Exposure of potato (Solanum tuberosum L.) to biotic stress results in altered expression of genes that respond to stress by activating or deactivating binding of transcription factors to cis-regulatory elements. In this master's thesis, we analysed the CPI8 gene promoter to determine a cis-regulatory element, or a combination of several elements, crucial for the response to jasmonic acid (JA), which is synthesized during stresses such as mechanical tissue damage and Colorado potato beetle infestation (Leptinotarsa decemlineata). First, we truncated the sequence of the promoter variant from potato genotype Désirée, pCPI8.De7, on its 3’ and 5’ end using polymerase chain reaction (PCR) to gradually exclude predicted JA responsive cis-regulatory elements. We fused the truncated versions of pCPI8.De7 to the coding sequence of the reporter protein luciferase. We then performed transient transformation of potato and tobacco (Nicotiana benthamiana Domin) plants and measured luminescence after addition of luciferin and JA. Results showed that potato is not suitable for such an assay. On the other hand, using luciferase assays on tobacco, we identified a section in the CPI8.De7 promoter that is crucial for the response to JA. Using mutagenic PCR, we further truncated this section and introduced several point mutations and discovered that most likely, the combination of binding sites for the transcription factors VIP1 and NAC078 and a yet unknown
cis-regulatory element is indispensable for the response of pCPI8.De7 to JA. These elements could be used to develop a genetically encoded biosensor for JA that would enable a better understanding of stress defense mechanisms in potato.
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