Abstract
We have established hormone-series transcriptome data in AtGenExpress project. We have also established correlation analysis to estimate hormone status from microarray data using hormone-inducible genes as markers. Here, we conducted analysis of 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 all possible PLP-dependent steps of auxin biosynthesis in enzyme extracts from Arabidopsis and wheat. As a result, we found that AVG inhibits L-Trp aminotransferase, and concluded that this is the first auxin-biosynthesis inhibitor that functions both in monocot and dicots.
