Enhancing the nutritional value of sweet bell pepper through moderate NaCl salinity.

Salinity presents a significant obstacle to crop productivity, particularly in dry and semi-arid regions. Sweet bell pepper (Capsicum annuum L.), a widely grown and consumed horticultural crop, is especially vulnerable to salinity. Consequently, it is vital to determine the salinity threshold that impacts bell pepper growth and quality, enabling sustainable production in salinized areas. This study aimed to evaluate the effects of varying sodium chloride concentrations (0, 50, and 75 mM) on bell pepper growth, nutritional value, and phytochemical composition, aiming to identify the adaptable threshold in salinized environments. The results suggested that the application of 75 mM NaCl not only had no adverse impact on fruit quality in terms of biomolecules and phytochemicals but also led to significant improvements. Specifically, under these conditions, there was a remarkable increase, in respect to control, in total protein (TPRO by 50 %), total carbohydrates (TCARB by 18 %), lycopene (LIC by 68 %), total Carotenoids (TCAR by 13 %), and total phenols (TPHE by 18 %) in terms of antioxidants.In contrast, the content of ascorbic acid and antioxidant activities remained consistent. Moderate salt stress exhibited the most positive influence on sweet bell pepper quality, leading to higher concentrations of essential nutrients and nutraceutical compounds, including minerals, phenolic acids, and flavonoids.

Recycling agricultural, municipal and industrial pollutant wastes into fertilizers for a sustainable healthy food production.

This work was focused on recycling different typology of pollutant wastes (olive pomace and orange residues; municipal wastes and sulphur residue of hydrocarbon refining processes) with the triple objectives of limiting wastes in landfill, reducing greenhouse gas emission and producing organic-mineral fertilizers. The environmental risks and benefits of the whole process have been considered. The specific objectives were: 1) innovation in waste management techniques by reducing the accumulation of different typology of wastes using a unique process 2) verifying efficiency of the obtained organic-mineral fertilizers on soil and plant growth 3) improving soil and crop quality relating wastes to food, economy and environment. Sulphur-based pads improved soil quality mostly when contained orange residues. Onion and Garlic grew better in presence of sulphur-based pads (+20%), and mostly when pads contained orange residues (+45%). Onion and Garlic quality, in terms of antioxidant compounds and antioxidant capacity, increased in presence of sulphur-based pads (+30%) mostly when orange residues were present in the pads (+90%). In short, in addition to the environmental advantages, numerous economic benefits coming from the decrease in the production and use of chemical fertilizers, the reduction of costs for landfilling and the gain rising from the sale of the new fertilizers produced, emerged.

Bio-priming mitigates detrimental effects of salinity on maize improving antioxidant defense and preserving photosynthetic efficiency.

Salinity is an abiotic stress which seriously affects crop production over the world, particularly in arid and semi-arid regions, with harmful effects on germination, growth and yield. Maize (Zea mays L.), cultivated in a wide spectrum of soil and climatic conditions, is the third most important cereal crop after rice and wheat, moderately sensitive to salt stress. A saline level more than 250 mM NaCl damages maize plants, causing severe wilting. In this study, the effects of hydro-priming (distilled water) and bio-priming (Rosmarinus officinalis L. and Artemisia L. leaf extracts) on seed germination and seedling growth of maize, under 100 mM NaCl salinity were investigated. The factorial experiments were carried out in greenhouse under controlled condition (25 °C in 12/12 h day/night) based on a completely randomized design with three replicates. Results showed that both hydro- and bio-priming increased germination percentage and germination indexes in maize seeds. Rosmarinus extract was the most effective in inducing salt resistance in 30 days old seedlings, with beneficial effects in the strengthening of the antioxidant system and in the maintenance of a higher photosynthetic efficiency under salt stress condition.

Phenotypic and metabolic responses to drought and salinity of four contrasting lentil accessions.

