title: Transcriptional profiling analysis of Penicillium digitatum, the causal agent of citrus green mold, unravels an inhibited ergosterol biosynthesis pathway in response to citral.
abstract: Green 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.
  
  
  
  In 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.
  
  
  
  Our present finding suggests that citral could exhibit its antifungal activity against P. digitatum by the down-regulation of ergosterol biosynthesis.
authors: School of Chemical Engineering, Xiangtan University, Xiangtan, 411105, People's Republic of China.
authors: Qiuli
authors: Q
authors: OuYang
authors: School of Chemical Engineering, Xiangtan University, Xiangtan, 411105, People's Republic of China. nengguotao@126.com.
authors: Nengguo
authors: N
authors: Tao
authors: School of Chemical Engineering, Xiangtan University, Xiangtan, 411105, People's Republic of China.
authors: Guoxing
authors: G
authors: Jing
mesh_terms: D000080462:Acyclic Monoterpenes; D002957:Citrus / Q000382:microbiology; D004875:Ergosterol / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D005656:Fungal Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D005659:Fungicides, Industrial / Q000494:pharmacology*; D008401:Gas Chromatography-Mass Spectrometry; D020869:Gene Expression Profiling; D015966:Gene Expression Regulation, Fungal; D007810:Lanosterol / Q000819:agonists / Q000096:biosynthesis; D053858:Metabolic Networks and Pathways / Q000187:drug effects / Q000235:genetics; D008826:Microbial Sensitivity Tests; D039821:Monoterpenes / Q000494:pharmacology*; D025282:Mycelium / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D010407:Penicillium / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D010935:Plant Diseases / Q000517:prevention & control; D012331:RNA, Fungal / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D017423:Sequence Analysis, RNA; D058886:Sterol 14-Demethylase / Q000235:genetics / Q000378:metabolism; D059467:Transcriptome / Q000187:drug effects
chemical_list: D000080462:Acyclic Monoterpenes; D005656:Fungal Proteins; D005659:Fungicides, Industrial; D039821:Monoterpenes; D012331:RNA, Fungal; D007810:Lanosterol; D058886:Sterol 14-Demethylase; C007076:citral; D004875:Ergosterol
keywords: Citral; Ergosterol biosynthesis; Penicillium digitatum; RNA-Seq