Effect of Salinity and Nitrogen Sources on the Leaf Quality, Biomass, and Metabolic Responses of Two Ecotypes of <i>Portulaca oleracea</i>
2020
Maria Camalle | Dominic Standing | Mohammed Jitan | Rana Muhaisen | Nidal Bader | Majed Bsoul | Yvonne Ventura | Aigerim Soltabayeva | Moshe Sagi
Halophytic plants are, by definition, well adapted to saline soils. However, even halophytes can face nutritional imbalance and the accumulation of high levels of compounds such as oxalic acid (OA), and nitrate (NO<sub>3</sub><sup>−</sup>). These compounds compromise the potential nutritional health benefits associated with salt-tolerant plants such as <i>Portulaca oleracea</i> or Purslane. Purslane has long been known to be a highly nutritious leafy vegetable particularly with respect to high levels of omega-3 fatty acids. Thus, preventing the accumulation of non-nutritional compounds will allow plants to be grown in saline conditions as crops. Two ecotypes (ET and RN) of <i>Portulaca oleracea</i> plants were grown under growth room conditions with two levels of salinity (0, 50 mM NaCl) and three ratios of nitrate: ammonium (0:100%; 33:66%; 25:75% NO<sub>3</sub><sup>−</sup>:NH<sub>4</sub><sup>+</sup>). The results show that both ecotypes, when exposed to elevated NO<sub>3</sub><sup>−</sup>, showed severe leaf chlorosis, high levels of OA, citric acid, and malic acid. Compared to ecotype RN, ecotype ET, exposed to elevated NH<sub>4</sub><sup>+</sup> concentrations (33% and 75%) and 50 mM NaCl, displayed a marked reduction in OA content, increased total chlorophyll and carotenoid contents, crude protein content, total fatty acid (TFA) and α-Linolenic acid (ALA), enhancing leaf quality. This opens the potential to grow high biomass, low OA <i>P. oleracae</i> crops. Lastly, our experiments suggest that ecotype ET copes with saline conditions and elevated NH<sub>4</sub><sup>+</sup> through shifts in leaf metabolites.
显示更多 [+] 显示较少 [-]