The contents of antioxidant nutritional compounds, total soluble phenolics (TSP), vitamin C, vitamin E, beta-carotene, and total carotenoids (TC), were correlated with the total antioxidant capacity (AOC) of hydrophilic (HPE) and lipophilic extracts (LPE) from eight horticultural crops, namely, guava, avocado, black sapote, mango, papaya, prickly pear fruit, cladodes, and strawberry. AOC was measured using six different assays: 2,2'-diphenyl-1-picrylhydrazyl (DPPH), N,N-dimethyl-p-phenylendiamine (DMPD), ferric-ion-reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC), Trolox equivalent antioxidant capacity (TEAC), and total oxidant scavenging capacity (TOSC). AOC values from HPE were about 95 times higher than LPE values. HPE of guava had the highest AOC value when evaluated with DMPD, DPPH, FRAP, TEAC, and TOSC assays, whereas with ORAC assay, black sapote had the highest value. HPE of papaya and prickly pear fruit presented the lowest AOC values with all assays. From HPE, vitamin C and TSP contents were highly correlated with AOC for all assays, while from LPE, TC and beta-carotene contents possessed a high correlation with AOC only in the DMPD assay.

Mangofruit has a relatively short storage life of about 2 to 3 weeks at 13C. In order to prolong the storage life of 'Haden' mangoes, fruit were coated with 3 concentrations (8,16 and 24 g.L-9 of the edible coating film "Sempefiesh " and then stored at 13C and 85% RH. Fruit were then evaluated every 4 days for up to 32 days for total soluble solidr (TSS), titratable acidity (TA), pH, firmness, weight loss, color of the skin, and ascorbic acid content. All 3 concentrations applied to the h i t affected j u i t ripening. TA, jirmness, and green color were higher in coated juit, and weight loss, SST, and pH were lower compared with the noncoatedBit. 'Sempei@esh'' had no efect on decay development. Ascorbic acid decreased in all storedfruit, but this decrease was slower in coatedjuit, and there were no significant differences between the different "Semper$-esh " concentrations.

A single copy of the N-acetyl-L-glutamate synthase gene (SlNAGS1) has been isolated from tomato. The deduced amino acid sequence consists of 604 amino acids and shows a high level of similarity to the predicted Arabidopsis NAGS1 and NAGS2 proteins. Furthermore, the N-terminus ArgB domain and the C-terminus ArgA domain found in SlNAGS1 are similar to the structural arrangements that have been reported for other predicted NAGS proteins. SlNAGS1 was expressed at high levels in all aerial organs, and at basic levels in seeds, whereas it was not detected at all in roots. SlNAGS1 transcript accumulation was noticed transiently in tomato fruit at the red-fruit stage. In addition, an increase of SlNAGS1 transcripts was detected in mature green tomato fruit within the first hour of exposure to low oxygen concentrations. Transgenic Arabidopsis plants have been generated expressing the SlNAGS1 gene under the control of the cauliflower mosaic virus (CaMV) 35S promoter. Three homozygous transgenic lines expressing the transgene (lines 1-7, 3-8, and 6-5) were evaluated further. All three transgenic lines showed a significant accumulation of ornithine in the leaves with line 3-8 exhibiting the highest concentration. The same lines demonstrated higher germination ability compared to wild-type (WT) plants when subjected to 250 mM NaCl. Similarly, mature plants of all three transgenic lines displayed a higher tolerance to salt and drought stress compared to WT plants. Under most experimental conditions, transgenic line 3-8 performed best, while the responses obtained from lines 1-7 and 6-5 depended on the applied stimulus. To our knowledge, this is the first plant NAGS gene to be isolated, characterized, and genetically modified.