Refilling of embolised conduits as a consequence of 'Münch water' circulation

'Münch water' is pushed from the phloem to the xylem at locations of phloem sugar unloading. Consequently, an internal radial water potential imbalance is developed in the plant at these sugar-unloading sites. The phloem is at a higher water potential than the xylem. The magnitude of this radial water potential imbalance is determined by the magnitude of the radial water flux and the hydraulic resistance along the phloem-to-xylem pathway. If, as a result, the water potential in the ray parenchyma cells adjacent to xylem conduits is higher than that in the embolised xylem conduits, then a proportion of the water flow from the phloem would be directed towards embolised xylem conduits, in addition to conduits under tension. In this theoretical paper we demonstrate how recycled 'Münch water' passing from the phloem to the xylem can induce xylem embolism refilling. We also calculate the conditions and the structural composition of the phloem-to-xylem pathway that are required for embolism refilling by 'Münch water' circulation, and the time that is required for the complete refilling of embolised conduits in varying conditions.