3d root model: exploring root developmental plasticity to...
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3D root model: Exploring root developmental plasticity to soil
nutrients
Sarlikioti V, Pagés L, et al.
Nutrient distribution Root plasticity
Root plasticity Nutrient uptake
3D dimenional: nutrient distribution x root plasticity
To include the plasticity mechanisms:
of root perception and orientation towards nutrient rich zones (Chemotropism)
of adaptation of the linear branching density (IBD)
of the relative growth rate modification of the lateral roots relatively to the mother root (RMDB)
To study the effect of such mechanisms on rootarchitecture and uptake at the root level for four different nutrient scenarios
Layer
Patch
Gradient
Random
Nitrogen sources (3500 sources, d= 0.005m)
Phosphorus sources (2000 sources, d= 0.002m)
Root model 3 modules
Root Meristem
Root Segment
Root Primordium
Meristem length += Actual Growth Rate
Root segment length (SRL)= constant
no Segments= meristem length/SRL
Uptake occurs at the meristem level
If the distance between nutrient source and the root
meristem >= a defined distance
Source uptake
The distance is defined according to the mobility of
each source
No nutrient movement is considered at this stage
Inter-Branching Distance (IBD)
Maximal diameter of the root branch (RMDB)
Chemotropism
The root turns towards a nutrient source if:
The source should be within a defined cone with root meristem as its apex.
The distance between the root tip and the source is equal or smaller a threshold distance.
No distribution Patch distribution
Segment Length = SRL –α*Local_uptake
Local_uptake= average uptake of the last three days
SRL, α are constants
Local_uptake
Segment length
SRL
Patch distribution Random gradient distribution
Primodium diameter =
MRD *(α+β*local uptake)*exp(VAR*R)
Local_uptake= average uptake of the last three days
MRD, α, β are constants
Local_uptake
Primordium Diameter
MRD
Mother Diameter
Daughter Diameter
MRD
Patch distribution Random gradient distribution
Root uptake
Significant effect of nutrient distribution on root
plasticity and architecture
Nutrient uptake higher for gradient and layer
distributions
Most efficient plasticity scenarios
MRDBIBDChemotropism