Fig. 9: Working model depicting that OsPRMT6b-R10 balances plant growth and high-temperature stress tolerance.

Ambient stresses like high temperature around mid-day promote ABA biosynthesis. This increased ABA binds to ABA receptors such as R10 to activate the ABA signaling pathway for adaptation to high temperature stress. ABA signaling in the WT induces expression of OsPRMT6b to methylate ABA receptors such as R10, rendering their ubiquitination and degradation. Decrease of ABA signaling to recover normal plant growth occurs when the ambient temperature falls to a normal level for plant growth. R10 cannot be methylated in the osprmt6b mutant, and the ABA signaling pathway remains activated, thus inhibiting plant growth and seed germination.