Sequence Variations Of The Maize ZmYS1 Gene And Their Association With Kernel Mineral Concentrations

Iron (Fe) is an important and essential micronutrient for human, and iron deficiency is the most common micronutrient deficiency worldwide. Researches on the genetic basis of iron concentration in maize kernels will provide guidance for breeding of kernel iron-rich maize inbreds. The maize Yellow Stripe 1 (ZmYS1) gene, encoding a protein of the oligopeptide transporter (OPT) family, plays important roles in taking up Fe (III)-phytosiderophore complexes into roots. Here, we re-sequenced the genomic sequences of the maize ZmYS1 gene in 88 elite inbred lines, and detected the nucleotide polymorphisms, haplotype diversity, linkage disequilibrium (LD), and association with concentrations of copper (Cu), Fe, zinc (Zn), calcium (Ca), potassium (K), manganese (Mg) and phosphorus (P) in maize kernels. A total of 71 sequence variants, including 61 SNPs and 10 indels, were detected in this gene from the tested population. Although the frequency of polymorphism in intron regions is much higher than that of coding region, the SNPs in the coding region classified this gene into 14 haplotypes, which encode 13 different ZmYSl proteins. Numerous polymorphic sites in maize ZmYSl locus were in LD that decayed with increasing physical distance, and at least 14 recombination events contributed to the LD and haplotype diversity of this gene. Based on the result of candidate gene association analysis, one nonsynonymous site in the ZmYS1 gene is significantly associated with the maize kernel Fe concentration, while two other nonsynonymous sites are associated with Zn concentration. These results suggested that the polymorphisms in maize ZmYSl locus could be used in molecular marker-assisted selection for biofortification of the kernel mineral concentrations in maize breeding programs.