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A broad diversity of phenotypes are available within the cassava germplasm collections. The phenotypes include improved nutritional, starch or culinary root quality as well as abiotic and biotic resistance properties. Some of these traits can be found naturally occurring in cassava landraces, whereas others are the result of targeted breeding efforts. For future breeding programmes it is important to know the underlying mechanisms of these desirable traits. Metabolomics can assist in the elucidation of these mechanisms by measuring the end products of the cellular processes conferring the traits of interest. The present study focused on the comparison of two or more variants of the same trait such as high and low culinary quality or resistance and susceptibility to thrips. Overall, eight different traits were assessed. Results showed that amino acids and umami compounds were associated with superior culinary attributes and the phenylpropanoid superpathway plays an important role in pest resistance. Furthermore, the data highlighted a low chemodiversity in African cassavas and that the source-sink relation was still active at the harvest stage. [ABSTRACT FROM AUTHOR]

• Wild, landrace and bred potato varieties show distinct metabolite profiles. • Group specific metabolite compositions are maintained upon cooking. • Bred native hybrids showed no significant change of Vitamin A precursors. • Accessions with distinct traits were identified for breeding purposes. Elucidating and improving the nutritional value of staple crops is an important focus in breeding programs. Hence, wild and cultivated potatoes have been metabolite profiled to assess metabolic plasticity present in potato tubers and changes that occur in these after cooking. The present data highlighted metabolic similarities of certain wild species to breeding lines, indicating preference during domestication. In the case of potato, the cooking process has to be taken into consideration for the assessment of nutritional quality. The degree of nutritional change during cooking depends on several factors including cooking method, stability of metabolites with nutritional properties and chemotype of the varietal matrix. The differences between raw and boiled tubers were similar within each germplasm group. No notable distinctions of total phenolic levels could be observed within germplasm groups, whereas total carotenoids and glycoalkaloids were significantly decreased. Genotypes/cultivars with notable changes upon cooking distinguished them within their genotype group. [ABSTRACT FROM AUTHOR]

The evaluation of plant-based feedstocks is an important aspect of biorefining. Nicotiana glauca is a solanaceous, non-food crop that produces large amounts of biomass and is well adapted to grow in suboptimal conditions. In the present article, compatible sequential solvent extractions were applied to N. glauca leaves to enable the generation of enriched extracts containing higher metabolite content comparing to direct leaf extracts. Typically, between 60 to 100 metabolite components were identified within the fractions. The occurrence of plant fatty acids, fatty acid alcohols, alkanes, sterols and terpenoids was detected by gas liquid chromatography-mass spectrometry (GC-MS) and metabolite identification was confirmed by comparison of physico-chemical properties displayed by available authentic standards. Collectively, co-products such waxes, oils, fermentable sugars, and terpenoids were all identified and quantified. The enriched fractions of N. glauca revealed a high level of readily extractable hydrocarbons, oils and high value co-products. In addition, the saccharification yield and cell wall composition analyses in the stems revealed the potential of the residue material as a promising lignocellulosic substrate for the production of fermentable sugars. In conclusion a multifractional cascade for valuable compounds/commodities has been development, that uses N. glauca biomass. These data have enabled the evaluation of N. glauca material as a potential feedstock for biorefining., (© 2024. The Author(s).)

