Identification and Gene Expression Analysis of TIR1 in Easy and Hard to Root Olive (Olea europaea L.) Cultivars

Many plant species can be efficiently propagated vegetatively through the use of cuttings. Although simple to implement, the success rate of this method is restricted by the plants ability to produce adventitious roots. Auxin hormones are commonly used to induce adventitious roots in propagation by cuttings. The auxin metabolism influences plant growth and is significant because it can also affect the rooting performance of the IBA hormone commonly used during steel production. Olive trees (Olea europaea L.) are among the species that are commonly propagated using cuttings. However, the rooting success of olive cultivars grown for agriculture varies. For these reasons we analyzed the gene structure and expression rates of Olive TIR1, which is the receptor of auxins. We chose Gemlik (easy to root) and Domat (Hard to root) cultivars for the gene expression analysis. Our analysis revealed that OeTIR1 is coded by Oeu047472.1 and it contains 3 exons and codes for 594 amino acid protein and a coding sequence of 1785 nucleotides. Gene expression results showed different expression patterns between cultivars. Results indicate that in Gemlik cultivar expression of OeTIR1 does not show any upregulation after IBA application. Domat however showed an increase in expression only after 7 days