Distinctive plasticity of maize (Zea mays) root types to variable nitrate concentration

Maize roots vary their growth in response to nitrate (NO-3) concentration in the environment, but growth plasticity differs among root types. We assessed the morphological response of lateral and axial roots on the primary, seminal, and crown root types exposed to 0, 1, 2, 3.9, and 7.8 mmol L-1NO-3. Higher NO-3 concentration did not change the growth of all axial roots and laterals of primary roots but caused positive quadratic growth in laterals of the seminal and crown root types. Maize root plasticity to NO-3 concentrations is the result of differential growth of laterals on seminal and crown root types.