Surface rehydration kinetics
The kinetics of leaf rehydration via the surface was analyzed as
described by Guzmán-Delgado et al. (2018). Leaves treated with FC and
ABA and control leaves were allowed to slowly dehydrate to the mass
corresponding to the target Ψ and recorded prior to treatment
application. We randomly selected 25 leaves per treatment. However,
leaves that reached mass values lower than those previously recorded
were discarded. Thus, we performed measurements in 21, 22 and 25 FC, ABA
and control P. dulcis leaves, respectively, and in 18, 22 and 23
FC, ABA and control P. communis leaves, respectively. Leaves with
vacuum grease sealed petioles were individually suspended in a dark
chamber at ~22 ºC connected to an ultrasonic humidifier
producing submicron fog droplets. Leaves were taken out of the
rehydration chamber after approximately 10, 20, 30, etc. min until Ψ was
approaching to zero, and patted dry with paper towels. The mass and Ψ of
each leaf were then measured. The area and DW of the leaves were
measured after scanning and oven-drying, respectively. The cumulative
amount of absorbed water and Ψ of each leaf were plotted against time
and fit with modified exponential functions (Table 1 Supporting
Information). The apparent hydraulic resistance to flow (R) between the
water source (wet leaf surface, ΨH2Osource = 0) and
rehydrating tissues was calculated from Ohm’s equation as R = Ψ/Q, where
Q is the instantaneous flux of water into the leaf calculated as the
first derivative of the mass gain function. Confidence intervals and
tests of hypothesis were performed by residual bootstrapping with R.