UC Riverside

Aluminum (Al) toxicity is a global problem that leads to stoppage of root growth, overall smaller plant size and lower crop yields. Previous research has shown the molecular response of plants to Al toxicity occurs through a DNA damage response pathway involving ATR and SOG1 genes. To explore this phenomenon further both transcriptomic and genomic experiments were performed using Arabidopsis Thaliana. The goal of the transcriptomics was to determine a gene or suite of genes that were deferentially expressed with Al3+ exposure that could potentially confer Al tolerance to crop plants. While a companion genomics study aimed to understand what type of genomic damage was occurring following Al exposure. Arabidopsis seedlings were grown on gel soaked media plates in the absences or presence of Al3+, before nucleic acids were harvested for Illumina short read sequencing. Transcriptionally, a suite of genes that included known Al response factors and some novel genes were identified using a cut off of 2 fold change and a false discover rate of 1%, 10 of the genes had their expression validated using quantitative real time PCR. In addition, it was identified genetically that Al toxicity leads to the generation of one and two base pair insertions and deletions, which were determined to be statistically significant. With this knowledge future experiments can be performed with the promise of finding the molecular critical to responding to Al exposure and how to use this response to confer Al tolerance to crop plants. Such experiments should include testing Arabidopsis mutants that have reactive oxygen species related genes knocked out or overexpressed to evaluate the level of genomic damage in the presence Al3+. Additionally, genes identified from this transcriptional study should have their expression modified to further understand their role in Al toxicity. Pathway interaction studies with these factors could highlight the full molecular pathway of the plants response to Al exposure.