3 Methods
3.1 Sample
Collection
3.1.1 Exudate Collection
and Purification
1. Once the plants are between 4 and 6 weeks old at least, rinse
the pots with distilled water to collect between 100 and
200 mL of exudate from at least three different plants
(Fig. 2) (see Note 2).
2. Filter the exudate by filter paper in a Buchner funnel with
vacuum (Fig. 2).
3. Activate C18 SPE cartridges with 3 mL of MeOH.
4. Wash it with 6 mL of water.
5. Load the exudate into the cartridge.
6. Wash it with 3 mL of water and 3 mL of water:acetone 60:40
(v/v).
7. Elute SLs with 3 mL of acetone.
8. Evaporate the acetone in a rotary evaporator and store the
sample at À80
C until their analysis.
3.1.2 Root Extract
1. Once roots are collected, dry them in an oven at 40
C for 48 h.
2. Powder the dry roots in an industrial mill.
3. Extract 100 mg of roots with 1 mL of ethyl acetate in an
ultrasonic bath for 10 min.
4. Centrifuge the samples for 10 min at 5000 rpm.
Fig. 2 Exudate collection and filtration by rinsing the pots with distilled water
Quantification of Strigolactones
203