Mining RNA-Seq Data to Depict How Penicillium digitatum Shapes Its Transcriptome in Response to Nanoemulsion

Abstract

Penicillium digitatum is the most severe pathogen that infects citrus fruits during storage. It can cause fruit rot and bring significant economic losses. The continuous use of fungicides has resulted in the emergence of drug-resistant strains. Consequently, there is a need to develop naturally and efficiently antifungal fungicides. Natural antimicrobial agents such as clove oil, cinnamon oil, and thyme oil can be extracted from different plant parts. They exhibited broad-spectrum antimicrobial properties and have great potential in the food industry. Here, we exploit a novel cinnamaldehyde (CA), eugenol (EUG), or carvacrol (CAR) combination antifungal therapy and formulate it into nanoemulsion form to overcome lower solubility and instability of essential oil. In this study, the antifungal activity evaluation and transcriptional profile of Penicillium digitatum exposed to compound nanoemulsion were evaluated. Results showed that compound nanoemulsion had a striking inhibitory effect on P. digitatum in a dose-dependent manner. According to RNA-seq analysis, there were 2,169 differentially expressed genes (DEGs) between control and nanoemulsion-treated samples, including 1,028 downregulated and 1,141 upregulated genes. Gene Ontology (GO) analysis indicated that the DEGs were mainly involved in intracellular organelle parts of cell component: cellular respiration, proton transmembrane transport of biological process, and guanyl nucleotide-binding molecular function. KEGG analysis revealed that metabolic pathway, biosynthesis of secondary metabolites, and glyoxylate and dicarboxylate metabolism were the most highly enriched pathways for these DEGs. Taken together, we can conclude the promising antifungal activity of nanoemulsion with multiple action sites against P. digitatum. These outcomes would deepen our knowledge of the inhibitory mechanism from molecular aspects and exploit naturally, efficiently, and harmlessly antifungal agents in the citrus postharvest industry.

Transcriptomic Profile of Penicillium digitatum Reveals Novel Aspects of the Mode of Action of the Antifungal Protein AfpB

“…Several studies have shown the effect of antifungal agents on the transcriptome and/or proteome of sensitive fungi, providing clues to their mode of action. Transcriptomic studies of P. digitatum treated with essential oils revealed DEGs involved in RNA transcription and transport, ABC transporters, MAPK signaling, oxidative phosphorylation, biosynthesis of secondary metabolites, sulfur, nitrogen, fatty acid metabolism, and steroid biosynthesis ( 30 ). Similarly, Botrytis cinerea exposed to these compounds resulted in the differential expression of genes related to biosynthesis of secondary metabolites, amino acid, carbohydrate, and lipid metabolisms, as well as genes involved in transcription, replication, and genetic repair ( 31 ).…”

Study on the anti-biofilm mechanism of 1,8-cineole against Fusarium solani species complex

“…Electrons produce a proton gradient across the membrane through the electron transport chain and produce ATP to provide energy for cells. Ruopeng Yang made cinnamaldehyde, eugenol or carvacrol into a compound nanoemulsion, which exerts antifungal activity by influencing the cellular respiration and proton transmembrane biological processes ( Yang et al, 2021 ). Our data showed that the oxidative phosphorylation pathway was inhibited, in which NADH dehydrogenase (ubiquinone) (Complex I), succinate dehydrogenase (SDHB) (Complex II), cytochrome c oxidase (cox1) (Complex III), Fe-S protein 1 (NDUFS1) and other enzymes were down regulated.…”