Prof Phil Gilmartin
Professor Qi XIE
Plant GATA transcription first attracted interest as potential regulators of light-responsive gene expression due to the presence of conserved GATAAGG motifs upstream of many light-regulated genes. However, the Arabidopsis genome contains 29 different genes encoding GATA (type IV zinc finger) proteins. Analysis of mutants as well as reverse genetic approaches have indicated that some members of the Arabidopsis GATA family regulate metabolic gene expression as well as contribute to developmental coordination of transcription. Our expression analyses of the full GATA gene family further supports the original proposition that some gene family members encode proteins of importance in light-responsive gene expression and circadian regulation. Microarray analysis of over-expression and T-DNA insertion lines for two of the GATA genes, GATA1 and GATA3 reveal an unexpected reciprocal regulation of downstream genes. Several genes that are up-regulated in a GATA1 T-DNA insertion line are also up-regulated in a GATA3 over-expression line. These observations lead us to predict that GATA1 and GATA3 are reciprocal regulators of gene expression. A number of the genes that are up-regulated following perturbation of GATA1 and GATA3 expression are involved in salt stress responses. The joint lab project will focus on the analysis of GATA1 and GATA3 in rice with the aim of dissecting the molecular basis for mis-regulation of salt stress response genes seen in GATA1 and GATA3 mutants.