Extracellular self-DNA induced a PTI-related local defence against Rhizopus rot in postharvest peach fruit

作者：Li, Chunhong; Wang, Kaituo^*; Zou, Yanyu; Lei, Changyi; Chen, Zongxiang; Zheng, Yonghua

来源：Postharvest Biology and Technology, 2023, 200: 112306.

DOI：10.1016/j.postharvbio.2023.112306

• Self-DNA
• DAMP
• MAPK cascade
• Induced systemic resistance
• Prunus persica

The plant immune response against various pathogens relies on a convoluted recognition system based on perceiving exogenous or endogenous stimuli, such as pathogen-or damage-associated molecular patterns (PAMPs or DAMPs). Extracellular self-DNA (sDNA) is an established DAMP source, but the plant intracellular signaling mechanism after sDNA perception remains largely unclear. Here, we observed that peach fruit was more resistant to the fungus Rhizopus stolonifer after sDNA perception. We identified a complete MAPK cascade (MAPKKK1, MAPKK2 and MAPK1) that functions downstream of the FLS2-BAK1 receptor complex following the perception of sDNA-derived DAMPs by means of transcriptome sequencing. The results of yeast two-hybrid (Y2H) and glutathione S-transferase (GST) pull-down assays confirmed the protein interaction of FLS2 and BAK1; meanwhile, the interaction of MAPKKK1 and MAPKK2 and its downstream interaction of MAPKK2 and MAPK1 were both exhibited following the another Y2H results. Accordingly, MAPK1 interacted with 1-amino-cyclopropane-1-carboxylate oxidase (ACO1), which was directly associated with increased ethylene produc-tion and upregulation of the transcription profile of ethylene synthesis-related genes (PpSAMDC, PpACS1 and PpACO1), ethylene receptors (ETRs and ERS1), ethylene-responsive transcription factors (ERFs) and three ethylene-inducible marker genes, PLANT DEFENSIN1.2 (PDF1.2), CHITINASE (CHI) and HOOKLESS1 (HLS1). Accordingly, the overexpression of MAPK1 enhanced the disease resistance of transgenic tomato against the fungus R. stolonifer and increased ethylene biosynthesis and ethylene signaling-related gene transcription. Taken together, our data provide insight into the putative mechanism underlying the recognition of sDNA components by the FLS2-BAK1 complex and its downstream events in the transduction of ethylene signaling by the MAPK cascade to mediate local resistance in postharvest peach fruit.

• 单位
  南京农业大学