Root cortical anatomy and nitrogen capture

We are exploring how certain anatomical traits reduce root construction and maintenance cost. This reduction in cost improves root growth and uptake of nitrogen. For instance, in the video, we show the simulated root architecture of two genotypes with contrasting cortical cell file number (CCFN); reduced CCFN (green), and increased CCFN (red) under moderate N stress.

Reduced CCFN decreased metabolic cost, improving root growth, allowing the root system to grow deeper and capturing the nitrogen that is leaching. The continuous gradient from red to blue in the simulated soil represents nitrogen depletion by root uptake and leaching. We simulated the root systems with OpenSimRoot (OSR), a structural-functional model that simulates root growth and interaction with soil in three dimensions.

Domestication of root traits in the earliest maize

We are also exploring the effect of domestication in root traits. We used laser ablation tomography to characterize the root anatomy of 5,300-y-old maize specimens recovered from San Marcos (Tehuacán, Mexico), revealing exquisite preservation of their cellular organization.

We observed the presence of Multiseriate Cortical Sclerenchyma (MCS), a root anatomical phenotype recently discovered by Hannah Schneider et al.. MCS increases the tensile strength of the root and was associated with improved penetration of hard soils. This trait is absent in teosintes. The presence of MCS 5000 years ago suggest an early fixation during domestication, however its role during the the establishment of Mesoamerican agriculture is still unknown. We are using simulations to understand the effect of MCS in early stages of agriculture in Mesoamerica.

Local adaptation of root traits

Also, we are investigating the root adaptations of local varieties from humid (Environment A) and arid (Environment B) regions across Latinamerica. We designed root phenotypes and environments corresponding to maize landraces coming from contrasting edaphic conditions. Then we reciprocally transplanted in silico to evaluate their performance.

Simulation of phenotypes A and B at day 40 under both environments. Red in the soil represents the nitrogen concentration. The transition to blue in the root segments represents nitrogen capture.
Simulation of phenotypes A and B at day 40 under both environments. Red in the soil represents the nitrogen concentration. The transition to blue in the root segments represents nitrogen capture.

Reciprocal Transplanting In silico - Envinronment A

Reciprocal Transplanting In silico - Envinronment B

Keep tuned for our following results!