E. Working model for the contribution of BES1 to heat stress signaling. BES1 is de-phosphorylated and activated by heat stress, utilizing ABI1 and redundant ABA-repressed PP2C phosphatases. It then interacts with HSFA1s, which are also activated by heat, for binding to HSEs in promoters of HSP70s and HSP90s genes, which induces them and increases heat stress resistance. BRs, while not needed for the activity, can promote it. 