Exhaustive analysis of genetically modified crops over multiple decades has increased societal confidence in the technology. New Plant Breeding Techniques are now emerging with improved precision and the ability to generate products containing no foreign DNA and mimic/replicate conventionally bred varieties. In the present study, metabolomic analysis was used to compare (i) tobacco genotypes with and without the CRISPR associated protein 9 (Cas9), (ii) tobacco lines with the edited and non-edited DE-ETIOLATED-1 gene without phenotype and (iii) leaf and fruit tissue from stable non-edited tomato progeny with and without the Cas9. In all cases, multivariate analysis based on the difference test using LC-HRMS/MS and GC-MS data indicated no significant difference in their metabolomes. The variations in metabolome composition that were evident could be associated with the processes of tissue culture regeneration and/or transformation (e.g. interaction with Agrobacterium). Metabolites responsible for the variance included quantitative changes of abundant, well characterised metabolites such as phenolics (e.g. chlorogenic acid) and several common sugars such as fructose. This study provides fundamental data on the characterisation of gene edited crops, that are important for the evaluation of the technology and its assessment. The approach also suggests that metabolomics could contribute to routine product-based analysis of crops/foods generated from New Plant Breeding approaches., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Many highly valued chemicals in the pharmaceutical, biotechnological, cosmetic, and biomedical industries belong to the terpenoid family. Biosynthesis of these chemicals relies on polymerization of Isopentenyl di-phosphate (IPP) and/or dimethylallyl diphosphate (DMAPP) monomers, which plants synthesize using two alternative pathways: a cytosolic mevalonic acid (MVA) pathway and a plastidic methyleritritol-4-phosphate (MEP) pathway. As such, developing plants for use as a platform to use IPP/DMAPP and produce high value terpenoids is an important biotechnological goal. Still, IPP/DMAPP are the precursors to many plant developmental hormones. This creates severe challenges in redirecting IPP/DMAPP towards production of non-cognate plant metabolites. A potential solution to this problem is increasing the IPP/DMAPP production flux in planta . Here, we aimed at discovering, understanding, and predicting the effects of increasing IPP/DMAPP production in plants through modelling. We used synthetic biology to create rice lines containing an additional ectopic MVA biosynthetic pathway for producing IPP/DMAPP. The rice lines express three alternative versions of the additional MVA pathway in the plastid, in addition to the normal endogenous pathways. We collected data for changes in macroscopic and molecular phenotypes, gene expression, isoprenoid content, and hormone abundance in those lines. To integrate the molecular and macroscopic data and develop a more in depth understanding of the effects of engineering the exogenous pathway in the mutant rice lines, we developed and analyzed data-centric, line-specific, multilevel mathematical models. These models connect the effects of variations in hormones and gene expression to changes in macroscopic plant phenotype and metabolite concentrations within the MVA and MEP pathways of WT and mutant rice lines. Our models allow us to predict how an exogenous IPP/DMAPP biosynthetic pathway affects the flux of terpenoid precursors. We also quantify the long-term effect of plant hormones on the dynamic behavior of IPP/DMAPP biosynthetic pathways in seeds, and predict plant characteristics, such as plant height, leaf size, and chlorophyll content from molecular data. In addition, our models are a tool that can be used in the future to help in prioritizing re-engineering strategies for the exogenous pathway in order to achieve specific metabolic goals., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Basallo, Perez, Lucido, Sorribas, Marin-Saguino, Vilaprinyo, Perez-Fons, Albacete, Martínez-Andújar, Fraser, Christou, Capell and Alves.)

Natural and social science studies have commonly referenced a 'typical' or 'habitual' Nigerian diet, without defining what such a diet entails. Our study, based on a systematic review of the existing literature and an analysis of household-level survey data, describes the general outline of a common Nigerian diet and how it varies based on spatial, demographic, and socio-economic characteristics. We further try to establish whether Nigeria has embarked on a dietary transition common in most modern economies, marked by a greater consumption of processed foods, fats, and sugar at the expense of traditional whole cereals and pulses. We conclude that while a traditional Nigerian diet is still relatively healthy from an international perspective, it has indeed been transitioning, with an increasing inclusion of high-energy, high-fat, and high-sugar processed foods and a related growing incidence of overweight, obesity, and diet-related non-communicable diseases.

