Table 2.

Metabolites that Contribute to the Optimal Prediction Model for Freezing Tolerance.

Metabolite number	Metabolite name	C24-crosses	Col-crosses
		VIP	VIP
3	Fumaric acid	2.2143	1.4084
7	Succinic acid	2.0124	not selected
8	Fructose	1.6657	1.7774
9	Galactose	1.6557	1.9322
10	Glucose	1.6072	1.2923
13	Raffinose	2.1335	2.7135
14	Sucrose	1.0619	1.2245
18	Galactinol	1.5055	2.1000
20	Maltitol	Not selected	1.1885
21	Glycine	1.0737	Not selected
22	Proline [+CO2]	1.1567	Not selected
23	Proline	1.5450	1.3678
30	Dehydroascorbic acid dimer	1.1416	1.3948
36	Hexadecanoic acid	0.9456	Not selected
38	Itaconic acid	0.9644	Not selected
39	Ethanolamine	1.0949	Not selected
48	NA	1.6438	1.6560
50	NA	0.9593	1.2818
51	NA	0.9857	1.2442
52	NA	1.0154	Not selected
59	NA	1.0534	1.5046

Data from both non-acclimated and acclimated plants were combined. Freezing tolerance data from electrolyte leakage measurements were taken from Korn et al. (2008) (compare Supplemental Table 2). The calculations were performed separately for Col-0- and C24-crosses and included the respective parental accessions, since the LT₅₀ values for these groups were measured separately, leading to a small systematic shift in all LT₅₀ values (C24-crosses: N = 20 (including C24×Col and Col×C24); Col-crosses: N = 14). Metabolite numbers refer to the numbers in Supplemental Table 1. VIP, variable importance in the projection. Higher VIP scores indicate greater importance of the selected metabolite in the prediction model. All 59 metabolites were included in the analysis for the C24-crosses, while for the Col-crosses, tryptophan was excluded because of more than 10% missing values.