Submitted to: Journal of Biological Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/11/2005
Publication Date: 6/10/2005
Citation: Baerson, S.R., Sanchez-Moreiras, A., Pedrol-Bonjoch, N., Schulz, M., Kagan, I., Agarwal, A.K., Reigosa, M.J., Duke, S.O. 2005. Detoxification and transcriptome response in arabidopsis seedlings exposed to the allelochemical benzoxazolin-2(3h)-one (boa). Journal of Biological Chemistry. 280(23): 21867-21881. Interpretive Summary: Recent technological advancements in the field of molecular biology have created powerful new approaches for the study of allelochemical interactions. One such technology is called a 'DNA microarray', which enables one to simultaneously monitor the activity of tens of thousands of genes in a single experiment. Gene expression changes that occur in response to allelochemical treatments provide important clues about how they effect plants. All organisms possess the ability to change gene expression levels when needed to counteract the effects of toxic chemicals. This response can be detected in DNA microarray experiments and may provide new insights into the types of enzymes needed to detoxify chemicals. In this manuscript, gene expression changes in response to the allelochemical BOA were described. The effects of BOA were tested for growth inhibition, then microarray experiments were performed to identify gene expression changes that occurred in response to this chemical. The manuscript reveals all of the gene expression changes that occur in response to this chemical in the plant Arabidopsis thaliana. These results will benefit researchers working in the area of allelochemical interactions and chemical detoxification pathways, and hopefully will help accelerate these efforts. The gene expression changes observed contribute to a body of knowledge that will enable researchers to pursue the study of new metabolic pathways. In addition, these results provide new information as to how certain agrichemicals effect plant gene expression. This type of understanding also enables one to predict ways that plants can become resistant to specific toxic chemicals.
Technical Abstract: Benzoxazolin-2(3H)-one (BOA), is an allelochemical most commonly associated with monocot species, formed by a two step degradation process of the hydroxamic acid glucoside of DIBOA (2,4-dihydroxy-2H-1,4-benzoxazin-3(4H)-one. Transcriptional profiling experiments were performed with ten-day-old Arabidopsis seedlings exposed to two different BOA concentrations (540 uM and 0.128 uM), representing I50 and I80 concentrations based on root growth inhibition assays. One hundred seventy eight genes were induced, and 73 were repressed in both the I50 and I80 treatments, as indicated by a modified t-test performed on log2-transformed data sets. The largest functional category of BOA-responsive genes represented protein families known to participate in pathways for chemical detoxification, cell rescue, and defense. Several novel plant protein families were identified with potential roles in xenobiotic detoxification pathways, as well as novel transcriptional responses to xenobiotics, including 2,4,-D and two different herbicide safeners. The data significantly expand upon previous studies examining plant transcriptional responses to environmental toxins, and potentially provide novel insights into xenobiotic detoxification mechanisms in plants.