Abstract

The inherent genetic diversity of maize provides a powerful material for allele mining associated with traits of interest (Buckler et al., Curr Op Plant Biol 9, 172, 2006). Screening the 26 founder lines of the maize Nested Associated Mapping (NAM) population identified candidate lines with significant variation in arbuscular mycorrhizal (AM) responsiveness and additionally lines with contrasting tolerance to low Pi-fertilization. Variation in either Pi uptake efficiency (PAE) or the internal Pi use efficiency (PUE) may correlate with either phenotypic variation. The uptake of Pi across the plasma membrane is typically mediated by Pi transporter proteins belonging to the PHT1 class. Variation in functionality or expression levels of PHT1 genes therefore might underpin variation in PAE and/or PUE . Here, we determined the sequence variation of PHT1 genes across the maize diversity panel. Focusing on the subset of candidate lines the transcriptional response of selected PHT1 genes to different phosphate regimes and/or AM colonization was examined. The molecular data were correlated with shoot biomass production and symbiotic phosphate uptake.