Table II. Targeted MS treatment conditions.

Treatment conditions were used for targeted proteomic analysis of 58 phosphopeptides.

Treatment	Concentration	Rationale
Mannitol	300 mm	Osmotic stress, validation of discovery results
NaCl	150 mm	Ionic stress, osmotic stress
KCl	150 mm	Plasma membrane depolarization, osmotic stress
S-ABA	50 μm	Drought stress hormone
Cold	0°C–4°C	Freezing tolerance overlap with dehydration stress; overlapping second messengers with osmotic stress
Flg22	1 μm	Pathogen elicitor; overlapping second messengers with osmotic stress
H2O2	5 mm	ROS, second messenger
Fusicoccin	5 μm	Plasma membrane hyperpolarization
Methyl jasmonate	50 μm	Defense response hormone; minimal overlap expected