“…Moreover, in the aspen P. tremula , in order to increase the endogenous auxin content, the UGT gene from corn, encoding a UDPG-transferase that catalyzes the conjugation of IAA with glucose for easier transport, was introduced. A correlation between the enzyme activity, the content of free IAA and root formation was found in this transgenic line, thus confirming the promoting role of auxin in AR formation in this difficult-to-root aspen ( Salyaev et al, 2006 ). Several auxin biosynthetic and signaling pathway genes, including transcription factors, have been identified in arabidopsis and other species and have been shown to influence AR formation (reviewed in Bellini et al, 2014 ; Pacurar et al, 2014 ; Lakehal and Bellini, 2019 ).…”