Abstract
Chenopodium quinoa (quinoa) is considered a superfood, as it has
favourable nutrient composition and is gluten free. Quinoa has high
tolerance to several abiotic stresses, i.e. salinity, water deficit
(drought) and cold. The tolerance mechanisms are yet to be elucidated.
Quinoa has Epidermal Bladder Cells (EBCs) that densely cover the shoot
surface, particularly the younger parts of the plant. Here, we report on
the EBC’s primary and secondary metabolomes, as well as the lipidome in
response to abiotic stresses. EBCs were isolated from plants after cold,
heat, high-light, water deficit and salt treatments. We used untargeted
Gas Chromatography-Mass Spectrometry (GC-MS) to analyse metabolites and
untargeted and targeted Liquid Chromatography-MS (LC-MS) for lipids and
secondary metabolite analyses. We identified 64 primary metabolites,
including sugars, organic acids and amino acids, 19 secondary
metabolites, including phenolic compounds, betanin and saponins and 240
lipids categorized in five groups including glycerolipids and
phospholipids. Although we found only few changes in the metabolic
composition of bladders in response to abiotic stresses, metabolites
related with heat, cold and high-light treatments, but not salt stress,
were changed significantly. Na+ concentrations were
low in EBCs with all treatments, and approximately two orders of
magnitude lower than K+ concentrations.