What makes turnips: anatomy, physiology and transcriptome during early stages of its hypocotyl-tuber development

Abstract

Turnips: “Neeps” show early differences from non-tuber–forming relative Turnips show physiological and molecular signs of hypocotyl-tuber development as early as 16 days after sowing, a finding that could help farmers improve the performance of this important food and feed crop. A team led by Guusje Bonnema from Wageningen University and Research in the Netherlands compared the early anatomy of turnips and another closely related subspecies of Brassica rapa, the non-tuber–forming pak choi. They documented differences in the cellular organization of the xylem by day-16 after seed planting. Gene expression profiling between 1–6 weeks after sowing revealed many genes involved in hypocotyl-tuber initiation and growth. These genes affect a range of biological processes, from carbohydrate transport and metabolism to cell-wall growth to hormone regulation. Tissue culture experiments also showed that auxin, a plant growth hormone, promoted early hypocotyl-tuber development.