Abstract

Chenopodium quinoa Willd. is an edible crop plant adapted to the climatic conditions of the South American Andes, where it thrives under extreme environmental conditions such as saline soils, drought, high UV radiation and broad temperature fluctuations. The prolonged exposure of this crop to high salinity and low relative humidity has promoted the development of efficient mechanisms to retain water within the intracellular compartments and avoid desiccation, including accumulation of osmoprotectants. In this study, the effect of osmotic stress (250 mM KCl) was evaluated on osmolyte accumulation at different phenological stages of quinoa growth (branched, panicle, flowering) compared to control (0 mM KCl). The osmotic stimulus increased the concentrations of proline, glycine betaine, sucrose, fructose, glucose, and trehalose two- to seven-fold compared to a low salinity conditions. This is the first report to show significant increase in trehalose in response to osmotic disturbance at three different phenological stages of quinoa growth, opening a new avenue to explore the protective role of trehalose against osmotic-induced damage in this crop.

Key words: Compatible solutes, osmotic stress, quinoa, phenology.