Fujita Moeka, Kusajima Miyuki, Fukagawa Masatomo, Okumura Yasuko, Nakajima Masami, Akiyama Kohki, Asami Tadao, Yoneyama Koichi, Kato Hisaharu, Nakashita Hideo
Department of Bioscience and Biotechnology, Fukui Prefectural University, Eiheiji, Japan.
Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.
Sci Rep. 2022 Mar 18;12(1):4686. doi: 10.1038/s41598-022-08395-7.
Most plants interact with arbuscular mycorrhizal fungi, which enhance disease resistance in the host plant. Because the effects of resistance against bacterial pathogens are poorly understood, we investigated the effects of mycorrhizal colonization on virulent and avirulent pathogens using phytopathological and molecular biology techniques. Tomato plants colonized by Gigaspora margarita acquired resistance not only against the fungal pathogen, Botrytis cinerea, but also against a virulent bacterial pathogen, Pseudomonas syringae pv. tomato DC3000 (Pst). In G. margarita-colonized tomato, salicylic acid (SA)- and jasmonic acid (JA)-related defense genes were expressed more rapidly and strongly compared to those in the control plants when challenged by Pst, indicating that the plant immunity system was primed by mycorrhizal colonization. Gene expression analysis indicated that primed tomato plants responded to the avirulent pathogen, Pseudomonas syringae pv. oryzae, more rapidly and strongly compared to the control plant, where the effect on the JA-mediated signals was stronger than in the case with Pst. We found that the resistance induced by mycorrhizal colonization was effective against both fungal and bacterial pathogens including virulent and avirulent pathogens. Moreover, the activation of both SA- and JA-mediated signaling pathways can be enhanced in the primed plant by mycorrhizal colonization.
大多数植物与丛枝菌根真菌相互作用，这种真菌可增强宿主植物的抗病性。由于对抵抗细菌病原体的作用了解甚少，我们使用植物病理学和分子生物学技术研究了菌根定殖对毒性和无毒病原体的影响。被珠状巨孢囊霉定殖的番茄植株不仅获得了对真菌病原体灰葡萄孢的抗性，还获得了对毒性细菌病原体丁香假单胞菌番茄致病变种DC3000（Pst）的抗性。在被珠状巨孢囊霉定殖的番茄中，与水杨酸（SA）和茉莉酸（JA）相关的防御基因在受到Pst攻击时，与对照植株相比表达得更快且更强，这表明植物免疫系统因菌根定殖而被激活。基因表达分析表明，与对照植株相比，被激活的番茄植株对无毒病原体水稻白叶枯病菌的反应更快且更强，其中对JA介导信号的影响比对Pst的影响更强。我们发现，菌根定殖诱导的抗性对包括毒性和无毒病原体在内的真菌和细菌病原体均有效。此外，菌根定殖可增强被激活植株中SA和JA介导的信号通路的激活。
