Crosstalk of LaeA and CreA in controlling virulence and secondary metabolism in Penicillium expansum

J. Tannousa, X. Luob, D. Kumarc, S. Baradc,d, Y. Chene, A. Dubeyc, N.G. Matanac,d, S. Tian e, B. Li e, D. Pruskyc and N. Kellera,b,f

Author address: 

aDepartment of Medical Microbiology and Immunology, University of Wisconsin – Madison, Madison, WI 53706-1598, USA bDepartment of Plant Pathology, University of Wisconsin - Madison, Madison, WI 53706-1598, USA cDepartment of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani Center, Bet Dagan 50250, Israel dDepartment of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel eKey Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China fDepartment of Bacteriology, University of Wisconsin - Madison, Madison, WI 53706-1598, USA

Abstract: 

The plant pathogenic fungus Penicillium expansum is a major concern of the global food industry due to its wide occurrence and ability to produce various mycotoxins, of which the most significant is patulin. Although the patulin gene cluster has been recently identified and characterized, little is known on how it is regulated. Here we demonstrate that LaeA, a global regulator of mycotoxins in other fungi, is also required for the production of not only patulin but also other putative toxic secondary metabolites (SMs) produced by P. expansum as well as virulence on apple. We find that an increase of the sucrose molarity in the culture medium from 15 to 175 mM positively impacts creA expression, but conversely, decreases the expression of laeA and the accumulation of patulin by 5 and 175 fold, respectively. The increase in sucrose also negatively influences the expression of most of the SM synthase genes in P. expansum Pe-D1 strain. Independently, LaeA was deemed as a positive regulator of at least 6 SM gene clusters. Here we address the hypothesis that CreA regulation of laeA mediates many of the ΔlaeA phenotypes including regulation of SM clusters and virulence on apple.

2017

abstract No: 

71

Full conference title: 

The Fourteenth International Aspergillus Meeting, Asilomar Conference Center, Pacific Grove, CA, USA
    • Asperfest 14 (2017)