College of Plant Science, Jilin University, Changchun, Jilin, China; Section of Plant Pathology and Plant-Microbe Biology, School of Integrative Plant Science, Cornell University, Ithaca, NY, United States.
Section of Plant Pathology and Plant-Microbe Biology, School of Integrative Plant Science, Cornell University, Ithaca, NY, United States.
Fungal Genet Biol. 2020 Feb;135:103291. doi: 10.1016/j.fgb.2019.103291. Epub 2019 Nov 4.
Septins are highly conserved GTP-binding proteins that function in cell cytokinesis, polarity and morphogenesis. To evaluate the roles of these proteins in inoculum health and disease, mutants deleted for each of five septin proteins (Cdc3, Cdc10, Cdc11, Cdc12, and Cdc100) were characterized in the ascomycete Cochliobolus heterostrophus for ability to develop asexual and sexual spores and for virulence to the host maize. Strains deleted for CDC3, CDC10, CDC11, and CDC12 genes showed significant changes in hyphal growth, and in development of conidia and ascospores compared to the wild-type strain. Conidia had dramatically reduced numbers of septa and rates of germination, while ascospore development was blocked in the meiotic process. Although asci were produced, wild-type ascospores were not. When equal numbers of conidia from wild type and mutants were used to inoculate maize, cdc10 mutants showed reduced virulence compared to the wild-type strain and other mutants. This reduced virulence was demonstrated to be correlated with lower germination rate of cdc10 mutant conidia. When adjusted for germination rate, virulence was equivalent to the wild-type strain. Double mutants (cdc3cdc10, cdc3cdc11) showed augmented reduced growth phenotypes. cdc100 mutants were wild type in all assays. Taken together, these findings indicate that all four conserved septin proteins play a major role in reproductive propagule formation and that mutants with deletions of CDC10 are reduced in virulence to the host maize.
septins 是高度保守的 GTP 结合蛋白，它们在细胞胞质分裂、极性和形态发生中发挥作用。为了评估这些蛋白质在接种物健康和疾病中的作用，我们对五个 septin 蛋白（Cdc3、Cdc10、Cdc11、Cdc12 和 Cdc100）缺失突变体的子囊菌 Cochliobolus heterostrophus 进行了特征描述，以评估它们发育无性和有性孢子的能力以及对宿主玉米的毒力。与野生型菌株相比，缺失 CDC3、CDC10、CDC11 和 CDC12 基因的菌株在菌丝生长和分生孢子和子囊孢子发育方面表现出明显的变化。与野生型菌株相比，分生孢子的隔膜数量和萌发率显著降低，而减数分裂过程中的子囊孢子发育受阻。尽管产生了子囊，但没有产生野生型子囊孢子。当使用等量的野生型和突变体分生孢子接种玉米时，与野生型菌株和其他突变体相比，cdc10 突变体显示出较低的毒力。这种降低的毒力与 cdc10 突变体分生孢子较低的萌发率相关。当根据萌发率进行调整时，毒力与野生型菌株相当。双突变体（cdc3cdc10、cdc3cdc11）表现出增强的生长表型降低。cdc100 突变体在所有测定中均为野生型。综上所述，这些发现表明所有四个保守的 septin 蛋白在生殖繁殖体形成中起主要作用，并且缺失 CDC10 的突变体在对宿主玉米的毒力方面降低。
