Expression of auxin carrier genes during adventitious rooting in Eucalyptus globulus

Background Eucalyptus globulus and its hybrids are important for the cellulose and paper industry, mainly due to their relatively low lignin content. However, rooting of cuttings of this species is often recalcitrant and exogenous auxin application is necessary for adventitious root development. Auxin plays a central role in rooting capacity, which is particularly affected by its endogenous content and transport rate. The shoot apex is a major source of endogenous auxin, which is mainly transported by both influx (AUX1) and efflux (PIN) carriers in a specific basipetal active transport through the vascular parenchyma in stems. As part of a larger study to investigate the causes of low rooting in E. globulus microcuttings without exogenous auxin, we evaluated the expression profiles of AUX1 andPIN1 during the process of adventitious rooting using qPCR.