Response to "Plant-based diets and postprandial hyperkalemia"

Diet therapy for hyperkalemia in people with chronic kidney disease (CKD) has shifted considerably in recent years with the observations that reported potassium intake is weakly, or not at all, associated with plasma potassium levels in this population. One of the lingering debates is whether dietary potassium presents a risk of hyperkalemia in the postprandial state. Although there is general agreement about the need for additional research, the commentary by Varshney et al contends that the available research sufficiently demonstrates that high-potassium plant foods do not pose a risk of postprandial hyperkalemia. Others argue that this remains unsettled science. Although the traditional approach of providing people with CKD lists of high-potassium foods to limit or avoid may be unnecessary, those at high risk of hyperkalemia should be encouraged to consume balanced meals and control portions, at least until some of the key research gaps in this area are resolved. This editorial critiques the analyses offered by Varshney et al and explains the rationale for a more cautious approach to care.

The final piece of the Triangle of U: Evolution of the tetraploid Brassica carinata genome

Ethiopian mustard (Brassica carinata) is an ancient crop with remarkable stress resilience and a desirable seed fatty acid profile for biofuel uses. Brassica carinata is one of six Brassica species that share three major genomes from three diploid species (AA, BB, and CC) that spontaneously hybridized in a pairwise manner to form three allotetraploid species (AABB, AACC, and BBCC). Of the genomes of these species, that of B. carinata is the least understood. Here, we report a chromosome scale 1.31-Gbp genome assembly with 156.9-fold sequencing coverage for B. carinata, completing the reference genomes comprising the classic Triangle of U, a classical theory of the evolutionary relationships among these six species. Our assembly provides insights into the hybridization event that led to the current B. carinata genome and the genomic features that gave rise to the superior agronomic traits of B. carinata. Notably, we identified an expansion of transcription factor networks and agronomically important gene families. Completion of the Triangle of U comparative genomics platform has allowed us to examine the dynamics of polyploid evolution and the role of subgenome dominance in the domestication and continuing agronomic improvement of B. carinata and other Brassica species.