Poster: Intracellular Signaling

Abs # 850: A screen for genes involved in UV-B / blue light induction of Arabidopsis chalcone synthase reported via a luciferase transgene

Presenter:	Littlejohn, George R. , 9403985l@udcf.gla.ac.uk
Authors	Littlejohn, George R.  (A)   Jenkins, Gareth I.  (A)
Affiliations:	(A): Plant Science Group, Division of Biochemistry and Molecular Biology, IBLS, University of Glasgow, Glasgow, UK.

Chalcone synthase (CHS) is an important enzyme in plant secondary metabolism, and is the first committed step in the production of flavonoids. Flavonoids have diverse functions in plants ranging from phytoprotection to pollen maturation. In Arabidopsis thaliana, CHS is present as a single copy gene, with the expression of functional CHS protein being controlled at the level of transcription, which makes it a good model for studying gene expression. CHS is activated via a number of abiotic and biotic stresses, including various light qualities. In mature leaf epidermis, CHS expression is elevated upon exposure to blue or UV-B light. Although both these light qualities will induce CHS when given alone, they induce CHS synergistically (i.e. to an extent that is greater than additive) when given coincidentally, or sequentially (with blue illumination, followed by UV-B illumination). This suggests that there is crosstalk between the UV-B and blue light signalling pathways. Using a CHS promoter : luciferase reporter construct to assay CHS expression in planta, we are screening an EMS mutagenised population for individuals altered in the synergistic induction of CHS by blue and UV-B light.