Characterization and Transposon Mutagenesis of the Maize (Zea mays)Pho1Gene Family - Submission to PLOS Journals

AbstractPhosphorus is an essential nutrient for all plants, but also one of the least mobile, and consequently least available, in the soil. Plants have evolved a series of molecular, metabolic and developmental adaptations to increase the acquisition of phosphorus and to maximize the efficiency of use within the plant. In Arabidopsis (Arabidopsis thaliana), the AtPHO1 protein regulates and facilitates the distribution of phosphorus within the plant. To investigate the role of PHO1 in maize (Zea mays), the B73 reference genome was searched for homologous sequences and four genes identified that were designatedZmPho1;1, ZmPho1;2a, ZmPho1;2bandZmPho1;3. ZmPho1;2aandZmPho1;2bare the most similar to AtPho1, and represent candidate co-orthologs that we hypothesize to have been retained following whole genome duplication. Tissue-and phosphate-specific differences in the accumulation ofZmPho1;2aandZmPho1;2btranscripts were observed, indicating regulatory divergence. Furthermore, evidence was obtained for the phosphate-regulated production of anti-sense transcripts associated with bothZmPho1;2aandZmPho1;2b, suggesting the possibility of regulatory crosstalk between paralogs. To characterize functional divergence betweenZmPho1;2aandZmPho1;2b, a program of transposon mutagenesis was initiated using the Ac/Ds system, and, here, we report the generation of novel alleles ofZmPho1;2aandZmPho1;2b.