ARS | Publication request: Transcriptional regulation in maize roots under aluminum stress

Submitted to: Plant and Animal Genome Conference
Publication Type: Abstract Only
Publication Acceptance Date: January 8, 2008
Publication Date: January 16, 2008
Citation: Maron, L., Kirst, M., Mao, C., Menossi, M., Kochian, L.V. 2008. Transcriptional regulation in maize roots under aluminum stress. Plant and Animal Genome Conference.

Technical Abstract: Aluminum toxicity in acid soils is a major factor limiting crop yields. The importance of this topic is underscored by the intensive research focused on the mechanisms underlying plant Al tolerance. A major tolerance mechanism identified in several plant species is the exclusion of Al from the root via Al-activated organic acid release. In species such as wheat, tolerance seems to be based solely on this mechanism. In contrast, Al tolerance in maize is a complex phenomenon, involving multiple genes and physiological mechanisms. To begin to elucidate the molecular basis of Al toxicity/tolerance in maize, we performed a detailed temporal and comparative analysis of the physiology and transcriptional regulation in maize roots under Al stress. Firstly, we investigated physiological parameters relevant to Al tolerance using a time-course approach in two tropical genotypes contrasting for Al tolerance. In addition, microarrays were applied to investigate changes in gene expression in the roots of these two maize varieties under the same conditions. Our results demonstrate that Al strongly influences root transcriptional regulation. Al affected the expression of a significantly larger number of genes in the Al-sensitive genotype, presumably due to more severe Al toxicity. Nevertheless, a number of genes exhibited higher expression in the tolerant genotype in response to Al. Differentially regulated genes related to cell processes affected by Al toxicity are also discussed. The present work significantly expands our understanding of gene expression regulation of under Al stress and will be important in guiding future research in maize Al tolerance.