Fig. 7.

A model of drought tolerance mediated by CAU1–ANAC055 and proline. Drought stress reduces CAU1 mRNA and CAU1 protein levels, and decreases the binding of CAU1 to the promoter of ANAC055 (dark grey box). This decreases histone methylation of the ANAC055 chromatin, leading to increased ANAC055 expression. The subsequent increase in P5CS1 expression leads to increased proline levels and enhanced drought tolerance. The CAU1–ANAC055 pathway (dark grey box) may play a redundant role with the CAU1–CAS pathway (light grey box) to mediate plant adaptation to drought. Dashed lines represent possible unidentified steps, or steps that have been identified but are not shown here.