Helium Atmospheric‐Pressure Plasma Jet Enables Macromolecule Introduction in Tomato Stem Sections While Maintaining Short‐Term Graft Adhesion

ABSTRACT The delivery of functional molecules at the graft interface could overcome plant graft incompatibility. This study uses an in vitro micrografting (IVG) system to verify whether introducing molecules at the stem cross‐section using a low‐temperature atmospheric‐pressure plasma jet (APPJ) is compatible with grafting. After a 15‐s APPJ treatment, fluorescein diacetate staining confirms high cell viability. The treatment introduces 10‐kDa FITC–dextran but not 2 MDa dextran owing to the plant cell wall's pore size limitation. Quantitative adhesion force measurements show that APPJ treatment does not considerably inhibit graft adhesion. These results indicate that APPJ can be used to deliver molecules to the stem cross‐section without impairing the initial mechanical adhesion of the graft union.