Nordzieke Daniela Elisabeth
Genetics of Eukaryotic Microorganisms, Institute of Microbiology and Genetics, University of Göttingen, Grisebachstr. 8, 37077 Göttingen, Germany.
Microorganisms. 2022 Jun 1;10(6):1146. doi: 10.3390/microorganisms10061146.
Hyphal and germling fusion is a common phenomenon in ascomycetous fungi. Due to the formed hyphal network, this process enables a coordinated development as well as an interaction with plant hosts and efficient nutrient distribution. Recently, our laboratory work demonstrated a positive correlation between germling fusion and the formation of penetrating hyphopodia on maize leaves outgoing from oval conidia. To investigate the probable interconnectivity of these processes, we generated a deletion mutant in , in which homologs are essential for cellular fusion in other fungal species. However, hyphopodia development was not affected, indicating that both processes are not directly connected. Instead, we were able to link the cellular fusion defect in ∆ to a decreased formation of asexual fruiting bodies of on the leaves. The monitoring of a fluorescent-labelled autophagy marker, eGFP-CgAtg8, revealed a high autophagy activity in the hyphae surrounding the acervuli. These results support the hypothesis that the efficient nutrient transport of degraded cellular material by hyphal fusions enables proper acervuli maturation and, therefore, symptom development on the leaves.
菌丝和芽管融合是子囊菌中的常见现象。由于形成了菌丝网络，这一过程能够实现协调发育以及与植物宿主的相互作用，并实现高效的营养物质分配。最近，我们实验室的工作表明，从椭圆形分生孢子长出的芽管融合与玉米叶片上穿透性附着胞的形成之间存在正相关。为了研究这些过程可能的相互联系，我们构建了一个基因缺失突变体，在其他真菌物种中，该基因的同源物对于细胞融合至关重要。然而，附着胞的发育并未受到影响，这表明这两个过程没有直接联系。相反，我们能够将∆中的细胞融合缺陷与叶片上无性子实体形成减少联系起来。对荧光标记的自噬标记物eGFP-CgAtg8的监测显示，在分生孢子盘周围的菌丝中存在高自噬活性。这些结果支持了这样一种假设，即通过菌丝融合对降解的细胞物质进行高效营养运输能够使分生孢子盘正常成熟，从而导致叶片上出现症状。
