Table 2. Expression stability values of twelve reference genes as calculated by the NormFinder in P. praeruptorum.

Rank	PEG	NaCl	CuSO4	H2O2	MeJA	SA	Cold	Hot	Tissue	Total
1	PTBP1	SAND	UBC9	ACT2	SAND	SAND	SAND	ACT2	SAND	SAND
	0.17	0.061	0.167	0.076	0.215	0.085	0.091	0.242098	0.288	0.463
2	PP2A	TIP41	PTBP1	NCBP20	PP2A	TUB6	PTBP1	PTBP1	EF-1α	ACT2
	0.189	0.15	0.193	0.215	0.253	0.18	0.197	0.263187	0.367	0.556
3	NCBP20	ACT2	GAPDH	UBC9	UBC9	UBC9	UBC9	TIP41	NCBP20	PTBP1
	0.349	0.245	0.221	0.238	0.308	0.243	0.22	0.340158	0.435	0.566
4	CYP2	UBC9	ACT2	PP2A	PTBP1	PP2A	NCBP20	PP2A	eIF-4α	CYP2
	0.357	0.539	0.234	0.25	0.315	0.275	0.231	0.456	0.44	0.622
5	UBC9	PP2A	PP2A	PTBP1	NCBP20	EF-1α	eIF-4α	eIF-4α	CYP2	PP2A
	0.372	0.61	0.329	0.308	0.35	0.331	0.237	0.472	0.494	0.677
6	SAND	GAPDH	CYP2	EF-1α	eIF-4α	CYP2	PP2A	CYP2	ACT2	UBC9
	0.467	0.681	0.439	0.328	0.363	0.362	0.26	0.479	0.568	0.746
7	EF-1α	EF-1α	NCBP20	SAND	TIP41	ACT2	EF-1α	UBC9	UBC9	NCBP20
	0.595	0.737	0.502	0.364	0.56	0.375	0.399	0.544	0.611	0.76
8	TIP41	CYP2	TIP41	TUB6	EF-1α	NCBP20	CYP2	SAND	PTBP1	TIP41
	0.643	0.758	0.528	0.368	0.659	0.4	0.409	0.55	0.643	0.785
9	eIF-4α	PTBP1	SAND	eIF-4α	TUB6	PTBP1	ACT2	GAPDH	TUB6	EF-1α
	0.649	0.837	0.616	0.37	0.7	0.428	0.49	0.668	0.655	0.832
10	TUB6	eIF-4α	EF-1α	GAPDH	ACT2	GAPDH	GAPDH	EF-1α	PP2A	eIF-4α
	0.725	1.09	0.627	0.383	0.727	0.486	0.595	0.862	0.692	0.873
11	ACT2	NCBP20	TUB6	TIP41	CYP2	TIP41	TIP41	NCBP20	TIP41	TUB6
	0.792	1.607	0.742	0.485	0.804	0.512	0.634	1.021	0.907	0.932
12	GAPDH	TUB6	eIF-4α	CYP2	GAPDH	eIF-4α	TUB6	TUB6	GAPDH	GAPDH
	1.234	1.686	0.981	0.578	1.253	1.444	0.857	1.183	1.179	1.18