Natural product 2-Phenylethanol inhibits ATP synthesis of P. infestans by blocking the oxidative phosphorylation pathway to prevent potato late blight

Abstract

Potato tuber rots caused by the late blight pathogens oomycete Phytophthora infestans results in severe postharvest losses in transit and storage. Natural volatile organic compounds (VOCs) produced by antagonistic microorganisms have good biocontrol effects. However, VOCs for controlling potato late blight largely remains scarcity, the antimicrobial mechanisms were not entirely clear. In this study, an antagonistic yeast Candida quercitrusa strain Cq-1 was reported that had strong anti-oomycete activity on P. infestans. Its natural VOCs are mainly attributable to the inhibitory ability at the inhibition rate of 85.94%. Mycelial growth of P. infestans and lesions on postharvest potato tubers were inhibited after exposure to its VOCs by storage simulation assay. Furthermore, 2-Phenylethanol (C8H10O) (2-PE) was identified as one of the primary components of VOCs in C. quercitrusa through GC-MS. Hyphal growth of P. infestans following 2-PE treatment was malformed and shriveling. Mechanism investigations revealed that 2-PE blocked the oxidative phosphorylation pathway from RNA-seq analysis, the down-regulation of relevant genes was validated by qPCR, eventually causing a 68.08% reduction in ATP contents, thereby leading to ATP depletion and ultimate mortality of P. infestans. Hence, 2-PE suggesting potential application to protect postharvest potato tubers from late blight.