Effect of Potassium Ion Channels into the Spore Germination in Aspergillus flavus

Abstract:

Aflatoxin seriously polluted agricultural products and threatened the life and health of human and animal. Conidial germination is one of the most decisive factors in survival and invasion of A. flavus，and blocking germination could be one of the effective breakthrough points to keep contamination in the upstream controls. In this study，it was found that extracellular KCl could regulate the conidial germination in A. flavus. By using K+ specific fluorescent probe PBFI-AM，the results showed that a certain concentration of K+，which was suitable for spore germination，can stimulate A. flavus spores to produce higher potassium currents instantly，indicating that K⁺ response may be an early signal of spore germination. As a specific voltage potassium channels blocker，4-AP can obviously inhibit the spore germination. And KCNA is identified with K+-channel filter sequence by using bioinformatics prediction，and further analysis supports the potential of KCNA as voltage-gated potassium channel α subunit. In addition，the ion channel currents of KCNA expressed in Xenopus laevis oocyte were observed using two-electrode voltage clamp. Our studies indicated KCNA involving the regulation of conidial germination in A. flavus，which was one of voltage-gated potassium channels.