Quantitative trait loci mapping of metal concentrations in leaves of the maize IBM population

Abstract

Characterizing concentrations of several beneficiary and toxic metals in maize leaves is of importance for ionomic studies and for silage production. The intermated B73 × Mo17 maize population (IBM) was evaluated for concentrations of eight metals (cadmium - Cd, copper - Cu, iron - Fe, potassium - K, magnesium - Mg, manganese - Mn, strontium - Sr and zinc - Zn) in ear-leaf to map quantitative trait loci (QTL) with 2161 molecular markers across the genome. QTL analysis revealed nine significant QTLs for concentrations of Cd, Cu, Fe, K, Mg and Sr combined over two environments. Median resolution for the QTL interval was less than 1 cM on a regular F2 map, which is a big improvement compared with the prior mapping (8 cM). The highest LOD scores of 15.52 and 15.31 were detected for K and Cd concentrations, respectively, explaining more than 20 percent of the phenotypic variance. No QTLs were found to be colocalized. QTL mapping in the IBM population did not confirm our earlier QTL results demonstrating considerable QTL ×genetic background interaction. The only exception is confirmation of the major QTL for Cd accumulation on chromosome 2. Our results could facilitate further genetic and physical mapping of genes for metal accumulation in maize.

Genetic and Physiological Characterization of a Calcium Deficiency Phenotype in Maize

“…Some heavy metals, such as Mn, Co were significantly lower in the control condition than in the treatment condition in both repetitions (Table S2). Elemental levels were largely in line with those reported in a previous study (Zdunić et al 2014).…”

Recent strategies of increasing metal tolerance and phytoremediation potential using genetic transformation of plants

“…Genetic foundations of heavy metal tolerance were extensively studied in this family and several ecotypes of hyperaccumulator species were identified (Marmiroli et al 2006 ). Recent findings in genetic mapping in maize may facilitate a production of cisgenic plants with enhanced/limited ability to accumulate cadmium in leaf tissues, which can be exploited in phytoremediation of contaminated soil (Zdunić et al 2014 ). Although, to date, there have been no reports exploiting cisgenesis and/or intragenesis in modulating plant responses to heavy metal stress, these novel techniques provide an excellent opportunity to overcome concerns with transgenesis and accelerate studies on genetic manipulations towards increased efficiency of phytoremediation.…”

Genome-Wide Association Study of Cadmium Accumulation at the Seedling Stage in Rapeseed (Brassica napus L.)

“…Differences in Cd root accumulation, root-to-shoot translocation, and transportation to organs account for variations in Cd accumulation among crops ( Ueno et al, 2009 ; Clemens et al, 2013 ). Detailed molecular genetic maps were constructed and subsequently used to identify quantitative trait locus (QTL) for Cd accumulation in Arabidopsis halleri , rice, maize, soybean, and radish ( Benitez et al, 2012 ; Xu et al, 2012 ; Abe et al, 2013 ; Zdunić et al, 2014 ; Meyer et al, 2016 ). Furthermore, genome-wide association studies (GWAS) have also been performed in Arabidopsis thaliana and barley for Cd accumulation ( Chao et al, 2012 ; Wu D. et al, 2015 ).…”