ODO1 regulates the timing of internal volatile production in Petunia hybrida, and possibly influences the volatile composition.

Data Repository Bachelor Thesis Nina Borsboom. To attract the right pollinators, <em>Petunia hybrida </em>emits its floral fragrance at night. The temporal emission of fragrance is regulated by transcription factors such as EMISSION OF BENZENOIDS I &amp; II (EOBI &amp; EOBII) and ODORANT1 (ODO1). The timed expression of <em>ODO1</em>, determines the timing of volatile emission. The expression of <em>ODO1</em> is negatively regulated by LATE ELONGATED HYPOCOTYL (LHY). LHY represses <em>ODO1</em> transcription by binding to ‘evening elements’ (EEs) in the promoter region of <em>ODO1</em>. In this study the effect of ODO1 on the production of internal volatiles and the volatile composition is researched by determining the gene expression levels of <em>ODO1</em>, <em>EPSPS1</em>, and <em>PAL1</em>. The start of the production of internal volatile compounds in different lines was also determined with a GC-MS. The used transgenic lines of <em>P. hybrida</em> contained <em>ODO1 </em>constructs with either no functional EEs, one functional EE or both functional EEs in the <em>ODO1</em> promoter region. <em>ODO1</em> is significantly earlier upregulated in lines with mutations in both EEs, which correlates with earlier production of internal volatiles when compared to wild type <em>P. hybrida</em>. Small changes in the composition of the internal volatiles were also observed.