Figure 4. Heat shock factors are necessary for ONSEN activation by heat stress.

Relative amounts of ONSEN RNA and extrachromosomal DNA prepared from three week-old, non-stressed or 30 h HS treated seedlings of wild type Wassilewskija (WT2, background of the mutants), triple or quadruple mutants lacking three or all functional HSFA1 proteins (A, B, D, E). RNA and exDNA were determined by quantitative RT-PCR and densitometry after Southern blot analysis as described before (n = 3).