Antifungal Activity of β-Carboline Alkaloids Compound and Its Resistance Mechanism on <i>Peronophythora Litchii</i>

Peronophythora litchii (P. litchii) is the pathogenic factor of litchi downy blight. Derivatives extracted from harmine officinalis and modified, N-(2-pyridyl)-1-phenyl-9 H-pyrido [3, 4-b] indole-3-formamide (PPPIF), could inhibited P. growth development. Scanning Electron Microscopy (SEM) Transmission (TEM) analyses indicated that PPPIF severely damaged mitochondria, cell wall endomembrane system cells, thus abnormal morphology, as well deformed mycelia. suppress mycelial growth, sporulation, sporangia germination germ tube elongation well. also caused a series physiological biochemical changes litchii, including serious deviation extracellular pH, obvious increase content reducing sugar malondialdehyde, notable decrease soluble protein activity NADH oxidase. Furthermore, seriously raised openness membrane permeability transporter (MPTP) markedly decreased transmembrane potential (Δψm) enzyme complex I–complex V in respiratory chain mitochondria. The current research suggests may act upon mitochondrion then was blocked energy metabolism disrupted or inhibited, resulting inhibition litchii. Above results have strengthened our understanding resistance mechanisms help development more potent inhibitors against plant diseases fields.