Table 1. Fourteen Arabidopsis traits investigated under three magnesium (Mg) treatments.

Trait Category	Trait Identifier	Full Name of Trait	Unita	Trait Description	Annotation
MT	RGT	Days to root germination	d	The number of days from seeding until emergence, with more than half of seedlings having a first radicle	Root germination and lateral root number data were shown as the value obtained in low- or high-Mg treatment minus those under normal-Mg treatment. The primary root values for the low-Mg or high-Mg treatment were then divided by values obtained from normal-Mg treatment
	PRL	Primary root length	cm	After 8 d of growth under the treatments, plants were flattened directly on agar and imaged using a camera
	LRN	Lateral root number	cm	After 8 d growth of under the treatments, plants were flattened directly on agar and imaged using a camera
	SGT	Days to shoot germination	d	Normal	Shoot germination data were shown as the value obtained in low- or high-Mg treatment minus those under normal-Mg treatment. The epicotyl length and rosette width values for low-Mg or high-Mg treatment were then divided by values obtained from normal-Mg treatment
	EL	Epicotyl length	cm	After 8 d of growth under the treatments, plants were flattened directly on agar and imaged using a camera
	RL	Rosette width length	cm	After 8 d of growth under the treatments, plants were flattened directly on agar and imaged using a camera
	Biomass	Fresh weight of plants	mg	All fully expanded and nonlesioned seedlings were collected from four plants for each accession and weighed to obtain fresh weight measurements. The results represent average values across all available replicates	Biomass and nutrient concentration data were calculated as the ratio of the treatment value (low Mg or high Mg) divided by the normal, in which seeds were germinated in normal Mg
NCT	K	Potassium concentration per plant	mg/g	Elemental analysis was performed with an ICP-MS (Agilent 7500a). All samples were normalized to calculated weights as previously described. The results represent average values across all available replicates
	Ca	Calcium concentration per plant	mg/g
	Mg	Magnesium concentration per plant	mg/g
	S	Sulfur concentration per plant	mg/g
	Fe	Iron concentration per plant	mg/g
	Mn	Manganese concentration per plant	mg/g
	Na	Sodium concentration per plant	mg/g

MT, morphological traits; NCT nutrition concentration traits; ICP-MS, inductively-coupled plasma mass spectrometry.

^aFor NCT, the units are measured for fresh weight.