Ribosomal DNA variation and population differentiation in Salicornia L

Salicornia bigelovii, S. brachiata and S. herbacea: Their Nutritional Characteristics and an Evaluation of Their Potential as Salt Substitutes

Excessive sodium (salt) intake in our diet is a main contributor to hypertension and a major risk factor for cardiovascular illnesses. As a result, research has made great efforts to develop salt alternatives, and Salicornia spp. offers a very high potential in the food industry for its promising functional characteristics. This review focuses on the nutritional profile, health effects and commercial potential of three specific species of the Salicornia genus: S. bigelovii, S. brachiata and S. herbacea. It also addresses the methods that are used to produce them as salt substitutes. Owing to the antinutritional and anti-inflammatory effects of its bioactive compounds, Salicornia spp. can serve as an organic biological preservative in foods with better consumer appeal when compared with chemical preservatives that are common in the food industry. Overall, the commercial use of these underutilized species will help to improve food security.

Establishment of a gene function analysis system for the euhalophyte Salicornia europaea L

A Salicornia europaea L. in vitro cell transformation system was developed and further applied to SeNHX1 function investigation. The exploration of salt-tolerant genes from halophyte has seriously been limited by the lack of self-dependent transformation system. Here, an Agrobacterium tumefaciens-mediated in vitro cell transformation system of euhalophyte Salicornia europaea L. was developed. Calli derived from hypocotyl of S. europaea were co-cultured for 3 days with Agrobacterium at OD₆₀₀ ranging from 1.0 to 1.5 and then selected with 25 mg/L hygromycin (Hyg). The transformed cells were identified from Hyg positive calli by GUS assay and qRT-PCR, and the transformation efficiency was up to 74.4%. The practicality of this system was further tested via genetic manipulation of S. europaea Na⁺/H⁺ antiporter 1 (SeNHX1) gene by creating the overexpressing, silencing, and empty vector cells. Survival ratio and Na⁺ distribution under salt treatment showed obvious differences in SeNHX1-overexpressing, -silencing, and empty vector cells, indicating the feasibility of this system to analyze gene function. This investigation is enlightening for studies in other non-model plants lacking of self-dependent transformation system.

Expressed sequence tag-simple sequence repeat-based molecular variance in two Salicornia (Amaranthaceae) populations

Salicornia spp is one of the most salt-tolerant vascular plants and is native to salt marshes and estuaries. We developed expressed sequence tag derived-simple sequence repeat (EST-SSR) markers for estimating genetic diversity and marker-assisted Salicornia breeding. Six polymorphic EST-SSRs of 40 detected 27 alleles, ranging from three to five alleles per locus. The average number of alleles per locus was 4.33 and 4.17, and the major allele frequency at locus DY529765 was high, being 0.859 and 0.857 in S. bigelovii and S. europea, respectively. Gene diversity, heterozygosity and polymorphism information content were highest at locus DY529950 and similar in these two species. Gene diversity increased with increase in the number of alleles that had a low major allele frequency at a locus. Six polymorphic loci effectively discriminated 46 taxa into three clusters via different analyses. Significant deviation of F(ST) from zero in three suggested populations for six loci indicated population differentiation and limited gene flow among them. A reduced median network established that taxon SB65 is primitive. SMART (simple modular architecture research tool) analysis of peptide sequences of six EST-SSRs showed that loci DY529765, DY529950 and EC906203 contained transmembrane, TLC, AgrB and NTR domains and might be involved in salinity stress tolerance. These EST-SSRs are a valuable resource for marker development and may be useful in marker-assisted Salicornia breeding.