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Background: Genetic engineering of parthenocarpy confers to horticultural plants the ability to produce fruits under environmental conditions that curtail fruit productivity and quality. The DefH9-iaaM transgene, whose predicted action is to confer auxin synthesis specifically in the placenta, ovules and derived tissues, has been shown to confer parthenocarpy to several plant species (tobacco, eggplant, tomato) and varieties. Results: UC82 tomato plants, a typical cultivar used by the processing industry, transgenic for the DefH9-iaaM gene produce parthenocarpic fruits that are malformed. UC82 plants transgenic for the DefH9-RI-iaaM, a DefH9-iaaM derivative gene modified in its 5'ULR by replacing 53 nucleotides immediately upstream of the AUG initiation codon with an 87 nucleotides-long sequence derived from the rolA intron sequence, produce parthenocarpic fruits of high quality. In an in vitro translation system, the iaaM mRNA, modified in its 5'ULR is translated 3-4 times less efficiently than the original transcript. An optimal expressivity of parthenocarpy correlates with a reduced transgene mRNA steady state level in DefH9-RI-iaaM flower buds in comparison to DefH9-iaaM flower buds. Consistent with the known function of the iaaM gene, flower buds transgenic for the DefH9-RI-iaaM gene contain ten times more IAA than control untransformed flower buds, but five times less than DefH9-iaaM flower buds. Conclusions:: By using an auxin biosynthesis transgene downregulated at the post-transcriptional level, an optimal expressivity of parthenocarpy has been achieved in a genetic background not suitable for the original transgene. Thus, the method allows the generation of a wider range of expressivity of the desired trait in transgenic plants. [ABSTRACT FROM AUTHOR]

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]

Eggplant (Solanum melongena L.) yield is highly sensitive to N fertilization, the excessive use of which is responsible for environmental and human health damage. Lowering N input together with the selection of improved Nitrogen‐Use‐Efficiency (NUE) genotypes, more able to uptake, utilize, and remobilize N available in soils, can be challenging to maintain high crop yields in a sustainable agriculture. The aim of this study was to explore the natural variation among eggplant accessions from different origins, in response to Low (LN) and High (HN) Nitrate (NO3‐) supply, to identify NUE‐contrasting genotypes and their NUE‐related traits, in hydroponic and greenhouse pot experiments. Two eggplants, AM222 and AM22, were identified as N‐use efficient and inefficient, respectively, in hydroponic, and these results were confirmed in a pot experiment, when crop yield was also evaluated. Overall, our results indicated the key role of N‐utilization component (NUtE) to confer high NUE. The remobilization of N from leaves to fruits may be a strategy to enhance NUtE, suggesting glutamate synthase as a key enzyme. Further, omics technologies will be used for focusing on C‐N metabolism interacting networks. The availability of RILs from two other selected NUE‐contrasting genotypes will allow us to detect major genes/quantitative trait loci related to NUE. [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]

Arabidopsis thaliana At4g17830 codes for a protein showing sequence similarity with the Escherichia coli N-acetylornithine deacetylase (EcArgE), an enzyme implicated in the linear ornithine (Orn) biosynthetic pathway. In plants, Nacetylornithine deacetylase (NAOD) activity has yet to be demonstrated; however, At4g17830-silenced and mutant (atnaod) plants display an impaired reproductive phenotype and altered foliar levels of Orn and polyamines (PAs). Here, we showed the direct connection between At4g17830 function and Orn biosynthesis, demonstrating biochemically that At4g17830 codes for a NAOD. These results are the first experimental proof that Orn can be produced in Arabidopsis via a linear pathway. In this study, to identify the role of AtNAOD in reproductive organs, we carried out a transcriptomic analysis on atnaod mutant and wild-type flowers. In the atnaod mutant, the most relevant effects were the reduced expression of cysteine-rich peptidecoding genes, known to regulate male-female cross-talk during reproduction, and variation in the expression of genes involved in nitrogen:carbon (N:C) status. The atnaod mutant also exhibited increased levels of sucrose and altered sensitivity to glucose. We hypothesize that AtNAOD participates in Orn and PA homeostasis, contributing to maintain an optimal N:C balance during reproductive development. [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]

