Sensory cilia as the Achilles heel of nematodes when attacked by carnivorous mushrooms
Oyster mushrooms, one of the most common edible fungi, prey on nematodes under starvation conditions. They produce potent toxins which paralyze the nematodes within minutes. Dr. Yen-Ping Hsueh’s group at Institute of Molecular Biology, Academia Sinica, use the model nematode, Caenorhabditis elegans, to investigate how does mushroom paralyze and kill the nematodes. In their article titled “Sensory cilia as the Achilles heel of nematodes when attacked by carnivorous mushrooms” published in PNAS, they demonstrated that the contact of the fungal hyphae of oyster mushroom triggered massive calcium influx and rapid cell necrosis in the neuromuscular system of C. elegans via nematode’s sensory cilia. This study revealed a rapid nematode killing mechanism that has not been described previously and is distinct from that employed by common anthelmintic drugs, representing a potential new route for targeting parasitic nematodes infection in humans, animals and agriculture. It also establishes a new paradigm for studying cell death in C. elegans. The lead author for this work is Ching-Han Lee, a PhD student in the Academia Sinica TIGP-MCB program in the Hsueh Lab.
Article Link: https://www.pnas.org/content/117/11/6014
Natural diversity in the predatory behavior facilitates the establishment of a robust model strain for nematode-trapping fungi
The living component of soils and the interactions among them play central roles in various aspects of biogeochemistry. These include some of the most abundant organisms on Earth such as fungi and nematodes. The lab led by Dr. Yen-Ping Hsueh at the Institute of Molecular Biology of Academia Sinica studies the interactions between nematodes and nematode-trapping fungi (NTF). NTF are predatory fungi preying on nematodes when food sources are limited. A recent paper from the Hsueh lab, entitled “Natural diversity in the predatory behavior facilitates the establishment of a robust model strain for nematode-trapping fungi”, investigates the natural populations of nematodes and NTF in Taiwan. NTF were found to be ubiquitous in soils, present in more than 2/3 of soils samples collected in Taiwan, and in particular Arthrobotrys species were sympatric with various nematode species and behaved as generalist predators. The ability to sense prey varied greatly amongst different wild isolates of A. oligospora, the most common NTF found in nature, and strains with high sensitive to nematodes prey also developed traps faster. This polymorphic feature correlated with competency in prey killing and the phylogeny of A. oligospora natural strains. A chromosome level genome was assembled and annotated for a robust wild isolate that outperformed the current NTF model stain in growth fitness and predatory behavior. Finally, they also established that G protein signaling is required for predation in A. oligospora. In summary, this work revealed the natural history and the natural diversity of the predatory behavior of the nematode-trapping fungi. Genetic and genomic tools were further developed for a robust wild isolate of A. oligospora, enabling this strain to serve as a new model to study the molecular mechanisms of interactions between predatory fungi and nematodes. This study will help the development of using NTF as biocontrol tools to manage the parasitic nematode infections in agriculture. The lead authors for this work are Ching-Ting Yang and Dr. Dr. Guillermo Vidal-Diez de Ulzurrun
Article Link: https://www.pnas.org/content/117/12/6762
Ms. An-Chi Ma, Media Team, Secretariat, Central Administrative Office, Academia Sinica
Mr. Chung-Hui Chuang, Media Team, Secretariat, Central Administrative Office, Academia Sinica