Subtilase activity in the intrusive cells mediates haustorium maturation in parasitic plants
Subtilase activity in the intrusive cells mediates haustorium maturation in parasitic plants
复制标题
侵入细胞中的枯草杆菌酶活性介导寄生植物中吸器的成熟
DOI：
10.1101/2020.03.30.015149
复制
发表时间：
2020
期刊：
影响因子：
--
通讯作者：
K.
中科院分区：
文献类型：
--
作者：
Ogawa;S.;Wakatake;T.;Spallek;T.;Ishida;J;K.;Sano;R.;Kurata;T.;Demura;T.;Yoshida;S.;Ichihashi;Y.;Schaller;A.;Shirasu;K.
感染作物的寄生植物对全世界的农业都是毁灭性的。这些寄生虫发育出一种独特的可诱导器官，称为吸器，它连接寄生虫和宿主的血管系统，以建立水和营养物质的流动。在与宿主接触时，在与宿主界面处的吸器表皮细胞分化成称为侵入细胞的特定细胞，其朝向宿主脉管系统内生地生长。在此之后，一些侵入细胞重新分化形成木质部桥（XB），连接寄生虫和宿主的脉管系统。尽管侵入细胞在宿主感染中发挥着重要作用，但对侵入细胞介导寄生的分子机制仍知之甚少。在这项研究中，我们研究了差异基因表达的侵入细胞的兼性寄生Phtheirospermum japonicum在列当科的激光显微解剖吸器的RNA测序。然后，我们使用启动子分析来识别侵入细胞中特异性诱导的基因，并将启动子与编码荧光蛋白的基因融合以开发侵入细胞特异性标记。其中4个侵入细胞特异性基因编码枯草杆菌蛋白酶样丝氨酸蛋白酶（SBT），其在寄生植物中的生物学功能尚不清楚。SBT抑制剂在侵入细胞中的表达抑制侵入细胞和XB发育，并降低XB发育区域附近的生长素反应水平。因此，我们认为枯草杆菌酶活性在小麦吸器发育过程中起着重要作用。山茱萸
Parasitic plants that infect crops are devastating to agriculture throughout the world. These parasites develop a unique inducible organ called the haustorium that connects the vascular systems of the parasite and host to establish a flow of water and nutrients. Upon contact with the host, the haustorial epidermal cells at the interface with the host differentiate into specific cells called intrusive cells that grow endophytically toward the host vasculature. Following this, some of the intrusive cells re-differentiate to form a xylem bridge (XB) that connects the vasculatures of the parasite and host. Despite the prominent role of intrusive cells in host infection, the molecular mechanisms mediating parasitism in the intrusive cells remain poorly understood. In this study, we investigated differential gene expression in the intrusive cells of the facultative parasitePhtheirospermum japonicumin the family Orobanchaceae by RNA-sequencing of laser-microdissected haustoria. We then used promoter analyses to identify genes that are specifically induced in intrusive cells, and promoter fusions with genes encoding fluorescent proteins to develop intrusive cell-specific markers. Four of the identified intrusive cell-specific genes encode subtilisin-like serine proteases (SBTs), whose biological functions in parasitic plants are unknown. Expression of SBT inhibitors in intrusive cells inhibited both intrusive cell and XB development and reduced auxin response levels adjacent to the area of XB development. Therefore, we propose that subtilase activity plays an important role in haustorium development inP. japonicum.