Search

Eggplant fruits are normally harvested and marketed when they reach the commercial maturity, that precedes the physiological ripening when dramatic changes in taste, composition and peel color take place. The biochemical changes in fruit peel across the developmental stages, characterized also by a sizeable decrement of anthocyanins, were studied in four eggplant genotypes differing for fruit pigmentation. HPLC-DAD, HPLC-ESI-MS and NMR analyses identified naringenin chalcone and naringenin 7- O -glucoside as the main phenolic compounds in extracts from the physiological ripe stage, along with compounds tentatively identified as glycosylated naringenin chalcone, naringenin and kaempferol. On average, the levels of anthocyanins, responsible for the peel pigmentation, dropped by 75% during development, while, surprisingly, the level of total phenols showed a slight decrease of 16%, with a final concentration of more than 1000 mg/100g dw. RT-qPCR expression profiling of nine genes coding for enzymes putatively acting at different steps of the involved pathways showed modulation mostly consistent with the observed changes in phenolic composition, with a remarkable decrease in the activity of flavonol reductase and an increase in flavonol synthase during berry development. Antioxidant activity monitored by peroxyl scavenging was similar at all developmental stages while Fremy's analysis evidenced a slight decrement at full physiological ripening. These results are valuable to address the improvement of eggplant commercial fruit quality and the valorization of unmarketable physiological ripe fruits, especially for the newly accumulation of the health-promoting compounds chalcones and flavanones. [Display omitted] • Eggplant shows a dramatic change of phenolic composition during berry development. • Anthocyanins are substituted by chalcones at physiological ripening. • Transcript level of genes of the anthocyanin and chalcones pathways is in accordance with biochemical changes. • Antioxidant capacity of eggplant peel extracts slightly decreases along development. [ABSTRACT FROM AUTHOR]

Grafting of fruiting vegetables is an effective technique to overcome pests and diseases in modern cropping systems and it is often used to improve yield and fruit quality. Eggplant is an important vegetable crop that benefits significantly from grafting. In this regards, the exploitation, valorization and breeding of new rootstock genotypes as possible substitute to those commonly used ( Solanum torvum and tomato hybrids) would permit an intensive eggplant crop system in those situations where a rootstock rotation is required. In the present article, we study the effects of several potential rootstocks including both wild/allied species of eggplant [ S. torvum (STO), S. macrocarpon (SMA), S. aethiopicum (accession SASI), S. aethiopicum (accession SASa2), S. paniculatum (jurubeba) (SPA) and S. indicum (SIN)] and Msa 2/2 E7 and 460 CAL. eggplant hybrids on plant vigor, yield and fruit characteristics of eggplant F 1 hybrid (‘Birgah’), in two spring-summer growing seasons (2014 and 2015). SPA and the hybrids Msa 2/2 E7 and 460 CAL. displayed a high percentage of grafting success. ‘Birgah’ scion grafted onto the two above-mentioned rootstocks showed a notable vigour and yield. Both rootstocks did not promote any unfavorable effects on apparent fruit quality traits and overall fruit composition. Furthermore, the concentration of glycoalkaloids in the fruit remained below the recommended safety value (200 mg/100 g of dw). These results suggest that SPA and Msa 2/2 E7 and 460 CAL. eggplant hybrids might represent a potential rootstock alternative to S. torvum . [ABSTRACT FROM AUTHOR]

Physico-chemical traits of three eggplant genotypes (“Tunisina”, “Buia” and “L 305”) were evaluated before and after two cooking treatments (grilling and boiling). Different genotypes revealed different changes after cooking, with “Tunisina” showing a better retention of phytochemicals with respect to other two genotypes. The main physical phenomena were water loss during grilling, and dry matter loss after boiling. Chlorogenic acid, the main phenolic in eggplant, resulted higher in grilled samples, while delphinidin glycosides resulted more retained in boiled samples. Glycoalkaloids, thiols and biogenic amines were generally stable, while 5-hydroxy-methyl-furfural was found only in grilled samples. Interestingly, Folin–Ciocalteu index and free radical scavenging capacity, measured with three different assays, were generally increased after cooking, with a greater formation of antioxidant substances in grilled samples. NMR relaxation experiments clarified the hypothesis about the changes of eggplant compounds in terms of decomposition of larger molecules and production of small ones after cooking. [ABSTRACT FROM AUTHOR]

Abstract: The rice Osmyb4 gene, coding for a MYB transcription factor, is expressed at low levels in rice coleoptiles under normal conditions and strongly induced at 4°C. Its overexpression in Arabidopsis thaliana plants increases biotic and abiotic stress tolerance and results in the accumulation of several metabolites, essential in defence response. The heterologous expression of the Myb4 transcription factor represents a promising potential approach to improve stress tolerance in crops, avoiding endogenous mechanisms that often co-suppress the transgene of interest. In order to explore the potential of the Osmyb4 gene to enhance tolerance toward multiple stresses in different host plant genomes, we generated transgenic tomato (Solanum lycopersicum L. cv. Tondino) plants. Like Arabidopsis, tomato plants overexpressing Osmyb4 acquired a higher tolerance to drought stress and to virus disease. However, the transgenic plants did not appear to be more cold tolerant than the WT, in any tested condition. The data obtained indicate that the specificity and the degree of Osmyb4 activity depend on the host genomic background. [Copyright &y& Elsevier]

Abstract: Accessions of Solanum torvum SW, a wild relative of eggplant, were collected in Java Island, Indonesia, and assessed for morphology, fertility, levels of resistance against both Ralstonia solanacearum and Fusarium oxysporum f. sp. melongenae, as well as the genetic diversity by using RAPD and I-SSR markers. When grown to maturity in the field in Bogor, Indonesia, plants were very vigorous and showed a high polymorphism in all characters examined among the accessions, except for the stem diameter and the number of branches. The relatively high heterogeneity in morphology and fertility could not be related to the geographical origin of the accessions surveyed, and was not corroborated by genetic analysis. By using RAPD markers, 8.4% polymorphism were detected in two genotypes (BML and BG1) among the 11 accessions analysed, whereas screening with I-SSR markers has resulted in 3.3% polymorphism in three accessions, BG1, CN1 and CN2. This therefore gives a global 4.7% polymorphism, individualising only four accessions among the 11 tested. Twenty nine accessions of S. torvum and eggplant, cv Pusa Purple Long used as positive control, were evaluated for resistance to R. solanacearum (race 1 biovar 3, strain T926) in the greenhouse in Bogor. All inoculated plants of eggplant died within 2 weeks. Bacterial wilt symptoms occurred on lower leaves of S. torvum plants tested without however causing any plant death. The presence of bacteria, serologically detected in roots of symptomless plants, suggested S. torvum to be tolerant to R. solanacearum. A sample of 10 accessions was shown to be highly resistant to an Italian isolate of F. oxysporum f. sp. Melongena, while the cultivated eggplant, line Tina used as positive control, died within 2 weeks after inoculation. The low levels of genetic diversity of Javanese accessions of S. torvum and their relatively homogeneous response in tolerance and resistance to bacterial and fungal wilts are discussed, respectively. [Copyright &y& Elsevier]