The Verticillium dahliae Spt-Ada-Gcn5 acetyltransferase complex subunit Ada1 is essential for conidia and microsclerotia production and contributes to virulence

Authors: GENG, QI - Nanjing Forestry University; LI, HUAN - Chinese Academy Of Agricultural Sciences; WANG, DAN - Chinese Academy Of Agricultural Sciences; SHENG, RUO-CHENG - Nanjing Forestry University; ZHU, HE - Liaoning Academy Of Agricultural Sciences; Klosterman, Steven; SUBBARAO, KRISHNA - University Of California; CHEN, JIEYIN - Chinese Academy Of Agricultural Sciences; CHEN, FENG-MAO - Nanjing Forestry University; ZHANG, DAN-DAN - Chinese Academy Of Agricultural Sciences

Submitted to: Frontiers in Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/31/2022
Publication Date: 2/23/2022
Citation: Geng, Q., Li, H., Wang, D., Sheng, R.C., Zhu, H., Klosterman, S.J., Subbarao, K.V., Chen, J.Y., Chen, F.M., Zhang, D.D. 2022. The Verticillium dahliae Spt-Ada-Gcn5 acetyltransferase complex subunit Ada1 is essential for conidia and microsclerotia production and contributes to virulence. Frontiers in Microbiology. 13. Article 852571. https://doi.org/10.3389/fmicb.2022.852571.
DOI: https://doi.org/10.3389/fmicb.2022.852571

Interpretive Summary: Verticillium dahliae is a plant pathogenic fungus that causes Verticillium wilt disease worldwide on numerous crop plants and ornamentals and also many trees. The fungus reproduces asexually by producing large numbers of short-lived conidia and survives long term in soils by producing survival structures known as microsclerotia, which are heavily melanized. The microsclerotia germinate and infect plant roots. In this study, we identified a gene in V. dahliae encoding a protein that renders the fungus defective in conidia, melanin, and microsclerotia production, and this gene also rendered the fungus defective in pathogenicity. Identification of the genes that control aspects of survival, asexual reproduction, and virulence in V. dahliae may lead to alternative control measures that inhibit its reproduction and formation of survival structures.

Technical Abstract: Verticillium dahliae is a destructive soil-borne pathogen of many economically important dicots. The genetics of pathogenesis in V. dahliae has been extensively studied. Spt-Ada-Gcn5 acetyltransferase complex (SAGA) is an ATP-independent multifunctional chromatin remodeling complex that contributes to diverse transcriptional regulatory functions. As members of the core module in the SAGA complex in Saccharomyces cerevisiae, Ada1, together with Spt7 and Spt20, play an important role in maintaining the integrity of the complex. In this study, we identified homologs of the SAGA complex in V. dahliae and found that deletion of the Ada1 subunit (VdAda1) causes severe defects in the formation of conidia and microsclerotia, and in melanin biosynthesis and virulence. The effect of VdAda1 on histone acetylation in V. dahliae was confirmed by western blot analysis. The deletion of VdAda1 resulted in genome-wide alteration of the V. dahliae transcriptome, including genes encoding transcription factors and secreted proteins, suggesting its prominent role in the regulation of transcription and virulence. Overall, we demonstrated that VdAda1, a member of the SAGA complex, modulates multiple physiological processes by regulating global gene expression that impinge on virulence and survival in V. dahliae.