Table 1. Proteins with Increased Phosphopeptide Abundance in egr1-1 egr2-1 Relative to the Wild Type.

Protein ID	Phosphopeptide Ratio WT Stress/WT Control	P Value (WT)	Phosphopeptide Ratio egr1-1 egr2-1 Control/WT Control	P Value (Cont.)	Phosphopeptide Ratio egr1-1 egr2-1 Stress/WT Stress	P Value (Stress)	Description
			Increased phosphopeptide abundance in egr1-1 egr2-1 in stress treatment
AT4G03260	4.4	0.13	1.8	0.20	8.2	0.07	MASP1
AT5G59790	1.0	1.00	1.2	0.70	2.3	0.02	Unknown (DUF 966)
AT2G41740	1.5	0.58	1.5	0.45	1.9	0.04	Villin 2 (VLN2)
AT1G65030	1.2	0.76	2.6	0.27	1.9	0.03	DWD motif, part of CUL4-based E3 ubiquitin ligase
AT1G71710	1.1	0.93	−1.4	0.58	1.7	0.01	Inositol-polyphosphate 5-phosphatase
AT5G63640	1.1	0.30	1.1	0.73	1.6	0.03	ENTH/VHS/GAT family
			Increased phosphopeptide abundance in egr2-1 egr2-1 in control
AT1G70180	6.6	0.07	2.2	0.05	−1.2	0.65	Sterile alpha motif (SAM)
AT2G40070	2.1	0.29	2.0	0.01	−1.3	0.41	Basic proline-rich protein (BPP1)
AT3G53180	4.8	0.04	1.7	0.05	1.3	0.43	Nodulin/Glutamine Synthase-Like (NodGS)
AT3G01810	1.4	0.56	1.7	0.02	−1.4	0.27	Unknown protein
AT2G32060	1.2	0.56	1.7	0.03	1.3	0.54	Ribosomal protein L7Ae/L30e/S12e/Gadd45
AT5G38600	1.1	0.89	1.6	0.01	1.0	0.83	Proline-rich spliceosome-associated (PSP) protein
AT1G19870	1.6	0.10	1.6	0.04	1.1	0.75	IQ-domain 32 (IQD32)
AT5G52310	14.1	0.07	1.5	0.05	1.3	0.43	Responsive to Desiccation29A (RD29A)
AT3G46780	1.2	0.35	1.5	0.01	1.0	0.97	Plastid transcriptionally active 16 (PTAC16)
AT3G47070	−2.9	0.27	1.5	0.05	1.1	0.67	Thylakoid soluble phosphoprotein TSP9
AT1G17210	2.8	0.16	1.5	0.01	1.3	0.01	IAP-like protein 1 (ILP1), phragmoplast associated

A 1.5-fold increase and P value ≤ 0.05 (by one-sided t test) were the criteria to define putative EGR-regulated phosphoproteins (MASP1 is also included based on our further characterization of it). Significant fold increases are indicated by bold numbers. Additional data on phosphopeptide sequences as well as accompanying gene expression data can be found in Supplemental Data Set 8. WT, wild type.