Zhao Xiaozhou, Fan Yani, Zhang Weiwei, Xiang Meichun, Kang Seogchan, Wang Shunxian, Liu Xingzhong
State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Science, Nankai University, Tianjin 300071, China.
State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Fungal Genet Biol. 2023 May;166:103782. doi: 10.1016/j.fgb.2023.103782. Epub 2023 Feb 26.
Calcium ion (Ca) is a universal second messenger involved in regulating diverse processes in animals, plants, and fungi. The low-affinity calcium uptake system (LACS) participates in acquiring Ca from extracellular environments under high extracellular Ca concentration. Unlike most fungi, which encode only one protein (FIG1) for LACS, nematode-trapping fungi (NTF) encode two related proteins. AoFIG_2, the NTF-specific LACS component encoded by adhesive network-trap forming Arthrobotrys oligospora, was shown to be required for conidiation and trap formation. We characterized the role of DhFIG_2, an AoFIG_2 ortholog encoded by knob-trap forming Dactylellina haptotyla, in growth and development to expand our understanding of the role of LACS in NTF. Because repeated attempts to disrupt DhFIG_2 failed, knocking down the expression of DhFIG_2 via RNA interference (RNAi) was used to study its function. RNAi of DhFIG_2 significantly decreased its expression, severely reduced conidiation and trap formation, and affected vegetative growth and stress responses, suggesting that this component of LACS is crucial for trap formation and conidiation in NTF. Our study demonstrated the utility of RNAi assisted by ATMT for studying gene function in D. haptotyla.
钙离子（Ca）是一种通用的第二信使，参与调节动物、植物和真菌中的多种过程。低亲和力钙吸收系统（LACS）在细胞外钙浓度较高的情况下参与从细胞外环境获取钙。与大多数仅编码一种LACS蛋白（FIG1）的真菌不同，捕食线虫真菌（NTF）编码两种相关蛋白。AoFIG_2是由形成粘性网络陷阱的少孢节丛孢菌编码的NTF特异性LACS组分，已证明其对分生孢子形成和陷阱形成是必需的。我们对由形成瘤状陷阱的哈氏隔指孢编码的AoFIG_2直系同源基因DhFIG_2在生长和发育中的作用进行了表征，以扩展我们对LACS在NTF中作用的理解。由于多次破坏DhFIG_2的尝试均失败，因此通过RNA干扰（RNAi）敲低DhFIG_2的表达来研究其功能。DhFIG_2的RNAi显著降低了其表达，严重减少了分生孢子形成和陷阱形成，并影响了营养生长和应激反应，这表明LACS的这一组分对NTF中的陷阱形成和分生孢子形成至关重要。我们的研究证明了ATMT辅助的RNAi在研究哈氏隔指孢基因功能方面的实用性。
