Parameter	Example standardizations
	Phaseolus vulgaris	Solanum lycopersicum	Arabidopsis thaliana
Leaf type	First true leaves, fully expanded, healthy	2nd and 3rd leaves starting from bottom, 4 largest leaflets taken apical leaflet not used for apoplast extraction	Fully expanded rosette leaves
Plant age	21 days	7 - 9 weeks	7 weeks
Time of day	Middle of light period (12:00)	Middle of light period (12:00)	Middle of light period (12:00)
Hydration	All plants well watered 1 hr pre-harvest	All plants well watered 1 hr pre-harvest	All plants well watered 1 hr pre-harvest
Light	16 hr light, 400 µmol m-2 sec-1	16 hr light, 400 µmol m-2 sec-1	10 hr light (short day) from week 2, 400 µmol m-2 sec-1
Humidity	70%	70%	70%
Temperature	22 °C light, 18 °C dark	22 °C light, 18 °C dark	21 °C