Abstract: Wood vinegar (WV) is an important plant growth regulator-like substance used in agriculture worldwide,but little known on its mechanism at molecular level restricted its wider and further application.In this study,the effects of WV and auxin on the growth of Arabidopsis thaliana were compared at both genetic and morphologic level through semi-quantitative PCR (SQ-PCR) and condition-controlled culturing.The results showed that WV can regulate auxin-inducible genes like Aux/IAA1, Aux/IAA5, Aux/IAA19, ARF19 and SAUR-AC1 expression.Through interaction between Aux/IAAs and ARFs,WV had a negative feedback in its regulation pathway,similar to the homolog of auxin IAA’s.In addition,the morphologic comparison results showed that WV and auxin IAA both repressed leaf number and its expansion but promoted main root elongation and lateral root formation.These results indicated that the regulation effect of WV was similar but not identical to that of auxin.The results presented in this study will contribute to the wider and more precise usage of WV in agriculture.

Key words: wood vinegar, IAA, regulation pathway, molecular mechanism