和nsp1的AM表型，揭示了AM真菌感染的新的调控机制。对这些突变体的转录组分析表明，赤霉素(GA)信号转导影响AM真菌对寄主根部的侵染。详细分析GA对AM的影响表明，GA信号整合到共生信号中，并调控共生基因的表达。我们还分析了已分离到的与AM特异性顺式元件结合的转录调节因子RAMI1。对RAMI1的分析表明，RAMI1不仅在AM中发挥重要作用，而且在根瘤共生和非共生生理功能中也具有重要作用。

Arbuscular mycorrhiza (AM) is a plant-fungal interaction that confers great advantages for the host plant growth. Here we investigated AM phenotypes of AM mutants cerberus and nsp1 and revealed novel regulation mechanisms of AM fungal infection. Transcriptome analysis of these mutants indicated that gibberellin (GA) signaling affects AM fungal infection in the host root. Detailed analysis of GA effect on AM revealed that GA signaling integrated into symbiotic signaling and regulates symbiosis gene expression. We also analyzed RAMI1 that had been isolated as a transcriptional regulator that bind to AM specific cis element. Analysis of RAMI1 indicated that RAMI1 has important roles not only in AM but also in root nodule symbiosis and non-symbiotic physiological functions.