A Spore-Specific SscA is Essential for Conidial Viability And Dormancy in Aspergillus nidulans

Conidia (asexual spores) widely disseminate through the air and infect humans, animals, and plants. There are a myriad of regulators for conidiogenesis. Our previous studies presented that a spore-specific-C2H2 zinc finger A SscA is essential for proper conidia formation, conidia maturation, conidia dormancy and secondary metabolites in A. nidulans. Here, we further studied the genetic relationship between SscA and VosA (a master regulator of spore viability) on maintaining spore viability and dormancy in A. nidulans. The double deletion (ΔsscAΔvosA) conidia had significantly reduced long-term viability of spores and showed more severe reductions in trehalose contents compared to each single mutant conidia. Comparative transcriptomic analyses have revealed that both SscA and VosA affect stress resistance and developmental process in A. nidulans conidia. In fact, when assayed various stress sensitivity, the ΔsscAΔvosA conidia showed considerably lower viability compared to ΔsscA or ΔvosA conidia. The germination rate of double mutant conidia exhibited synergetic effects compared to each single mutant conidia. Taken together, we suggested that VosA and SscA play inter-dependent roles  in spore viability and dormancy by regulating stress- and development-related genes in A. nidulans.