The Beneficial Root-Colonizing Fungus Mortierella hyalina Promotes the Aerial Growth of Arabidopsis and Activates Calcium-Dependent Responses That Restrict Alternaria brassicae-Induced Disease Development in Roots
The Beneficial Root-Colonizing Fungus Mortierella hyalina Promotes the Aerial Growth of Arabidopsis and Activates Calcium-Dependent Responses That Restrict Alternaria brassicae-Induced Disease Development in Roots
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DOI：
10.1094/mpmi-05-18-0115-r
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发表时间：
2019-03-01
影响因子：
3.5
通讯作者：
Oelmueller, Ralf
中科院分区：
文献类型：
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作者：
Johnson, Joy Michal;Ludwig, Anatoli;Oelmueller, Ralf
内生真菌透明Mortierella hyalina定殖在拟南芥（Arabidopsis thaliana）的根部，刺激地上部分的生长和生物量产生，而不是根部。真菌的渗出部分在根中诱导快速和短暂的细胞质Ca2+升高。Ca2+反应不需要表征良好的（co）受体BAK1， CERK1和FLS2来进行病原体相关的分子模式，也不需要Ca2+通道GLR-2.4, GLR-2.5和GLR-3.3或液泡TWO PORE通道el1，它们可能参与细胞质Ca2+升高。我们分离了乙基甲烷磺酸诱导的拟南芥突变体，该突变体在Ca2+反应中受损。该突变体的根部在感染油菜互花菌后受到透明芽孢杆菌介导的免疫抑制，即茉莉酸盐的积累、活性氧的产生以及茉莉酸相关防御基因的激活。此外，它们比野生型根更容易被透明芽孢杆菌定殖。我们提出突变基因产物参与了由M. hyalina激活的Ca2+依赖性信号通路，以抑制拟南芥根系的免疫反应。
The endophytic fungus Mortierella hyalina colonizes the roots of Arabidopsis thaliana and stimulates growth and biomass production of the aerial parts but not of roots. An exudate fraction from the fungus induces rapid and transient cytoplasmic Ca2+ elevation in the roots. The Ca2+ response does not require the well-characterized (co)receptors BAK1, CERK1, and FLS2 for pathogen-associated molecular patterns, and the Ca2+ channels GLR-2.4, GLR-2.5, and GLR-3.3 or the vacuolar TWO PORE CHANNEL1, which might be involved in cytoplasmic Ca2+ elevation. We isolated an ethyl-methane-sulfonate-induced Arabidopsis mutant that is impaired in this Ca2+ response. The roots of the mutant are impaired in M. hyalina-mediated suppression of immune responses after Alternaria brassicae infection, i.e., jasmonate accumulation, generation of reactive oxygen species, as well as the activation of jasmonate-related defense genes. Furthermore, they are more colonized by M. hyalina than wild-type roots. We propose that the mutant gene product is involved in a Ca2+-dependent signaling pathway activated by M. hyalina to suppress immune responses in Arabidopsis roots.