Nematode-induced trap formation regulated by the histone H3K4 methyltransferase AoSET1 in the nematode-trapping fungus Arthrobotrys oligospora

• Published in: Science China. Life sciences Vol. 66; no. 11; pp. 2663 - 2679
• Main Authors: Miao, Qiao, Wang, Zhengqi, Yin, Ziyu, Liu, Xiaoying, Li, Ran, Zhang, Ke-Qin, Li, Juan
• Format: Journal Article
• Language: English
• Published: Beijing Science China Press 01.11.2023; Springer Nature B.V
• Subjects: Arthrobotrys oligospora; Biomedical and Life Sciences; Conidia; Epigenetics; Fungi; Histone H3; Histone methyltransferase; Life Sciences; Methylation; Nematodes; Pathogenicity; Research Paper; Transcription factors; Trapping; trap formation; pathogenicity; histone modification; epigenetic regulatory; Arthrobotrys oligospora
• ISSN: 1674-7305; 1869-1889
• DOI: 10.1007/s11427-022-2300-2

The methylation of lysine 4 of histone H3 (H3K4), catalyzed by the histone methyltransferase KMT2/SET1, has been functionally identified in many pathogenic fungi but remains unexplored in nematode-trapping fungi (NTFs). Here, we report a regulatory mechanism of an H3K4-specific SET1 orthologue, AoSET1, in the typical nematode-trapping fungus Arthrobotrys oligospora . When the fungus is induced by the nematode, the expression of AoSET1 is up-regulated. Disruption of AoSet1 led to the abolishment of H3K4me. Consequently, the yield of traps and conidia of Δ AoSet1 was significantly lower than that of the WT strain, and the growth rate and pathogenicity were also compromised. Moreover, H3K4 trimethylation was enriched mainly in the promoter of two bZip transcription factor genes ( AobZip129 and AobZip350 ) and ultimately up-regulated the expression level of these two transcription factor genes. In the Δ AoSet1 and AoH3 K4A strains, the H3K4me modification level was significantly decreased at the promoter of transcription factor genes AobZip129 and AobZip350 . These results suggest that AoSET1-mediated H3KEme serves as an epigenetic marker of the promoter region of the targeted transcription factor genes. Furthermore, we found that AobZip129 negatively regulates the formation of adhesive networks and the pathogenicity of downstream AoPABP1 and AoCPR1. Our findings confirm that the epigenetic regulatory mechanism plays a pivotal role in regulating trap formation and pathogenesis in NTFs, and provide novel insights into the mechanisms of interaction between NTFs and nematodes.