Ploidy and size at multiple scales in the Arabidopsis sepal (Plant Cell)

Ploidy refers to the number of genomes contained within a nucleus. Ploidy levels can increase through whole-genome duplication, which affects every cell equally, and through endoreduplication, a cell-by-cell process in which DNA synthesis is not accompanied by cytokinesis. Robinson et al. investigated how increasing ploidy (both types) affects nuclear, cell and organ size. They found that there is a general increase in nuclear size that accompanies increasing ploidy, which is accompanied by a generally proportional increase in cell size. The use of a mutant with a small nuclear size showed that the cell size scales with DNA content, not nuclear size. Although organ size increases somewhat with increasing ploidy, the effect is not proportional to DNA content due to a tendency towards decreased cell number. (Summary by Mary Williams) Plant Cell 10.1105/tpc.18.00344