Effect of pre-existing embolism on embolism resistance in leaves
In the leaves of L. benzoin , in which only 20% of embolism was observed, mostly in the mid-rib, rehydration ceased the spread of embolism, and on a second period of dehydration, embolism only formed once Ψ had declined to the values just prior to rehydration. In contrast in a leaf rehydrated when 35% of the xylem had embolized, rehydration was much less effective at reducing the spread of embolism on a second round of dehydration. These results suggest that the xylem of angiosperm leaves may be more susceptible to air invasion from embolism in neighbouring conduits or intercellular air spaces, than stems, although more work is required to address this possibility (Guan et al. 2021).