CDK8 integrates jasmonate signaling with sulfur availability to optimize plant chemical defense

The induced biosynthesis of these compounds is triggered by the jasmonate signaling pathway and is often associated with growth penalties. How plants coordinate growth-defense balance with nutrient availability remains poorly understood.

Here, we identify CYCLIN-DEPENDENT KINASE 8 (CDK8) as a transcriptional regulator that inhibits growth and seed yield at high levels of jasmonate defense. Transcript and metabolite profiling demonstrated that CDK8 amplifies jasmonate-triggered immunity, including the deployment of sulfur-containing defense compounds. Under sulfur-replete conditions, CDK8 promoted robust accumulation of sulfur-rich defensin peptides and sulfur-containing metabolites such as camalexin.