Role of phytopathogenic fungi aldehyde dehydrogenases in mitigating cytotoxic effects of host aldehydes and aldehyde derivatives aldehyde-derivatives during pathogen-host interaction

Under persistent irritation from pathogenic microbes, plants deploy aldehydes and fatty acid derivatives as defense mechanisms through the prompt activation of oxylipin pathways and the cleavage of long-chain fatty acids to yield various carbon-length aldehydes. When responding to pathogen attacks, most aldehydes generated by plants directly kill the invading pathogens by accumulating at the site of infection. Aldehydes function as anti-phytopathogen molecules by inhibiting the growth of invading pathogens in host cells. They also serve as signaling molecules that mediate the induction of systemic resistance (SR). However, the role of Aldehyde dehydrogenases deployed by phytopathogenic fungi and oomycetes in countering aldehyde-induced plant defense remains understudied. In this review, we discuss the role of aldehyde dehydrogenases in the pathogenesis of plant pathogenic fungi and oomycetes. Finally, we provide insights into the potential of engaging fungal and oomycete aldehyde dehydrogenases as targets for developing antifungal compounds to support plant disease control programs.