Hwu Fang-Yu, Lai Ming-Wei, Liou Ruey-Fen
Department of Plant Pathology and Microbiology, National Taiwan UniversityTaipei, Taiwan.
Front Microbiol. 2017 Apr 19;8:610. doi: 10.3389/fmicb.2017.00610. eCollection 2017.
is a notorious oomycete pathogen that causes severe disease in a wide variety of crop species. Infection of plants involves mainly its asexual life stage, including papillate sporangia and biflagellated zoospores, which are the primary dispersal and infection agents of this pathogen. Calcium signaling has been thought as the key regulator for sporangium formation and zoospore differentiation. However, not much is known about the molecular players involved in these processes. In , mating pheromone-induced death 1 () encodes a component of a putative calcium channel. Here, we identified and characterized the function of , an homolog from . The expression of was high in sporangia. Gene silencing of resulted in the formation of sporangia that lacked papilla and showed a tendency for direct germination. Notably, in response to cold shock to induce zoospore formation, these sporangia showed no sign of cytoplasmic cleavage and thereby failed to form zoospores. Nonetheless, the addition of CaCl or MgCl partially recovered the silenced sporangia phenotype, with the formation of papillate sporangia similar to those of the wild type and the release of zoospores upon cold shock. As well, virulence toward was reduced in the -silenced transformants. These results indicate a role of in the asexual development and virulence of .
是一种臭名昭著的卵菌病原体，可在多种作物物种中引发严重病害。植物感染主要涉及其无性繁殖阶段，包括乳头状孢子囊和双鞭毛游动孢子，它们是该病原体的主要传播和感染媒介。钙信号传导被认为是孢子囊形成和游动孢子分化的关键调节因子。然而，对于这些过程中涉及的分子参与者了解不多。在中，交配信息素诱导死亡1（）编码一种假定钙通道的成分。在这里，我们鉴定并表征了来自的同源物的功能。在孢子囊中高表达。基因沉默导致形成缺乏乳头的孢子囊，并表现出直接萌发的趋势。值得注意的是，在冷激诱导游动孢子形成时，这些孢子囊没有细胞质分裂的迹象，因此未能形成游动孢子。尽管如此，添加氯化钙或氯化镁部分恢复了沉默孢子囊的表型，形成了与野生型相似的乳头状孢子囊，并在冷激时释放游动孢子。同样，在沉默转化体中对的毒力降低。这些结果表明在的无性发育和毒力中起作用。
