Figure 4.

IAA Metabolite Profiling after Sugar Induction.

(A) Proposed TRP-dependent IAA biosynthesis and IAA degradation/conjugation pathways in Arabidopsis based on Östin et al. (1998), Normanly (2010), Won et al. (2011), Novák et al. (2012), and Mano and Nemoto (2012).

(B) Analysis of known IAA metabolites indicates that a 20-h treatment with 5% Glc significantly upregulates the level of IAA, several putative IAA precursors (ANT, IAOx, IAM, IAN, and IAAld), as well as three major IAA catabolites and conjugates (oxIAA, IAAsp, and IAGlu), while the levels of TRP and TRA are significantly downregulated. Error bars indicate sd (n = 5). FW, fresh weight.

IAA metabolites quantified (in bold in [A]): tryptamine (TRA), IAOx, IAM, indole-3-pyruvic acid (IPyA), IAN, IAAld, IAAsp, IAGlu, and oxIAA. IAEt, indole-3-ethanol; IBA, indole-3-butyric acid; IG, indoleglucosinolate.