Extended Data Fig. 10: Root tissue structure and computational model of the root, NTL8 protein stability, and map-based cloning of ntl8-D and ntl14-D mutations.

a, Diagram of root structure showing the division zone, elongation zone and differentiation zone, as well as the different tissue types in the meristematic region. Modified from ref. ⁴⁰. b, Analytical solution of the ODE model (solid line) and the computational simulation (dashed line) of the growth dilution model give the same predicted NTL8 concentration pattern. A small difference is seen in the cold because, in the simulation, division is occurring in a single step every week, as opposed to the smooth, averaged growth of the ODE model. c, NTL8 protein is stable over timescales of weeks. 4-week cold (5 °C) root imaged after a further 2 days in the warm (20 °C; 4WT2; i and ii), or 24 days in the cold (5 °C) following the 2-day warm treatment (iii and iv). i and iii show the root tip, and ii and iv show the region of the root where NTL8 accumulated during the 4-week cold period. NTL8 is maintained at those high levels after transfer to warm (ii), due to limited further growth in that region, and persists there after transfer back to the cold for at least 24 days (iv). Root structures and dying cells are shown with propidium iodide staining. Scale bars, 100 μm. Two roots were imaged. d, Diagram of map-based cloning for ntl8-D1 and ntl8-D2. Recombination numbers are indicated separately for ntl8-D1 and ntl8-D2 mutants. The diagram was drawn according to ref. ⁴¹. e, Diagram of map-based cloning for ntl14-D. Recombination numbers are indicated as shown. The diagram was drawn according to ref. ⁴².