The expression of CBF genes at Fr-2 locus is associated with the level of frost tolerance in Bulgarian winter wheat cultivars

Figures & data

Table 1. Sampling scheme of crown tissue.

Time from initiation of cold treatment	Temperature
0 (control sample) start of the acclimation	22 °С/16 °С
30 min	2 °С
1 h	2 °С
2 h	2 °С
4 h	2 °С
7 h (end of the acclimation)	2 °С
24 h (end of the de-acclimation)	22 °С

Table 2. Primers used in qRT-PCR.

Genes	Primers	Sequence	Amplicon (bp)
TaCBFIIId-15.2	F	5′-GATGACGGAAGCTGTAGCCAAT-3′	102
	R	5′-AAACATTCCGTCGCCAGAAG-3′
	Probe	5′-TACCGGCTCGTCGTG-3′
TaCBFIIId-A19	F	5′-GCCTCTGGAGCTACTGATGTCTG-3′	68
	R	5′-CAATCGGGATAGCAAAAATCCTC-3′
	Probe	5′-ACCTCCAGTGGGTTC-3′
TaCBFIVa-A2	F	5′-GCCGGAAGCCGGAGTTA-3′	61
	R	5′-CCGCCATCTGGGCACT-3′
	Probe	5′-TCTGGCTTGGCACCT-3′
TaCBFIVb-D21	F	5′-TCATCGGAGCCCCAATCA-3′	56
	R	5′-CGTGCGTTAAGCCGTTGTG-3′
	Probe	5′-TCGAACCTCGCCAGTC-3′
wact2	F	5′-CGTGTTGGATTCTGGTGATG-3′	87
	R	5′-AAGGTCAAGACGAAGGATGG-3′
	Probe	5′-CTGTGCCAATCTATGAAGGATATGCCC-3′

Figure 1. Frost tolerance rank (score 0–5) at −15 °С and −18 °С of two studied commercial Bulgarian wheat cultivars. Student's t-test was used to test for statistical significance (p < 0.05).

Figure 2. Quantitative RT-PCR expression analysis of TaCBF genes in highly tolerant winter cultivar Milena, susceptible winter cultivar Russalka and the frost sensitive spring cultivar CS. TaCBF15 (A); TaCBF19 (B); TaCBFA2 (C); TaCBF21 (D). Time points shown are 0 h (control condition at 22 °C); 30 min, 1 h, 2 h, 4 h, 7 h (LT stress at 2 °C); and 24 h (de-acclimation).