Genotypic variation in the sulfur assimilation and metabolism of onion (Allium cepa L.) I. Plant composition and transcript accumulation

► Onion exhibits significant genotypic differences to S-deprivation. ► We compared S-metabolism in a mild and a pungent genotype. ► The pungent genotype displays significantly higher cysteine content. ► The genotypes differed significantly in root ATP sulfurylase and HAST transcript accumulation.