Table 4.

Description of parameters and constraints used in the models and their respective source whenever available

Name	Symbol	Constraints/range	Reference/note
SPS KM	KM5	0.1– 2	25, 52, 53 ,
			Spinacia oleracea
			Pisum sativum
Inv KM	KM6	7–13	54
			Arabidopsis thaliana Oy-0
Hxk KM for GlcK activity	KM7	1.1–0.2	55, 56
		(0.01–2 for gin2-1)	Helianthus annuus, various
Hxk KM for FrcK activity	KM8	0.1–3 (0.1–5 for gin2-1)	55, 56
			Helianthus annuus, various
Inv Ki for Frc inhibition	Ki6a	0.001–10	57
			Lolium temulentum
Inv Ki for Glc inhibition	Ki6b	0.001–10	Assumed and optimized
Hxk Ki for Frc inhibition	Ki7	0.01–10	Assumed and optimized
Hxk Ki for Glc inhibition	Ki8	0.001–10	Assumed and optimized
SPS maximal reaction rate	Vm5	10–20 for both	Measured
Inv maximal reaction rate	Vm6	60–100 for Ler	Measured
		70–120 for gin2-1
GlcK maximal reaction rate	Vm7	2–4 for Ler	Measured
		0–1 for gin2-1
FrcK maximal reaction rate	Vm8	5–10 for Ler	Measured
		2–5 for gin2-1
Photosynthesis rate	r1		Measured and splined
respiration rate	r2	−28.6 for Ler N	Measured
		−37.5 for gin2-1 N
		−44.0 for Ler HL
		−47.5 for gin2-1 HL
Rate of starch synthesis	r3	1–7.5 for N	Measured and splined
		5–26 for HL
Rate of starch degradation	r4	−4 to −10 for N	Measured and splined
		−6 to −20 for HL
SPS activity as MM	r5	(Vm5∙HP)/(km5 + HP)	Measured and splined
Inv activity as MM	r6	(Vm6∙Suc)/((km6∙(1 + Frc/Ki6a) + Suc)∙(1 + Glc/Ki6b))	Measured and splined24,47,49
GlcK activity as MM	r7	(Vm7 ∙Glc)/(km7 ∙(1 + Frc/Ki7) + Glc)	Measured and splined49
FrcK activity as MM	r8	(Vm8 ∙Frc)/(km8∙ (1 + Glc/Ki8) + Frc)	Measured and splined49
Aa synthesis from Cit as MBE	r9	r_ca ∙Cit	Assumed and optimized
		r_ca ∈ {0.01,100}
SC formation from Aa as MBE	r10	a_ba∙Aa	Assumed and optimized
		a_ba ∈ {0,1}
SC formation from HP as MBE	r11	ab_hp∙HP	Assumed and optimized
		ab_hp ∈ {0.0001,100}
Exp rate from Aa as MBE	r12	aa_e∙Aa	Assumed and optimized
		aa_e ∈ {0.0001,10}
Exp rate from Suc as MBE	r13	a_e∙Suc	Assumed and optimized
		a_e ∈ {0.0001,10}
Cit formation from HP as MBE	r14	hp_c∙HP	Assumed and optimized
		hp_c ∈ {0.01,10}
MF formation from HP as MBE	r15	hp_mf∙HP	Assumed and optimized
		hp_mf ∈ {0.01,10}
MF formation from Cit as MBE	r16	cit_mf∙Cit	Assumed and optimized
		cit_mf ∈ {0.01,10}
Cit formation from MF as MBE	r17	mf_cit∙MF	Assumed and optimized
		mf_cit ∈ {0.01,10}

SPS sucrose-phosphate-synthase, Inv invertase, Hxk hexokinase, GlcK glucokinase, FrcK fructokinase, Frc fructose, Glc glucose, HP hexose phosphate, Exp export, SC structural carbon, Suc sucrose, Cit citrate, MF malate/fumarate, Aa amino acids, MM Michaelis–Menten kinetic, MBE mass balance equation. K_M are given in mM and V_m in µmol h⁻¹ gFW⁻¹