Isoprenoids are natural products derived from isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP). In plants, these precursors are synthesized via the cytosolic mevalonate (MVA) and plastidial methylerythritol phosphate (MEP) pathways. The regulation of these pathways must therefore be understood in detail to develop effective strategies for isoprenoid metabolic engineering. We hypothesized that the strict regulation of the native MVA pathway could be circumvented by expressing an ectopic plastidial MVA pathway that increases the accumulation of IPP and DMAPP in plastids. We therefore introduced genes encoding the plastid-targeted enzymes HMGS, tHMGR, MK, PMK and MVD and the nuclear-targeted transcription factor WR1 into rice and evaluated the impact of their endosperm-specific expression on (1) endogenous metabolism at the transcriptomic and metabolomic levels, (2) the synthesis of phytohormones, carbohydrates and fatty acids, and (3) the macroscopic phenotype including seed morphology. We found that the ectopic plastidial MVA pathway enhanced the expression of endogenous cytosolic MVA pathway genes while suppressing the native plastidial MEP pathway, increasing the production of certain sterols and tocopherols. Plants carrying the ectopic MVA pathway only survived if WR1 was also expressed to replenish the plastid acetyl-CoA pool. The transgenic plants produced higher levels of fatty acids, abscisic acid, gibberellins and lutein, reflecting crosstalk between phytohormones and secondary metabolism., (© 2022. The Author(s).)

Biochemical characterisation of germplasm collections and crop wild relatives (CWRs) facilitates the assessment of biological potential and the selection of breeding lines for crop improvement. Data from the biochemical characterisation of staple root, tuber and banana (RTB) crops, i.e. banana ( Musa spp.), cassava ( Manihot esculenta ), potato ( Solanum tuberosum ), sweet potato ( Ipomoea batatas ) and yam ( Dioscorea spp .), using a metabolomics approach is presented. The data support the previously published research article "Metabolite database for root, tuber, and banana crops to facilitate modern breeding in understudied crops" (Price et al., 2020) [1]. Diversity panels for each crop, which included a variety of species, accessions, landraces and CWRs, were characterised. The biochemical profile for potato was based on five elite lines under abiotic stress. Metabolites were extracted from the tissue of foliage and storage organs (tuber, root and banana pulp) via solvent partition. Extracts were analysed via a combination of liquid chromatography - mass spectrometry (LC-MS), gas chromatography (GC)-MS, high pressure liquid chromatography with photodiode array detector (HPLC-PDA) and ultra performance liquid chromatography (UPLC)-PDA. Metabolites were identified by mass spectral matching to in-house libraries comprised from authentic standards and comparison to databases or previously published literature., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2022 Published by Elsevier Inc.)

The bZIP transcription factor (TF) SlTGA2.2 was previously highlighted as a possible hub in a network regulating fruit growth and transition to ripening (maturation phase). It belongs to a clade of TFs well known for their involvement in the regulation of the salicylic acid-dependent systemic acquired resistance. To investigate if this TGA TF plays a role in tomato fruit growth and maturation, we took advantage of the fruit-specific SlPPC2 promoter (PPC2pro) to target the expression of a SlTGA2.2-SRDX chimeric repressor in a developmental window restricted to early fruit growth and maturation. Here, we show that this SlTGA2.2-SRDX repressor alters early fruit development and metabolism, including chloroplast number and structure, considerably extends the time necessary to reach the mature green stage and slows down fruit ripening. RNA sequencing and plant hormone analyses reveal that PPC2pro:SlTGA2.2-SRDX fruits are maintained in an immature stage as long as PPC2pro is active, through early modifications of plant hormonal signaling and down-regulation of MADS-RIN and NAC-NOR ripening regulators. Once PPC2pro becomes inactive and therefore SlTGA2.2-SRDX expression is reduced, ripening can proceed, albeit at a slower pace than normal. Altogether, this work emphasizes the developmental continuum between fruit growth, maturation and ripening and provides a useful tool to alter and study the molecular bases of tomato fruit transition to ripening., (© The Author(s) 2021. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Carotenoid biosynthesis has now been subjected to metabolic engineering for over two decades. The outputs clearly show that carotenoid formation is an integral component of metabolism. Perturbations can affect intermediary metabolism and other isoprenoids. The advances in omic technologies have enabled the quantitative assessment of changes in the transcriptome, proteome and metabolome in response to altered carotenoid biosynthesis. In the present article, the approaches and procedures relating to the capture of the metabolome in response to modulation of the carotenoid biosynthetic pathway are described. These data will contribute to the fundamental understanding of metabolic biology, underpinning future rationale design of New Plant Breeding Techniques (NPBTs) and associated regulatory affairs., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Carotenoid biosynthesis and sequestration in higher plants occurs in the plastid organelle. Among diverse germplasm collections displaying natural variation for carotenoids and outputs from metabolic engineering experiments it has become clear that plastid type and numbers can have important implications on the quantitative composition of carotenoids accumulating. Therefore, it is important to characterize these organelles to fully evaluate the potential of the germplasm to enhance carotenoids and create nutrient dense fruits and vegetables. In this article the procedures used to isolate sub-plastidial structures from carotenoid-rich Solanaceae fruits (tomato and Capsicum) are described., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Mass spectrometry-based metabolomics approaches can enable detection and quantification of many thousands of metabolite features simultaneously. However, compound identification and reliable quantification are greatly complicated owing to the chemical complexity and dynamic range of the metabolome. Simultaneous quantification of many metabolites within complex mixtures can additionally be complicated by ion suppression, fragmentation and the presence of isomers. Here we present guidelines covering sample preparation, replication and randomization, quantification, recovery and recombination, ion suppression and peak misidentification, as a means to enable high-quality reporting of liquid chromatography- and gas chromatography-mass spectrometry-based metabolomics-derived data.

