The formation of secondary cell walls is tightly regulated
spatio-temporally by various developmental and environmental signals.
Successful fine-tuning of the trade-off between secondary cell wall
biosynthesis and stress responses requires better understanding of how
plant growth is regulated under environmental stress conditions.
However, current understanding of the interplay between environmental
signaling and secondary cell wall formation is limited. The
lipid-derived plant hormone jasmonate (JA) and its derivatives are
important signaling components involved in various physiological
processes including plant growth, development, and abiotic/biotic stress
response. Recent studies suggest that JA may be involved in secondary
cell wall formation. We tested this hypothesis using the transcription
factor MYB46, a master switch for secondary wall biosynthesis, and JA
treatments. Both the transcripts and protein levels of MYB46 were
significantly increased by the JA treatments, which also triggered the
upregulation of MYB46 downstream genes with increased secondary wall
formation. We then show that this JA-induced upregulation of MYB46
function was mediated by MYC2, a basic helix-loop-helix (bHLH)
domain–containing transcription factor, which plays a pivotal role in
the JA-mediated changes. We conclude that this MYC2-MYB46 module is a
key component of the plant response to JA signaling.