Abstract
We established transcriptome data of hormone responses in AtGenExpress project. We have also established correlation analysis to estimate hormone status from microarray data by using hormone-inducible genes as markers. In this study, we analyzed hormone series data from AtGenExpress and found that aminoethoxyvinylglycine (AVG) had the strongest anti-auxin activity in Arabidopsis. It inhibited growth, auxin accumulation, and expression of Aux/IAA genes in Arabidopsis seedlings, which recovered from inhibition of the gene expression after exogenous application of IAA and its intermediates. Since this inhibitor has characteristics to inhibit pyridoxal-phosphate (PLP)-dependent enzymes, we analyzed possible PLP-dependent steps of auxin biosynthesis in enzyme extracts from Arabidopsis and wheat. We also investigated involvement of ethylene using ethylene-insensitive mutants and ethylene-marker genes. As a result, we concluded that this is the first auxin-biosynthesis inhibitor, targeting L-Trp aminotransferase. This work was supported by the Promotion of Basic and Applied Researches for Innovations in Bio-oriented Industry (BRAIN).