Over the recent years, Nicotiana benthamiana has gained great importance as a chassis for the production of high value, low volume pharmaceuticals and/or active pharmaceutical ingredients (APIs). The process involving infiltration of the N. benthamiana leaves with Agrobacterium spp, harbouring vectors with the gene of interest, facilitates transient expression. To date, little information is available on the effect of the agro-infiltration process on the metabolome of N. benthamiana, which is necessary to improve the process for large-scale, renewable manufacturing of high value compounds and medical products. Hence, the objective of the present study was to assess metabolic adaptation of N. benthamiana as a response to the presence of Agrobacterium. The present study elucidated changes of the steady-state metabolism in the agroinfiltrated leaf area, the area around the infection and the rest of the plant. Furthermore, the study discusses the phenotypic advantages of the N. benthamiana lab strain, optimised for agro-infiltration, compared to three other wild accessions. Results showed that the lab strain has a different metabolic composition and showed less alterations of the phenylpropanoid pathway and cell wall remodelling in the agroinfiltrated leaf areas, for example chlorogenic acid, cadaverine and C18:0-2-glycerol ester. In conclusion, both of these alterations present potential candidates to improve the phenotype of the N. benthamiana lab strain for a more efficient transient expression process.

Carotenoids are the pigments responsible for conferring the characteristic deep red colour to chilli pepper. The post-harvest retention of this colour is a key trait that governs the price of the produce. Determining colour retention and the associated underlying biochemical mechanisms are important issues that require investigation. In this present study, the ability of image analysis to determine colour change in ground chilli fruit was evaluated. This method enabled differentiation of extreme retention phenotypes whilst also reducing the duration of storage required to make accurate determinations. The analysis of volatiles indicated different levels of lipid and carotenoid derived volatiles in lines with different retention properties. Metabolite profiling of intermediary metabolism supported these findings, with increased levels of unsaturated fatty acids present in lines with low retention properties. Collectively, these data have led us to propose that in chilli fruit lipid peroxidation is one of the progenitors of carotenoid degradation., (© 2021 The Authors. Published by Elsevier Ltd.)

