Water deficit is a severe environmental stress and the major constraint on plant productivity with an evident effect on plant growth. The aim of this work was to study Triticum and Aegilops seedlings differing in their response to drought stress at the physiological and molecular levels. The identification of resistant and sensitive genotypes was firstly based on the relative water content (RWC) measurement. Further characterization of genotypes contrasting in their response to water stress was performed at the physiological level by determination of RWC, water loss rate (WLR) and free proline content after different hours of dehydration. Modification in the expression level of five dehydrin (DHN) genes was also analysed by reverse transcription–polymerase chain reaction (RT‐PCR). Five cDNAs coding for different DHNs were identified and characterized. These genes are not expressed in the well‐watered plants, but only in the stressed plants. Four of these cDNAs are related to novel DHN sequences. The results obtained clearly indicate a relation between the expression of these genes and tissue water content. In particular, in the resistant genotypes the expression of DHN genes is initiated even though tissue hydration levels are still high, indicating also in wheat the involvement of these proteins in water retention.

Betacyanin (betanin), total phenolics, vitamin C and antioxidant capacity (by Trolox-equivalent antioxidant capacity (TEAC) and oxygen radical absorbance capacity (ORAC) assays) were investigated in two differently colored cactus pear (Opuntia ficus-indica (L.) Mill.) genotypes, one with purple fruit and the other with orange fruit, from the Salento area, in Apulia (South Italy). In order to quantitate betanin in cactus pear fruit extracts (which is difficult by HPLC because of the presence of two isomers, betanin and isobetanin, and the lack of commercial standard with high purity), betanin was purified from Amaranthus retroflexus inflorescence, characterized by the presence of a single isomer. The purple cactus pear variety showed very high betanin content, with higher levels of phenolics, vitamin C, and antioxidant capacity (TEAC) than the orange variety. These findings confirm the potential for exploiting the autochthonous biodiversity of cactus pear fruits. In particular, the purple variety could be an interesting source of colored bioactive compounds which not only have coloring potential, but are also an excellent source of dietary antioxidant components which may have beneficial effects on consumers’ health.

In the recent years many studies on anthocyanins have revealed their strong antioxidant activity and their possible use as chemotherapeutics. The finding that sour cherries (Prunus cerasus L) (also called tart cherries) contain high levels of anthocyanins that possess strong antioxidant and anti‐inflammatory properties has attracted much attention to this species. Here we report the preliminary results of the induction of anthocyanin biosynthesis in sour cherry callus cell cultures. The evaluation and characterization of the in vitro produced pigments are compared to those of the anthocyanins found in vivo in fruits of several sour cherry cultivars. Interestingly, the anthocyanin profiles found in whole fruit extracts were similar in all tested genotypes but were different with respect to the callus extract. The evaluation of antioxidant activity, performed by ORAC and TEAC assays, revealed a relatively high antioxidant capacity for the fruit extracts (from 1145 to 2592 μmol TE/100 g FW) and a lower one for the callus extract (688 μmol TE/100 g FW).

Anthocyanins, the naturally occurring pigments responsible for most red to blue colours of flowers, fruits and vegetables, have also attracted interest because of their potential health effects. With the aim of contributing to major insights into their structure–activity relationship (SAR), we have evaluated the radical scavenging and biological activities of selected purified anthocyanin samples (PASs) from various anthocyanin-rich plant materials: two fruits (mahaleb cherry and blackcurrant) and two vegetables (black carrot and “Sun Black” tomato), differing in anthocyanin content (ranging from 4.9 to 38.5 mg/g DW) and molecular structure of the predominant anthocyanins. PASs from the abovementioned plant materials have been evaluated for their antioxidant capacity using Trolox Equivalent Antioxidant Capacity (TEAC) and Oxygen Radical Absorbance Capacity (ORAC) assays. In human endothelial cells, we analysed the anti-inflammatory activity of different PASs by measuring their effects on the expression of endothelial adhesion molecules VCAM-1 and ICAM-1. We demonstrated that all the different PASs showed biological activity. They exhibited antioxidant capacity of different magnitude, higher for samples containing non-acylated anthocyanins (typical for fruits) compared to samples containing more complex anthocyanins acylated with cinnamic acid derivatives (typical for vegetables), even though this order was slightly reversed when ORAC assay values were expressed on a molar basis. Concordantly, PASs containing non-acylated anthocyanins reduced the expression of endothelial inflammatory antigens more than samples with aromatic acylated anthocyanins, suggesting the potential beneficial effect of structurally diverse anthocyanins in cardiovascular protection.

Recent studies have shown that marine algae represent a great source of natural compounds with several properties. The lipidic extract of the seaweed Chaetomorpha linum (Chlorophyta, Cladophorales), one of the dominant species in the Mar Piccolo of Taranto (Mediterranean, Ionian Sea), revealed an antibacterial activity against Vibrio ordalii and Vibrio vulnificus, common pathogens in aquaculture, suggesting its potential employment to control fish and shellfish diseases due to vibriosis and to reduce the public health hazards related to antibiotic use in aquaculture. This extract showed also an antioxidant activity, corresponding to 170.960 ± 16. mmol Trolox equivalent/g (oxygen radical absorbance capacity assay—ORAC) and to 30.554 ± 2.30 mmol Trolox equivalent/g (Trolox equivalent antioxidant capacity assay—TEAC). The chemical characterization of the extract, performed by 1D and 2D NMR spectroscopy, highlighted the presence of free, saturated (SAFAs), unsaturated (UFAs) and polyunsaturated (PUFAs) fatty acids. The high content of ω-6 and ω-3 PUFAs confirmed also by gas chromatography indicates the potentiality of this algal species in the production of fortified food. The antibacterial activity seems related to the presence of linolenic acid present at high density, while the antioxidant activity could be likely ascribable to molecules such as carotenoids and chlorophylls (characterized also by thin-layer chromatography), known for this property. The presence of polyhydroxybutyrate, a biopolymer with potentiality in the field of biodegradable bioplastics was also detected. The exploitation of C. linum for a future biotechnological application is also encouraged by the results from a first attempt of cultivating this species in an integrated multi-trophic aquaculture (IMTA) system.