Alterations in the transcript level of HSFs, HSFA4A
(a), HSFA3
(b), HSF4
(c) in the leaves of Heliotropium thermophilum growing in soil at 20 ± 5 °C, 40 ± 5 °C, 60 ± 5 °C and 80 ± 5 °C. Vertical bars represent standard deviations of the means of three replicates. Different letters denote significant differences among all treatments at P < 0.05