NMR-based metabolic study of leaves of three species of Actinidia with different degrees of susceptibility to Pseudomonas syringae pv. actinidiae

Abstract

Bacterial canker of Actinidia, caused by the bacterium Pseudomonas syringae pv. actinidiae (Psa), is the most serious disease of these plants worldwide. Leaves of three species of Actinidia, namely A. chinensis var. chinensis, A. chinensis var. deliciosa and A. arguta, having different degrees of tolerance to Psa, were analyzed by Nuclear Magnetic Resonance spectroscopy. Aqueous extracts of leaves were studied and several metabolites, classified as organic acids, amino acids, carbohydrates, phenols and other metabolites, were identified by 1D and 2D NMR experiments and quantified. The metabolic profiles of these species were compared through univariate statistical analysis ANOVA and multivariate PCA. Levels of metabolites with known antibacterial activity, such as caffeic and chlorogenic acids, were observed to be higher in the A. arguta samples. Moreover, these metabolites have different Pearson correlation patterns among the three Actinidia species, suggesting a difference at the phenylpropanoid biosynthetic pathway.

Graphical Abstract

Keywords:

• Actinidia chinensis var. chinensis
• Actinidia chinensis var. deliciosa
• Actinidia arguta
• NMR
• metabolic profile
• Pseudomonas syringae pv. actinidiae

Disclosure statement

The authors declare no competing financial interest.

Funding

The present work has been carried out under the project “Development of high-resolution NMR methodological platforms for the determination in various plant organs of metabolites involved in susceptibility or resistance to pathogens and insects”, funded by the Italian Ministry of Agriculture and Forestry Policy [grant number CRAM 3.00.08.00].