Improving the adventitious rooting ability of hard-to-root olive (Olea europaea L.) cultivar cuttings through inhibiting strigolactone biosynthesis

Abstract

Strigolactones (SLs) are synthesized in roots and control plant development. As phytohormones, SLs regulate plant architecture, including roots. Recently, the inhibiting effects of SLs on the adventitious rooting have been identified. Olive (Olea europaea L.) is consumed for oil and table in Mediterranean countries and is an economically important crop. Turkey is one of the countries with the highest olive production. Olive is mostly propagated asexually via cuttings, however the rooting capacities of some agriculturally important olive cultivars is very low. Indole Butyric Acid (IBA) is commonly used to promote rooting of the olive cuttings, however it can be inadequate. Ayvalık is an easy-to-root cultivar and one of the most common cultivars grown for oil production and Domat is a hard-to-root cultivar which IBA is insufficient for inducing rooting. In our study, the effects of synthetic SLs rac-GR24 and SLs biosynthesis inhibitor TIS108 on the rooting ability of olive cuttings were investigated. As a result, the adventitious rooting ability was increased when a hard to root cultivar was treated with TIS108, indicating a promising future for olive cutting rooting. Therefore, our study will provide potentially new tools for propagation strategies using SLs in fruit trees.

Production of secondary metabolites using tissue culture-based biotechnological applications

“…Callus formation can be induced using explants from stems, anthers, fruits, apical regions, leaves, roots, flowers, or seeds ( Patra et al., 2020 ). Vascular cambia, storage organs, pericycle of roots, endosperm, cotyledons, leaf mesophyll, and pro vascular tissue are the tissues used for callus production under in vitro culture conditions via induction ( Torres, 2012 ; Patra et al., 2020 ; Ozbilen et al, 2022 ). Although sometimes seen that liquid medium is used, the solid medium is generally used for callus growth.…”

“…While some of these secondary compounds can be very selectively produced in floral tissues to attract pollinators, some can be synthesized in roots or in leaf tissues for defense purposes ( Ritmejeryte et al., 2020 ; Jasuja, 2022 ). Some derivatives of these secondary metabolites are vital for plant growth as they form hormones such as auxins, brassinosteroids, gibberellins, and strigolactones ( Mihalache et al., 2015 ; Chopra and Samuel, 2020 ; Sathyanathan and Varadarajan, 2021 ; Waratadar et al., 2021 ; Ozbilen et al, 2022 ).…”