A Supramolecular Material for Controlling Kiwifruit Bacterial Canker

Area of Science:

• Plant Pathology
• Bacteriology
• Materials Science

Background:

• Kiwifruit bacterial canker (KBC), caused by Pseudomonas syringae pv. actinidiae (Psa), poses a significant threat to global kiwifruit cultivation.
• Current control methods for Psa are limited by bacterial resistance, environmental concerns with copper bactericides, and a lack of effective alternatives.

Purpose of the Study:

• To synthesize and evaluate a novel matrine (MT)-5-methylsalicylic acid (5-OMESA) salt (MOS) as a potential bactericide against Psa.
• To investigate the antibacterial mechanisms of MOS against Psa.
• To develop and assess a supramolecular nanocarrier formulation (MOS@HPCD) for enhanced Psa control.

Main Methods:

• Synthesis and characterization of the matrine-5-methylsalicylic acid salt (MOS).
• Antibacterial activity assays comparing MOS and thiazole copper (TC) against Psa.
• Analysis of MOS's effects on Psa cell membrane structure and its binding affinities to key proteins (FtsZ, DNA helicase).
• Encapsulation of MOS into hydroxypropyl-β-cyclodextrin (HPCD) to create MOS@HPCD nano formulation.
• In vitro and in vivo evaluation of MOS@HPCD efficacy against Psa.

Main Results:

• The synthesized MOS exhibited superior antibacterial activity against Psa compared to the commercial bactericide thiazole copper (TC).
• MOS demonstrated disruption of the Psa membrane structure and efficient cell penetration, with high affinities to Psa FtsZ protein and DNA helicase.
• The MOS@HPCD nano formulation showed improved solubility, foliar deposition, wettability, sustained release, and prolonged protection against Psa.
• MOS@HPCD significantly enhanced in vitro and in vivo control efficiencies against Psa compared to MOS alone.

Conclusions:

• The novel matrine-5-methylsalicylic acid salt (MOS) is an effective bactericide against Pseudomonas syringae pv. actinidiae (Psa).
• The supramolecular nanocarrier formulation (MOS@HPCD) offers superior properties and enhanced efficacy for controlling kiwifruit bacterial canker (KBC).
• MOS@HPCD represents a promising new strategy for sustainable and effective management of KBC in kiwifruit cultivation.