Cyanobacteria are photosynthetic prokaryotes that perform oxygenic photosynthesis. Due to their ability to use the photon energy of sunlight to fix carbon dioxide into biomass, cyanobacteria are promising hosts for the sustainable production of terpenoids, also known as isoprenoids, a diverse class of natural products with potential as advanced biofuels and high-value chemicals. However, the cyanobacterial enzymes involved in the biosynthesis of the terpene precursors needed to make more complicated terpenoids are poorly characterized. Here we show that the predicted type II prenyltransferase CrtE encoded by the model cyanobacterium Synechococcus sp. PCC 7002 is homodimeric and able to synthesize C20-geranylgeranyl pyrophosphate (GGPP) from C5-isopentenyl pyrophosphate (IPP) and C5-dimethylallyl pyrophosphate (DMAPP). The crystal structure of CrtE solved to a resolution of 2.7 Å revealed a strong structural similarity to the large subunit of the heterodimeric geranylgeranyl pyrophosphate synthase 1 from Arabidopsis thaliana with each subunit containing 14 helices. Using mutagenesis, we confirmed that the fourth and fifth amino acids (Met-87 and Ser-88) before the first conserved aspartate-rich motif (FARM) play important roles in controlling chain elongation. While the WT enzyme specifically produced GGPP, variants M87F and S88Y could only generate C15-farnesyl pyrophosphate (FPP), indicating that residues with large side chains obstruct product elongation. In contrast, replacement of M87 with the smaller Ala residue allowed the formation of the longer C25-geranylfarnesyl pyrophosphate (GFPP) product. Overall, our results provide new structural and functional information on the cyanobacterial CrtE enzyme that could lead to the development of improved cyanobacterial platforms for terpenoid production., (Copyright © 2020 Feng, Morgan, Fraser, Hellgardt and Nixon.)

Bananas (Musa spp.) are consumed worldwide as dessert and cooking types. Edible banana varieties are for the most part seedless and sterile and therefore vegetatively propagated. This confers difficulties for breeding approaches against pressing biotic and abiotic threats and for the nutritional enhancement of banana pulp. A panel of banana accessions, representative of the diversity of wild and cultivated bananas, was analysed to assess the range of chemotypes available globally. The focus of this assessment was banana leaves at two growth stages (juvenile and pre-flowering), to see when during the plant growth metabolic differences can be established. The metabolic data corresponded to genomic trends reported in previous studies and demonstrated a link between metabolites/pathways and the genomes of M. acuminata and M. balbisiana. Furthermore, the vigour and resistance traits of M. balbisiana was connected to the phenolic composition and showed differences with the number of B genes in the hybrid accessions. Differences in the juvenile and pre-flowering data led to low correlation between the growth stages for prediction purposes.

Tomato ( Solanum lycopersicum ) is a globally important crop with an economic value in the tens of billions of dollars, and a significant supplier of essential vitamins, minerals, and phytochemicals in the human diet. Shelf life is a key quality trait related to alterations in cuticle properties and remodeling of the fruit cell walls. Studies with transgenic tomato plants undertaken over the last 20 years have indicated that a range of pectin-degrading enzymes are involved in cell wall remodeling. These studies usually involved silencing of only a single gene and it has proved difficult to compare the effects of silencing these genes across the different experimental systems. Here we report the generation of CRISPR-based mutants in the ripening-related genes encoding the pectin-degrading enzymes pectate lyase (PL), polygalacturonase 2a (PG2a), and β-galactanase (TBG4). Comparison of the physiochemical properties of the fruits from a range of PL , PG2a , and TBG4 CRISPR lines demonstrated that only mutations in PL resulted in firmer fruits, although mutations in PG2a and TBG4 influenced fruit color and weight. Pectin localization, distribution, and solubility in the pericarp cells of the CRISPR mutant fruits were investigated using the monoclonal antibody probes LM19 to deesterified homogalacturonan, INRA-RU1 to rhamnogalacturonan I, LM5 to β-1,4-galactan, and LM6 to arabinan epitopes, respectively. The data indicate that PL, PG2a, and TBG4 act on separate cell wall domains and the importance of cellulose microfibril-associated pectin is reflected in its increased occurrence in the different mutant lines., (© 2019 American Society of Plant Biologists. All Rights Reserved.)

