Puccinellia maritima, Spartina maritime, and Spartina patens Halophytic Grasses: Characterization of Polyphenolic and Chlorophyll Profiles and Evaluation of Their Biological Activities

Halophytic grasses have been recently targeted as possible sources of nutraceutical and medicinal compounds. Nonetheless, few studies have been conducted on the phytochemistry and biological activities of metabolites produced by these plants. Among these, Spartina maritima (Curtis) Fernald, Spartina patens (Aiton.) Muhl., and Puccinellia maritima (Hudson) Parl. are three halophytic grasses whose chemical composition and bioactivities are unknown. The present work broadens the knowledge on the polyphenolic and chlorophyll composition of these species identifying for the first time hydroxycinnamic acids and their derivatives, flavones, flavonols, lignans, as well as chlorophylls and xantophylls. The extracts were particularly rich in caffeic and ferulic acids as well as in trihydroxymethoxyflavone, apigenin and tricin derivatives. Interestingly, several of the identified compounds are relevant from a medicinal and nutraceutical point of view putting in evidence the potential of these species. Thus, the antioxidant, anti-acetylcholinesterase, antibacterial, and antifungal activities of the polyphenolic extracts were assessed as well as the photophysical properties of the chlorophyll-rich extracts. The results, herein presented for the first time, reinforce the nutritional and the medicinal potential of these halophytic grasses.

Halophytic Grasses, a New Source of Nutraceuticals? A Review on Their Secondary Metabolites and Biological Activities

The Poaceae family, known as grasses, is distributed worldwide and is considered the most important group of monocotyledonous crops. Salt stress is multifactorial, therefore to survive, halophytes evolved a variety of adaptations, which include the biosynthesis of different primary and secondary metabolites. This trait enhances the accumulation of important families of compounds crucial to the prevention of a variety of chronic diseases. Besides, if proven edible, these species could cope with the increased soil salinity responsible for the decline of arable land due to their high nutritional/nutraceutical value. Herein, the phytochemical investigations performed in halophytes from the Poaceae family as well as their biological properties were explored. Among the 65 genera and 148 species of known halophytic grasses, only 14% of the taxa were studied phytochemically and 10% were subjected to biological evaluation. Notably, in the studied species, a variety of compound families, as well as bioactivities, were demonstrated, highlighting the potential of halophytic grasses.

Physiology of salinity tolerance in Bromus danthoniae genotypes originated from saline and non-saline areas of West Iran

Genetic resources of halophytic grass species are vital factors to be explored for improvement in pasture and rangeland productivity and to elucidate mechanisms of salinity tolerance. The objective of the present study was to understand the adaptive strategies of Bromus danthoniae to a hyper-saline environment by using 80 genotypes originated from saline and non-saline areas in West Iran. Salinity treatments of 0 and 350 mm NaCl were applied for 4 weeks, and plant growth, leaf water status, ionic status, oxidative stress and salt-excretion responses were evaluated. Analysis of variance showed significant genotypic (G) variation for all traits as well as significant salinity stress (S) and G × S effects for most of the traits. Dry matter was positively correlated with K+/Na+ (r = 0.69) and Ca2+/Na+ (r = 0.66) ratios, and negatively correlated with Na+ concentration (r = –0.72). In addition, a coincidence of low concentrations of Na+ in the leaf tissues and the excretion of salt crystals on the sheath leaves and leaf blades was observed in the hyper-salinity tolerant genotypes. These observations open up new avenues for elucidating potential strategies and pathways used by halophytic grasses to avert the excess Na+ in their plant tissues.

Sustainable use of salt-degraded and abandoned farms for forage production using halophytic grasses

Four halophytic perennial forage grass species, Distichlis spicata, Paspalum vaginatum, Sporobolus virginicus and S. arabicus, were planted in three salt-degraded and abandoned farms at Mezaira’a, Madinat Zayed and Ghayathi in the United Arab Emirates. The salinity of the irrigation water in the three farms at the time of establishment of the grasses ranged between 14.1 and 17.4 dS m–1. The productivity of the grasses was assessed over 3 years (2012–14) by harvesting three times per year. Averaged over locations and species, dry biomass yields of the four grasses ranged between 32.64 and 40.68 t ha–1 year–1. Sporobolus virginicus produced highest biomass yields, followed by D. spicata, P. vaginatum and S. arabicus, although differences among the four grasses were marginal. In Madinat Zayed and Ghayathi, the average respective forage yields in terms of water productivity were estimated to be 1.68 and 2.42 kg dry matter m–3 water, better than the reported yield of the traditionally cultivated Rhodes grass (Chloris gayana) from less saline conditions. The study showed that the four halophytic grasses have the potential to contribute to rationalised use of scarce water resources for forage production, besides providing options for enhancing domestic forage production through rehabilitating the salt-affected farms that are unproductive for conventional crops.