TRANSCRIPTIONAL ACTIVITY OF RETROTRANSPOSONS IN OLIVE VARIETIES

Transposable elements emerge as key regulatory substrates due to their impacts on genome structure and gene activity. Especially in plants, a great part of the genome is composed of them. Retrotransposons are known to affect gene expressions in several ways. Olive, characteristic tree of the Mediterranean region, is an economically and ecologically important plant. The olive tree is also of great importance with their oil production in its fruit. The oil biosynthesis capacity differs between varieties. Despite their importance, transcriptional activity of re-trotransposons in olive has not been documented, yet. In this study, we evaluated expression profiles of 10 LTR retrotransposons in wild and cultivated olive varieties each collected at two developmental stages. We identified significant expression differences comparing the samples in terms of variety and developmental status. Moreover, expression levels are tend to be higher in wild olive. The data implied that transposable elements highly influenced the shaping of the olive genome during domestication possibly providing the ability to evolve in response to environmental conditions. We also identified adjacent genes to the LTR transposons and performed in silico analysis using transcriptome data. We discussed the possible expression impacts of transposons on fruit development and formation of oil in olive.