Drought and salinity are among the major abiotic stresses which, often inter-relatedly, adversely affect plant growth and productivity. Plant stress responses depend on the type of stress, on its intensity, on the species, and also on the genotype. Different accessions of a species may have evolved different mechanisms to cope with stress and to complete their life cycles. This study is focused on lentil, an important Mediterranean legume with high quality protein for the human diet. The effects of salinity and drought on germination and early growth of Castelluccio di Norcia (CAST), Pantelleria (PAN), Ustica (UST), and Eston (EST) accessions were evaluated to identify metabolic and phenotypic traits related to drought and/or salinity stress tolerance. The results showed a relationship between imposed stresses and performance of the cultivars. According to germination frequencies, the accession ranking was as follows: NaCl resistant > susceptible, PAN > UST > CAST > EST; polyethylene glycol (PEG) resistant > susceptible, CAST > UST > EST > PAN. Seedling tolerance rankings were: NaCl resistant > susceptible, CAST ≈ UST > PAN ≈ EST; PEG resistant > susceptible, CAST > EST ≈ UST > PAN. Changes in the metabolite profiles, mainly quantitative rather than qualitative, were observed in the same cultivar in respect to the treatments, and among the cultivars under the same treatment. Metabolic differences in the stress tolerance of the different genotypes were related to a reduction in the levels of tricarboxylic acid (TCA) cycle intermediates. The relevant differences, between the most NaCl-tolerant genotype (PAN) and the most sensitive one (EST) were related to the decrease in the threonic acid level. Stress-specific metabolite indicators were also identified: ornithine and asparagine as markers of drought stress and alanine and homoserine as markers of salinity stress.

Effect of saline water on seed germination and early seedling growth of the halophyte quinoa.

Salinization is increasing on a global scale, decreasing average yields for most major crop plants. Investigations into salt resistance have, unfortunately, mainly been focused on conventional crops, with few studies screening the potential of available halophytes as new crops. This study has been carried out to investigate the mechanisms used by quinoa, a facultative halophytic species, in order to cope with high salt levels at various stages of its development. Quinoa is regarded as one of the crops that might sustain food security in this century, grown primarily for its edible seeds with their high protein content and unique amino acid composition. Although the species has been described as a facultative halophyte, and its tolerance to salt stress has been investigated, its physiological and molecular responses to seawater (SW) and other salts have not been studied. We evaluated the effects of SW and different salts on seed germination, seedling emergence and the antioxidative pathway of quinoa. Seeds were germinated in Petri dishes and seedlings grown in pots with SW solutions (25, 50, 75 and 100 %) and NaCl, CaCl2, KCl and MgCl2 individually, at the concentrations in which they are present in SW. Our results demonstrated that all salts, at lower concentrations, increased the germination rate but not the germination percentages, compared with control (pure water). Conversely, seedlings were differently affected by treatments in respect to salt type and concentration. Growth parameters affected were root and shoot length, root morphology, fresh and dry weight, and water content. An efficient antioxidant mechanism was present in quinoa, activated by salts during germination and early seedling growth, as shown by the activities of antioxidant enzymes. Total antioxidant capacity was always higher under salt stress than in water. Moreover, osmotic and ionic stress factors had different degrees of influence on germination and development.

The auxin-like activity of humic substances is related to membrane interactions in carrot cell cultures.

A detailed characterization of two humic fractions was performed: One with low relative molecular mass (LMr<3,500 Da) and one with high relative molecular mass (HMr>3,500 Da). Distinct (1)H NMR spectroscopic patterns were observed for the two fractions. HMr showed an aromatic proton region, an intense and broad region (3.0-5.0 ppm) attributed to sugar-like and polyether components, and an intense doublet at 1.33 ppm (identified as protons of the beta-CH(3) in lactate). In contrast, LMr did not show resonances due to aromatic protons and was characterized by a broad unresolved region, assigned to sugar-like components. The (13)C NMR spectra showed that the LMr humic fraction was richer in carboxylic and aliphatic C groups compared to HMr fraction. These substances were fluorescein-labeled [fluorescein isothiocyanate (FITC)], and their interaction with carrot cells in culture was monitored for 10 d, and compared to FITC-indole-3-acetic acid (IAA) to clarify their mechanisms of biological activity. After different incubation times, fluorescein staining of carrot cells and decrease of fluorescein concentration in the culture medium were evaluated. Fluorescent membrane staining was only present in IAA and the LMr humic fraction treated cell cultures. A consequential decrease of fluorescein concentration in the culture media was also observed. Pretreatment of carrot cells with unconjugated IAA or LMr humic fraction markedly reduced fluorescein staining of both FITC-IAA and FITC-LMr humic fraction. Blocking tests gave indirect evidence of possible binding of the LMr humic fraction to IAA cell membrane receptors. These results indicate that the two humic fractions behave differently. Only LMr humic fraction, like IAA, interacts with cellular membranes in carrot cell cultures.