Submitted to: Plant Animal and Microbe Genomes Conference
Publication Type: Abstract Only
Publication Acceptance Date: January 12, 2002
Publication Date: N/A
Technical Abstract: Essential mineral nutrients such as nitrogen, phosphorus, potassium, and iron play vital roles in plant growth, development and ultimately, in agricultural production. As part of a root genomics program using tomato as a model plant species, we previously conducted gene expression profiling studies to identify root genes whose expression is rapidly and strongly upregulated by changes in plant mineral nutrient (N, P, K, or Fe) status. From this study, we have found that novel genes encoding putative tomato transcription factor and hemoglogin genes are rapidly induced by withholding Pi, K or Fe or by NO3- resupply. It was found that neither gene was induced by other abiotic stresses such as salt or cold, and both genes were preferentially expressed in roots compared with other organs, suggesting that these genes may play specific roles in mineral nutrition. In order to begin to understand their roles in plant function, these genes have been overexpressed in Arabidopsis thaliana seedlings using Agrobacterium tumefaciens-mediated transformation. Transformants are being analyzed in relation to various mineral nutrition-related parameters, including root and shoot mineral nutrient composition, and the influence of various mineral deficiencies and toxicities on root and shoot growth. Metabolic profiling will also be performed to determine if any significant changes in plant metabolism are occurring due to transgene expression. These results will be presented and discussed in relation to the roles of these genes in plant mineral nutrition.