Regulation of Conidiation and Aflatoxin B1 Biosynthesis by a Blue Light Sensor LreA in Aspergillus flavus

Abstract

Conidia are important for the dispersal of Aspergillus flavus, which usually generates aflatoxin B1 (AFB1) and poses a threat to the safety of agricultural food. The development of conidia is usually susceptible to changes in environmental conditions, such as nutritional status and light. However, how the light signal is involved in the conidiation in A. flavus is still unknown. In this study, LreA was identified to respond to blue light and mediate the promotion of conidiation in A. flavus, which is related to the central development pathway. At the same time, blue light inhibited the biosynthesis of AFB1, which was mediated by LreA and attributed to the transcriptional regulation of aflR and aflS expression. Our findings disclosed the function and mechanism of the blue light sensor LreA in regulating conidiation and AFB1 biosynthesis, which is beneficial for the prevention and control of A. flavus and mycotoxins.