Anti‐oomycete ability of scopolamine against Phytophthora infestans, a terrible pathogen of potato late blight

Abstract

BACKGROUNDPhytophthora infestans causes late blight, threatening potato production. The tropane alkaloid scopolamine from some industrial plants (Datura, Atropa, etc.) has a broad‐spectrum bacteriostatic effect, but its effect on P. infestans is unknown.RESULTSIn the present study, scopolamine inhibited the mycelial growth of phytopathogenic oomycete P. infestans, and the half‐maximal inhibitory concentration (IC50) was 4.25 g L−1. The sporangia germination rates were 61.43%, 16.16%, and 3.99% at concentrations of zero (control), 0.5 IC50, and IC50, respectively. The sporangia viability of P. infestans was significantly reduced after scopolamine treatment through propidium iodide and fluorescein diacetate staining, speculating that scopolamine destroyed cell membrane integrity. The detached potato tuber experiment demonstrated that scopolamine lessened the pathogenicity of P. infestans in potato tubers. Under stress conditions, scopolamine showed good inhibition of P. infestans, indicating that scopolamine could be used in multiple adverse conditions. The combination effect of scopolamine and the chemical pesticide Infinito on P. infestans was more effective than the use of scopolamine or Infinito alone. Moreover, transcriptome analysis suggested that scopolamine leaded to a downregulation of most P. infestans genes, functioning in cell growth, cell metabolism, and pathogenicity.CONCLUSIONTo our knowledge, this is the first study to detect scopolamine inhibitory activity against P. infestans. Also, our findings highlight the potential of scopolamine as an eco‐friendly option for controlling late blight in the future. © 2023 Society of Chemical Industry.

Endophytic Bacillus subtilis H17‐16 effectively inhibits Phytophthora infestans, the pathogen of potato late blight, and its potential application

“…The potential of H17-16 combined with chitosan or fungicide to control potato late blight Infinito is the most commonly used and effective chemical fungicide in the control of potato late blight. 74 The tolerance of H17-16 to fungicide was preliminarily identified by the detection of H17-16 growing on the medium containing infinito. No matter whether the concentration of infinito was 1 mL/L (the field application concentration) or 10 mL/L, H17-16 grew well, implicating infinito does not affect the growth of H17-16 (Table S10).…”

Secondary Metabolites, Other Prospective Substances, and Alternative Approaches That Could Promote Resistance against Phytophthora infestans

“…In summary, solanidine is a prospective marker for genotypes with attenuated glycoalkaloid production, e.g., genotypes with a limited conversion of solanidine to solanine and a total alkaloid content within the safety limits. A recent study showed that tropane alkaloid scopolamine inhibits sporangia germination and viability, and that its application could promote the effects of a chemical pesticide [152]. This alkaloid is found in some members of Solanaceae, but given its infamous reputation, it is unlikely that it would find a large-scale application in agriculture.…”