2.2. Exudate collection
The period for collecting the exudates began 30min after
switching on the lights of the growth chamber. At the end of the
water stress period, plants were de-topped 1cm above the
transition zone, and pieces of tightly fitting latex tubing were affixed to the cut stumps (Quintero et al.,1999). In the experiment in which the plants were grown in the perlite substrate, plenty of