Plant fitness and survival depend on the ability and plasticity to adapt developmental and growth

programmes to a 24-hour changing environment, which is safeguarded by complex signalling

networks in which hormones such as the jasmonates play major roles. The bioactive version of the

jasmonate hormone is perceived by the co-receptor complex consisting of the F-box protein

CORONATINE 1 (COI1) and a JAZ repressor protein. Whereas our knowledge on the (post)

transcriptional and (post)translational regulation of the abundance of JAZ proteins is rapidly

increasing, very little is known on the regulation of COI1 levels and activity, let alone on the

molecular mechanisms by which plant cells regulate and maintain the required COI1 levels to

properly execute its biological function. This important gap in our knowledge on how JA signalling is

controlled will be addressed in this research project. We will carry out yeast-one hybrid screens and

transactivation assays with the COI1 promoter to identify regulators of COI1 transcription, analyse

the function of small upstream open reading frames in the COI1 transcript, and perform affinity

purifications with tagged COI1 proteins to identify regulators of COI1 stability and activity.

Subsequent in-depth functional analysis of the identified COI1 regulators will establish their role in

JA signalling and determine whether they may play pleiotropic roles in the regulation of

phytohormone receptor abundance and functioning.