Nutritional evaluation of seashore mallow seed, Kosteletzkya virginica

Overexpression of KvCHX Enhances Salt Tolerance in Arabidopsis thaliana Seedlings

The CHX (cation/H+ exchanger) family plays an important role in the transmembrane transport of cation/H+ in plants. The aim of this study was to identify and functionally analyze the KvCHX gene in the halophyte Kosteletzkya virginica to investigate its role in regulating the K+/Na+ ratio under salinity tolerance. Based on a partial gene sequence of EST from K. virginica, the full-length DNA sequence of the KvCHX gene was obtained using genome walking technology. Structural analysis and phylogenetic relationship analysis showed that the KvCHX gene was closely related to the AtCHX17 gene. The KvCHX overexpression vector was successfully constructed and transformed into Arabidopsis via floral dipping. Arabidopsis seedlings overexpressing KvCHX showed an enhanced tolerance to salt stress compared with wild-type plants. Transgenic Arabidopsis seedlings grew better under K+ deficiency than WT. The results showed that KvCHX could promote the uptake of K+, increase the ratio of K+/Na+, and promote the growth of plants under K+ deficiency and treatment with NaCl solution. KvCHX is involved in K+ transport and improves plant salt tolerance by coordinating K+ acquisition and homeostasis.

Evaluation of Salicornia bigelovii Germplasm for Food Use in Egypt and the United Arab Emirates Based on Agronomic Traits and Nutritional Composition

Climate change significantly aggravates the quality of soil and water, especially in desert regions such as the United Arab Emirates (UAE) and Egypt concluding in an alarming increase in salinity in the reservoirs of the natural resources. Saline farming rises as a promising solution, utilizing low-quality water and land resources to grow salt-tolerant varieties of conventional crops and halophytes. Samphire (Salicornia spp.) is among the most popular multi-purpose halophytes that are locally consumed in several countries around the world as a vegetable. Six Salicornia bigelovii genotypes (ICBA-2, ICBA-3, ICBA-4, ICBA-8, ICBA-9, ICBA-10) were evaluated for their agronomic performance and nutritional composition in Dubai in UAE and, for the first time, at the Red Sea Governorate in Egypt in the 2019-2020 season using saline groundwater for irrigation (EC_w = 26 and 6.6 dS/m, respectively). ICBA-10 performed well in both locations with high green biomass and seed yield (10.9 kgm^-2 and 116.3 gm^-2, respectively, in UAE; 7.7 kgm^-2 and 82.9 gm^-2, respectively, in Egypt). ICBA-10 was, overall, also good in ion accumulation, total amino acids and unsaturated fatty acids content in both locations for shoots and seeds. Our results indicated that a lack of a drainage system and leaching fraction, the silt loam texture and the drip irrigation system might have contributed in the gradual accumulation of salts in the soil at Mubarak Valley at the end of the experiment at a higher level than ICBA. Apart from the agronomic parameters, higher salinity levels also affected ion accumulation, the amino acids and the fatty acids content for both shoots and seeds, whereas the proximate composition was affected to a lesser extent. Our findings on the high unsaturated fatty acids content under higher salinity corroborate the nutritional value of S. bigelovii oil. Due to its euhalophyte nature, S. bigelovii is a valuable source of minerals, amino acids and antioxidants that render it the most promising salt-loving plant for food use.

Root system architecture of Kosteletzkya pentacarpos (Malvaceae) and belowground environmental influences on root and aerial growth dynamics

PREMISE OF THE STUDY

Root growth and architecture of Kosteletzkya pentacarpos and its response to nutrients and soil texture were studied to facilitate domestication of this plant as a biofuel crop (seeds for oil, stems for ethanol). Because it is salt tolerant, it does not compete with food crops for land.

METHODS

Four soil treatments in the bottom chambers of two-chambered growing units (three nutrient levels in sandy loam and saline, dredged material) were used to test substrate influences on root structure and aerial growth in a greenhouse study. Simultaneously, underground reserves were determined by collecting aerial biomass of dark-grown plants. Root cores (15 × 50 cm) were taken to determine root architecture of 2-year-old field-grown plants.

KEY RESULTS

High nutrient availability increased the coarse root biomass (≥2 mm diameter) and increased capsule production. Plants grown in dredged sediment had no substantial growth differences from the controls. Underground reserves were significant. Field cores demonstrated that roots extended more than 50 cm with most of the coarse roots in the upper 20 cm and the coarse to fine root ratio decreasing with depth. Fine root surface area, measured using image-analysis software, was substantially greater than many other crops, as was root mass density.

CONCLUSIONS

Root architecture of K. pentacarpos and its responses to various nutrient levels and soil types demonstrate that it is a promising species for further development as a crop on coastal saline land including dredged material sites. Its perennial taproot system stores carbon and will perform buffer functions between upland and wetlands as sea level rises.

Mucilage and polysaccharides in the halophyte plant species Kosteletzkya virginica: localization and composition in relation to salt stress

Mucilage is thought to play a role in salinity tolerance in certain halophytic species by regulating water ascent and ion transport. The localization and composition of mucilage in the halophyte Kosteletzkya virginica was therefore investigated. Plants were grown in a hydroponic system in the presence or absence of 100mM NaCl and regularly harvested for growth parameter assessment and mucilage analysis with the gas liquid chromatography method. NaCl treatment stimulated shoot growth and biomass accumulation, had little effect on shoot and root water content, and reduced leaf water potential (Psi(w)), osmotic potential (Psi(s)) as well as stomatal conductance (g(s)). Mucilage increased in shoot, stems and roots in response to salt stress. Furthermore, changes were also observed in neutral monosaccharide components. Levels of rhamnose and uronic acid increased with salinity. Staining with a 0.5% alcian blue solution revealed the presence of mucopolyssacharides in xylem vessels and salt-induced mucilaginous precipitates on the leaf abaxial surface. Determination of ion concentrations showed that a significant increase of Na(+) and a decrease of K(+) and Ca(2+) simultaneously occurred in tissues and in mucilage under salt stress. Considering the high proportion of rhamnose and uronic acid in stem mucilage, we suggest that the pectic polysaccharide could be involved in Na(+) fixation, though only a minor fraction of accumulated sodium appeared to be firmly bound to mucilage.