Dry bean, Phaseolus vulgaris, is an important legume for human consumption. Common bean is produced on almost 20 million hectares of land worldwide, with the highest production and consumption occurring in Latin America, Africa and US. It is well-recognized for its nutritional qualities such as high levels of protein, fiber, zinc and iron. Micronutrients are essential elements for human well-being and adequate supply of zinc will help to prevent or alleviate human zinc deficiency. The main objective of this study was to identify and characterize genes responsible for zinc transport to the seed of P. vulgaris. The first study, transcriptome analysis identified members of mineral transporter gene families expressed during bean pod development as potential candidate genes for seed mineral biofortification. Based on transcriptome analysis and proximity to QTL associated with zinc accumulation from previous studies, expression analysis of seven transporter genes of ZIP (ZRT, IRT like protein) family and three transcription factors of the bZIP family showed a diverse expression profile. High expression was found in leaves with some members being expressed in pods under low Zn fertilization. Genes potentially related to zinc transport were identifed within consensus QTL regions on chromosomes 2, 6 and 11. Genes including PvZIP, Pv bZIP, PvHMA, and PvVIT were found to be aligned to a zinc QTL both in the reference map and the consensus QTL. These results provide a useful resource for more detailed and analysis of candidate genes associated with zinc seed accumulation to develop efficient marker-assisted breeding strategies.
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