Optimum growth and quality of the edible ice plant under saline conditions.

BACKGROUND: Ice plant is a halophyte, known for its antioxidant activity and for being a highly functional food. It is capable of increasing its contents of health-promoting compounds when subjected to certain stresses such as salinity. The objective of this work was to determine the plant's best growing conditions to achieve both an optimal production of bioactive metabolites and high crop yield. Mesembryanthemum crystallinum were grown under semi-controlled conditions and four saline treatments were applied at: 0, 100, 200 and 300 mmol L-1 sodium chloride (NaCl), respectively. RESULTS: The 100 mmol L-1 NaCl treatment induced a slight increase in shoot dry weight (DW) and enhanced the leaf area. At higher salinity levels, however, the shoot biomass decreased. The concentration of starch and total proteins declined as the concentration of salt increased, while the total soluble sugars (TSS) content was lower in 100 and 300 mmol L-1 NaCl treatments. Proline increased in conditions over 100 mmol L-1 NaCl. Furthermore, plants grown with 300 mmol L-1 of NaCl presented the highest values of glutathione, ascorbic acid and vitamin C. Antioxidant enzymes activity and total phenolics increased with the severity of the salinity. CONCLUSION: Ice plant accumulates high levels of health-promoting compounds when grown with 300 mmol L-1 NaCl. A high concentration of beneficial compounds, however, is detrimental to the plant's growth. Moreover, 100 mmol L-1 NaCl treatment not only improved the concentration of bioactive and antioxidant compounds but also preserved the crop yield. It could thus be interesting to promote the cultivation of this high nutritional value plant in environments of moderate salinity. © 2021 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Genotype influences sulfur metabolism in broccoli (Brassica oleracea L.) under elevated CO2 and NaCl stress.

Climatic change predicts elevated salinity in soils as well as increased carbon dioxide dioxide [CO2] in the atmosphere. The present study aims to determine the effect of combined salinity and elevated [CO2] on sulfur (S) metabolism and S-derived phytochemicals in green and purple broccoli (cv. Naxos and cv. Viola, respectively). Elevated [CO2] involved the amelioration of salt stress, especially in cv. Viola, where a lower biomass reduction by salinity was accompanied by higher sodium (Na(+)) and chloride (Cl(-)) compartmentation in the vacuole. Moreover, salinity and elevated [CO2] affected the mineral and glucosinolate contents and the activity of biosynthetic enzymes of S-derived compounds and the degradative enzyme of glucosinolate metabolism, myrosinase, as well as the related amino acids and the antioxidant glutathione (GSH). In cv. Naxos, elevated [CO2] may trigger the antioxidant response to saline stress by means of increased GSH concentration. Also, in cv. Naxos, indolic glucosinolates were more influenced by the NaCl×CO2 interaction whereas in cv. Viola the aliphatic glucosinolates were significantly increased by these conditions. Salinity and elevated [CO2] enhanced the S cellular partitioning and metabolism affecting the myrosinase-glucosinolate system.

Natural antioxidants in purple sprouting broccoli under Mediterranean climate.

UNLABELLED: Broccoli, (Brassica oleracea var. Italica), is generally recognized as a nutritive food rich in natural antioxidants, including vitamins and phenolics compounds. Phytochemical composition of 3 different purple sprouting broccoli varieties according with their production cycle: EEP (Extra Early), EP (Early), and LP (Late) were determined. The 3 cultivars tested were grown under the same conditions in an experimental field (SE Spain) where they were not previously cultivated since these cultivars are typical of cold, Northern-European areas. EP variety showed greater growth according to the photosynthetic rate and C assimilation. However, it was not possible to obtain inflorescences for variety LP. The health-promoting compounds (vitamin C, phenolic compounds, and glucosinolates) were higher in purple broccolis than in traditionally grown green broccolis and showed differences according to the variety. With respect to the use of broccoli byproducts as source of antioxidants, any variety would be suitable although the leaves of EP variety seems the richest in total phenolic acids, whereas the amount of anthocyanins was higher in LP variety, followed by EP and EEP varieties. Under our experimental conditions, the levels of glucosinolates were higher in purple broccoli than in green cultivars and also higher than other purple broccolis grown under different climate conditions. Therefore, the results reported data for production of the EEP and EP varieties in the Mediterranean climate with potential to obtain vegetables with improved nutritional quality. PRACTICAL APPLICATION: The results of this study reported data of the health-promoting nutrients and natural antioxidants of EEP, EP, and LP purple sprouting broccoli varieties grown under the Mediterranean climate. The vitamin C, phenolic compounds, and glucosinolates in these purple varieties were higher than in traditionally grown green broccolis and other purple broccolis grown under different climate conditions.