Ca and Mg distribution in Brassica rapa leaves

Leafy vegetable Brassica crops are important sources of dietary calcium and magnesium, and it may be possible to increase their concentrations through breeding or agronomic practices. Rios et al. characterize the internal distribution of Ca and Mg in the leaves of a model Brassica species (B. rapa) under manipulated exogenous supply, and find that concentrations are greatest in palisade and spongy mesophyll cells for Ca and Mg, respectively. The results are consistent with Arabidopsis thaliana and other Brassicaceae, providing phenotypic evidence that conserved mechanisms regulate leaf Ca and Mg distribution at a cellular scale. The future study of Arabidopsis gene orthologues in B. rapa may thus provide a model-to-crop translation pathway for targeted breeding.