Interactive effects between salinity and nutrient deficiency on biomass production and bio-active compounds accumulation in the halophyte Crithmum maritimum

Abstract

Plant bioactive metabolites play a pivotal role in protection against environmental stresses and offer great potential for nutraceutical exploitation. In this sense, halophytes present an exceptional opportunity for sustainable saline agriculture since they can massively accumulate bioactive metabolites under stressful conditions. We investigated the responses of the halophyte Crithmum maritimum to increasing salinity, nutrient deficient and their interaction. We hypothesized that the concentration of bioactive compounds would increase together with salinity and nutrient deficient, and that the interaction between these two stresses would produce synergic effects on bioactive compounds accumulation. We studied the tolerance and foliar accumulation of nutrients and bioactive compounds (amino acids, phenols, terpenes and fatty acids) for C. maritimum in response to salinity and nutrient deprivation in greenhouse controlled conditions. The high salinity tolerance of C. maritimum was not diminished by the interaction of salinity with nutrient limitation. Mineral nutrition deficit and saturated fatty acid accumulation were induced at 200–500 mM NaCl, and accumulation of polyphenol 5-caffeoylquinic acid and some amino acids were identified as nutrient deficiency markers. C. maritimum responded mainly to increasing salinity by reducing foliar accumulation of five terpenes and total lipids, and to nutrient limitation by increasing the concentration of vaccenic acid and 5-caffeoylquinic acid. The interaction between salinity and nutrient availability provoked antagonistic and synergistic effects on the accumulation of terpenes and fatty acids. C. maritimum showed high physiological phenotypic plasticity in the response to salt stress, nutrient deficiency and their combination.