Water potential gradient facilitated interplant transfer via Desmanthus illinoensis.

Abstract

Water potential gradients have been largely ignored as a primary factor capable of influencing interplant transfer even though there was evidence of hydraulic conductivity across the biotrophic plant fungi interface. Using two fluorescence tracer molecules, phorwite and rhodamine, a direct transfer pathway was observed and direct transfer quantified between two Illinois Bundleflower (Desmanthus illinoensis) plant root systems linked by arbuscular mycorrhizal (AM) hyphae. Three water potential gradients were tested: (i) receiver plant water-stressed -0.25 ±.03 MPa, (ii) no water stress, and (iii) donor plant water-stressed. When the receiver plant was water-stressed, rapid (< 18 h) dye transfer occurred, obeying the source/sink paradigm often utilized in other interplant nutrient transfer studies.