Transcriptomic Response inPseudomonas aeruginosatowards Treatment with a Kaempferol Isolated fromMelastoma malabathricumLinn Leaves

Abstract

Pseudomonas aeruginosais one of the main causes of nosocomial infections and is frequently associated with opportunistic infections among hospitalized patients. Kaempferol-3-O-(2′,6′-di-O-trans-p-coumaroyl)-β-D glucopyranoside (KF) is an antipseudomonal compound isolated from the leaves of the native medicinal plantMelastoma malabathricum. Herein, an RNA-seq transcriptomic approach was employed to study the effect ofKFtreatment onP. aeruginosaand to elucidate the molecular mechanisms underlying the response toKFat two time points (6 h and 24 h incubation). Quantitative real-time PCR (qRT-PCR) was performed for four genes (uvrD,sodM,fumC1, andrpsL) to assess the reliability of the RNA-seq results. The RNA-seq transcriptomic analysis revealed thatKFincreases the expression of genes involved in the electron transport chain (NADH-I), resulting in the induction of ATP synthesis. Furthermore,KFalso increased the expression of genes associated with ATP-binding cassette transporters, flagella, type III secretion system proteins, and DNA replication and repair, which may further influence nutrient uptake, motility, and growth. The results also revealed thatKFdecreased the expression of a broad range of virulence factors associated with LPS biosynthesis, iron homeostasis, cytotoxic pigment pyocyanin production, and motility and adhesion that are representative of an acuteP. aeruginosainfection profile. In addition,P. aeruginosapathways for amino acid synthesis and membrane lipid composition were modified to adapt toKFtreatment. Overall, the present research provides a detailed view ofP. aeruginosaadaptation and behaviour in response toKFand highlights the possible therapeutic approach of using plants to combatP. aeruginosainfections.