The development of inexpensive and highly productive biomass sources of biofuel is a priority in global climate change biology. Arundo donax, also known as the giant reed, is recognized as one of the most promising nonfood bioenergy crops in Europe. Despite its relevance, to date no genomic resources are available to support the characterization of the developmental, adaptive and metabolic traits underlying the high productivity of this nonmodel species. We hereby present the first report on the de novo assembly of bud, culm, leaf and root transcriptomes of A. donax, which can be accessed through a customized BLAST server () for mining and exploring the genetic potential of this species. Based on functional annotation and homology comparison to 19 prospective biofuel Poaceae species, we provide the first genomic view of this so far unexplored crop and indicate the model species with highest potential for comparative genomics approaches. The analysis of the transcriptome reveals strong differences in the enrichment of the Gene Ontology categories and the relative expression among different organs, which can guide future efforts for functional genomics or genetic improvement of A. donax. A set of homologs to key genes involved in lignin, cellulose, starch, lipid metabolism and in the domestication of other crops is discussed to provide a platform for possible enhancement of productivity and saccharification efficiency in A. donax. [ABSTRACT FROM AUTHOR]

Summary [ABSTRACT FROM AUTHOR]

MADS-box genes have been shown to play a role in the formation of fruits, both in Arabidopsis and in tomato. In peach, two C-class MADS-box genes have been isolated. Both of them are expressed during flower and mesocarp development. Here a detailed analysis of a gene that belongs to the PLENA subfamily of MADS-box genes is shown. The expression of this PLENA-like gene (PpPLENA) increases during fruit ripening, and its ectopic expression in tomato plants causes the transformation of sepals into carpel-like structures that become fleshy and ripen like real fruits. Interestingly, the transgenic berries constitutively expressing the PpPLENA gene show an accelerated ripening, as judged by the expression of genes that are important for tomato fruit ripening. It is suggested that PpPLENA might interfere with the endogenous activity of TAGL1, thereby activating the fruit ripening pathway earlier compared with wild-type tomato plants. [ABSTRACT FROM PUBLISHER]

Gene exchanges between Solanum melongena and its allied relative Solanum aethiopicum are a crucial prerequisite for introgression of useful traits from the allied species into the cultivated eggplant. In order to evaluate the extent of genetic recombination between the 2 species, biochemical and molecular markers were employed. A dihaploid population obtained through anther culture of the corresponding tetraploid somatic hybrids was genetically analyzed. The extent of disomic/ tetrasomic inheritance and segregation ratios of 3 isozyme systems and intersimple sequence repeat (ISSR) markers were evaluated. The dihaploids, being derived from microspores, allowed for simple, complete, and accurate analyses. The segregation of 280 ISSR markers (110 aethiopicum-specific, 104 melongena -specific, and 66 monomorphic) were evaluated in 71 dihaploids. According to the genetic constitution (simplex/duplex/triplex), almost 64% of the fragments revealed the tetrasomic and/or disomic inheritance. With regard to the assigned species-specific fragments, 68% and 4% were unambiguously the result of tetrasomic and disomic inheritance, respectively. Twenty-four of the 66 monomorphic ISSRs were inherited according to random chromatid segregation. The phenotypes of glucose-6-phosphate dehydrogenase (G-6 -PDH), 6-phosphogluconate dehydrogenase (6-PGDH), and shikimate dehydrogenase (SKDH) were studied in 70 dihaploids and inferences were made about the allelic state of their 5 loci. The isozyme markers segregated in the dihaploids in a distorted manner, their segregations did not fit in with any of the expected segregation ratios. However, tetrasomic inheritance might be suggested for G-6-PDH 2 and SKDH 1 loci. Our results demonstrated that gene exchanges occurred readily in the somatic hybrids between S. melongena and S. aethiopicum gr. Gilo. [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]