Transcriptional profiling analysis of Penicillium digitatum, the causal agent of citrus green mold, unravels an inhibited ergosterol biosynthesis pathway in response to citral

Abstract

BackgroundGreen mold caused by Penicillium digitatum is the most damaging postharvest diseases of citrus fruit. Previously, we have observed that citral dose-dependently inhibited the mycelial growth of P. digitatum, with the minimum inhibitory concentration (MIC) of 1.78 mg/mL, but the underlying molecular mechanism is barely understood.ResultsIn this study, the transcriptional profiling of the control and 1/2MIC-citral treated P. digitatum mycelia after 30 min of exposure were analyzed by RNA-Seq. A total of 6355 genes, including 2322 up-regulated and 4033 down-regulated genes, were found to be responsive to citral. These genes were mapped to 155 KEGG pathways, mainly concerning mRNA surveillance, RNA polymerase, RNA transport, aminoacyl-tRNA biosynthesis, ABC transporter, glycolysis/gluconeogenesis, citrate cycle, oxidative phosphorylation, sulfur metabolism, nitrogen metabolism, inositol phosphate metabolism, fatty acid biosynthesis, unsaturated fatty acids biosynthesis, fatty acid metabolism, and steroid biosynthesis. Particularly, citral exposure affected the expression levels of five ergosterol biosynthetic genes (e.g. ERG7, ERG11, ERG6, ERG3 and ERG5), which corresponds well with the GC-MS results, the reduction in ergosterol content, and accumulation of massive lanosterol. In addition, ERG11, the gene responsible for lanosterol 14α-demethylase, was observed to be the key down-regulated gene in response to citral.ConclusionOur present finding suggests that citral could exhibit its antifungal activity against P. digitatum by the down-regulation of ergosterol biosynthesis.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-016-2943-4) contains supplementary material, which is available to authorized users.

Transcriptome analysis of fungicide-responsive gene expression profiles in two Penicillium italicum strains with different response to the sterol demethylation inhibitor (DMI) fungicide prochloraz

“…Fungal resistance to DMIs can also be ascribed to overexpression of CYP51s, especially by some enhancer elements [9,[27][28][29][30][31][32][33]. In addition to CYP51s, recently, other genes encoding fungal ergosterol biosynthesis-related enzymes have been proposed to be potential targets, including ERG2 (encoding C − 8 sterol isomerase) [34][35][36] and ERG6 (encoding C − 24 sterol methyltransferase) [37][38][39][40]. The importance of both ERG2 and ERG6 to cycloheximide resistance for S. cerevisiae has also been genetically emphasized [41].…”

Stereoselective bioactivity, toxicity and degradation of the chiral triazole fungicide bitertanol

“…The four stereoisomers concentrations were the EC 10 , EC 50 , and EC 90 values that were obtained from the 2.2 section. Ergosterol was extracted and determined according to prior references . The mycelia were collected by filtration and washed with sterile water, and the mycelia were dried in a vacuum freeze, then the dried mycelia were grinded in liquid nitrogen.…”

“…Ergosterol was extracted and determined according to prior references. [15][16][17] The mycelia were collected by filtration and washed with sterile water, and the mycelia were dried in a vacuum freeze, then the dried mycelia were grinded in liquid nitrogen. Next, 0.15 g of mycelia was added into a 50 mL centrifuge tube with 10 mL methanol-chloroform (3:1 V/V) and the solution was allowed to stand for 12 h at 60 ∘ C. A mixture of 10 mL of distilled water, chloroform, and phosphoric acid buffer containing KCl was added; subsequently, the chloroform solution was transferred to another tube and flushed with nitrogen until dry.…”

Determination of metabolites of Geotrichum citri-aurantii treated with peppermint oil using liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry

“…Some of these diseases originate from infections initially occurring in the fields, and the others are caused by subsequent processing wounds . In recent years, with the strengthening of the prevention and control of green mold and blue mold, sour rot has gradually become one of the most common diseases in the process of storage and transportation of citrus, and there is no clear and effective means of prevention and control until now (Boubaker et al, ; Karim et al, ; OuYang, Tao, & Jing, ; Talibi, Boubaker, Boudyach, & Ait Ben Aoumar, ). Sour rot is a leading disease of citrus fruit caused by the postharvest pathogen G. citri‐aurantii , and it is partially prevented by sanitation control and low‐temperature storage.…”

“…mold and blue mold, sour rot has gradually become one of the most common diseases in the process of storage and transportation of citrus, and there is no clear and effective means of prevention and control until now Karim et al, 2016;OuYang, Tao, & Jing, 2016;Talibi, Boubaker, Boudyach, & Ait Ben Aoumar, 2014).…”