ORIGINAL PAPER A nonsense mutation in a putative sulphate transporter gene results in low phytic acid in barley Hongxia Ye & Xiao-Qi Zhang & Sue Broughton & Sharon Westcott & Dianxing Wu & Reg Lance & Chengdao Li Received: 18 November 2010 / Revised: 23 December 2010 / Accepted: 29 December 2010 / Published online: 18 January 2011 # Springer-Verlag 2011 Abstract Low phytic acid grains can provide a solution to dietary micronutrient deficiency and environmental pollution. A low phytic acid 1-1 (lpa1-1) barley mutant was identified using forward genetics and the mutant gene was mapped to chromosome 2HL. Comparative genomic analysis revealed that the lpa1-1 gene was located in the syntenic region of the rice Os-lpa-MH86-1 gene on chromosome 4. The gene ortholog of rice Os-lpa-MH86-1 (designated as HvST) was isolated from barley using polymerase chain reaction and mapped to chromosome 2HL in a doubled haploid popula- tion of Clipper×Sahara. The results demonstrate the collin- earity between the rice Os-lpa-MH86-1 gene and the barley lpa1-1 region. Sequence analysis of HvST revealed a single base pair substitution (C→T transition) in the last exon of the gene in lpa1-1 (M422), which resulted in a nonsense mutation. These results will facilitate our understanding of the molecular mechanisms controlling the low phytic acid phenotype and assist in the development of a diagnostic marker for the selection of the lpa1-1 gene in barley. Keywords Comparative mapping . Candidate gene . Rice . Barley . HvST Introduction Phytic acid (PA, myo-inositol-1,2,3,4,5,6-hexakisphos- phate) is the major storage form of phosphorus in barley and cereal grains and accounts for 65–85% of the total seed phosphorus (Raboy 1997; Raboy et al. 2001). Phytic acid has the potential to form very stable complexes with minerals and proteins which can cause problems in monogastric animals, as the animals may have an absence or insufficient amount of phytase in their digestive systems. As a result, the availability of some essential elements such as iron, zinc, calcium, potassium, and magnesium is decreased, and large amounts of phytate-P are excreted to the environment with animal waste, contributing to the eutrophication of lakes and rivers (Raboy 2001). Thus, high levels of phytic acid in feed grain can result in both nutritional and environmental problems. Over the past decades, low phytic acid (lpa) has become a desirable trait for grain crops. Mutants with low phytic acid have been isolated in several major crops as a result of chemical mutagenesis or gamma irradiation including barley (Hordeum vulgare L.) (Dorsch et al. 2003; Larson et al. 1998; Oliver et al. 2009), rice (Oryza spp.) (Kim et al. 2008a, b; Larson et al. 2000; Liu et al. 2007; Ren et al. 2007; Zhao et al. 2008a, b), wheat (Triticum spp.) (Guttieri et al. 2003), maize (Zea mays L.) (Pilu et al. 2003, Raboy et H. Ye : D. Wu (*) State Key Lab of Rice Biology and Key Lab of the Ministry of Agriculture for Nuclear–Agricultural Sciences, Zhejiang University, Hangzhou 310029, People’ s Republic of China e-mail: dxwu@zju.edu.cn H. Ye : S. Broughton : S. Westcott : R. Lance : C. Li Department of Agriculture and Food, Government of Western Australia, 3 Baron-Hay Court, South Perth, WA 6150, Australia X.-Q. Zhang : C. Li (*) The State Agricultural Biotechnology Centre, Murdoch University, Murdoch, Perth 6150, Australia e-mail: chengdao.li@agric.wa.gov.au H. Ye Huzhou Academy of Agricultural Sciences, Huzhou, Zhejiang 313000, People’ s Republic of China Funct Integr Genomics (2011) 11:103–110 DOI 10.1007/s10142-011-0209-4