Submitted to: Letters in Applied Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 22, 2010
Publication Date: May 22, 2010
Citation: Kim, J.H., Campbell, B.C., Mahoney, N.E., Chan, K.L., Molyneux, R.J., Xiao, C. 2010. Use of chemosensitization to overcome fludioxonil-resistance in Penicillium expansum. Letters Appl. Microbiol. DOI: 10.1111/j.1472-765X Interpretive Summary: Production of apples can be hampered by fungal infections. Fungal infections can cause unsightly blemishes, or apple rot. Moreover, they can produce certain toxins that can make people sick. Infection of apples by fungi can occur in the orchard, before harvest, or when in storage, after harvest. To combat fungal infections, apples are treated with fungicides. However, the development of resistance to fungicides is an ever-increasing problem for the industry. ARS scientists have found a way to improve the effectiveness of fungicides and to, also, make resistant fungi susceptible to fungicides. This greater sensitivity is achieved through "chemosensitization", the use of safe natural products to undermine the ability of the fungi to respond to fungicidal treatments. This finding can help the apple industry by improving its ability to tackle the problem of apple rot.
Technical Abstract: Resistance in two mutant strains of Penicillium expansum to the fungicide fludioxonil was overcome by co-application of natural phenolic chemosensitizing agents that targeted various elements of the oxidative stress-response pathway. Fludioxonil resistance in these strains resulted from cell-linked interruption of normal redox homeostasis. Natural phenolic chemosensitizing agents were also found that augmented effectiveness of the fungicide, strobilurin. The efficacy of using natural, safe products as chemosensitizing agents to enhance efficacy of commercial fungicides for controlling a broad spectrum of fungal pathogens is discussed.