Linear glandular trichomes of sunflower - characterization of their distribution, development, metabolite profile and terpenoidspecific transcriptome"

• Applicant: Professor Dr. Otmar Spring
• Subject Area: Plant Biochemistry and Biophysics
• Term: from 2011 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 206698716

The development and biosynthetic activity of glandular trichomes in Asteraceae has yet been studied with entire focus on the capitate glands. But the epidermal surface of sunflower bears a second type of hairs composed of uniserial arranged cells. Their mode of secretion, chemical composition and ecological function is entirely different, but mostly uninvestigated. Up to now only the trichome specific storage of bisabolene-type sesquiterpenes in these linear glandular trichomes (LGT) was shown, but little is known on their biosynthetic activity and development in general. The proposed project will explore the distribution of LGT in Helianthus, clarify the occurrence and document the development. Microscopy, HPLC and molecular genetic techniques will be used for metabolome and transcriptome analysis to unravel the secretion of sesquiterpenes and identify enzymes involved in their production. As a proof of concept, a first LGT-specific germacrane synthase was recently identified in this way. Conserved motives of known terpene synthases will be used to trace candidate genes in the RNA pool of LGT with focus on putative bisabolene synthases. Identified enzymes will be expressed and characterised. The results will provide key information for this new type of trichome.

• DFG Programme: Research Grants