Figure 10.

Model Summarizing JA Accumulation, Transcriptional Regulation, and Metabolic Processes Associated with Corolla Elongation and Limb Opening.

Fine-tuned JA-Ile signaling during early floral development controls N. attenuata corolla developmental progress and limb opening. Transcriptional and metabolite profiles highlight an early developmentally regulated burst in JA pools and further support a negative feedback function of JA-Ile/COR on JA biosynthesis. Increases in limb fresh mass, corolla transcript levels of MYB305 and JAZd, ABA and soluble carbohydrate levels, and the subsequent complete limb expansion are not impaired in ir-coi1. However, signaling via the JA receptor COI1 is essential for BA emission and the expression of MYB305 in floral nectaries. JA and COI1 mediate the regulation of nectary maturation and floral nectar secretion.