Cassava ( Manihot esculenta Crantz) is the predominant staple food in Sub-Saharan Africa (SSA) and an industrial crop in South East Asia. Despite focused breeding efforts for increased yield, resistance, and nutritional value, cassava breeding has not advanced at the same rapidity as other staple crops. In the present study, metabolomic techniques were implemented to characterize the chemotypes of selected cassava accessions and assess potential resources for the breeding program. The metabolite data analyzed was applied to describe the biochemical diversity available in the panel, identifying South American accessions as the most diverse. Genotypes with distinct phenotypic traits showed a representative metabolite profile and could be clearly identified, even if the phenotypic trait was a root characteristic, e.g., high amylose content.

Carotenoids are important antioxidant components in the human diet. To develop carotenoid-rich agricultural products by genetic intervention, understanding the genetic basis of carotenoids variation is essential. In this study, we constructed a high-density integrated genetic map with 3817 molecular markers using specific locus amplified fragment (SLAF) sequencing from a C. reticulata × P. trifoliata F 1 pseudotestcross population. A total of 17 significant quantitative trait loci (QTLs) distributed on Chromosomes (Chr) 2, 3, 5, 6, and 9 were detected to determine the carotenoid variation in the population. In particular, three QTL colocalizations for multiple carotenoid constituents were observed on Chr 2, 3, and 9, one of which was located on Chr2:34,654,608-35430715 accounted for 20.1-25.4% of the variation of luteoxanthin, auroxanthin, lutein, violaxanthin, and total carotenoid content. Overall, this study provides a genetic foundation for marker-assisted selection (MAS) breeding of nutritionally enhanced citrus fruit.

Main Conclusion: Diflufenican increased 493-fold the level of phytoene. Diflufenican-induced inhibition of phytoene desaturase gene expression in carrot cells resulted in an increased production of phytoene. This work analyzes the effect of diflufenican, an inhibitor of phytoene desaturase, on the gene expression profiles of the biosynthetic pathway of carotenoids related with the production of these compounds in carrot cell cultures. The results showed that the presence of 10 µM diflufenican in the culture medium increased phytoene levels, which was 493-fold higher than in control cells after 7 days of treatment but did not alter cell growth in carrot cell cultures. The maximal production of phytoene was reached with 10 µM diflufenican after 7 days of incubation in the presence of light and with 30 g/L sucrose in the culture medium. Moreover, diflufenican decreased the expression of phytoene synthase and phytoene desaturase genes at all the times studied. This diflufenican-induced inhibition of phytoene desaturase gene expression in carrot cell cultures resulted in an increased production of phytoene. Our results provide new insights into the action of diflufenican in carrot cell cultures, which could represent an alternative more sustainable and environmentally friendly system to produce phytoene than those currently used.

Astaxanthin from a transgenic maize line was evaluated as feed supplement source conferring effective pigmentation of rainbow trout flesh. An extraction procedure using ethanol together with the addition of vegetal oil was established. This resulted in an oily astaxanthin preparation which was not sufficiently concentrated for direct application to the feed. Therefore, a concentration process involving multiple phase partitioning steps was implemented to remove 90 % of the oil. The resulting astaxanthin raw material contained non-esterified astaxanthin with 12 % 4-keto zeaxanthin and 2 % zeaxanthin as additional carotenoids. Isomeric analysis confirmed the exclusive presence of the 3S, 3'S astaxanthin enantiomer. The geometrical isomers were 89 % all-E, 8 % 13-Z and 3 % 9-Z. The incorporation of the oily astaxanthin preparation into trout feed was performed to deliver 7 mg/kg astaxanthin in the final feed formulation for the first 3.5 weeks and 72 mg/kg for the final 3.5 weeks of the feeding trial. The resulting pigmentation of the trout fillets was determined by hue values with a colour meter and further confirmed by astaxanthin quantification. Pigmentation properties of the maize-produced natural astaxanthin incorporated to 3.5 µg/g dw in the trout fillet resembles that of chemically synthesized astaxanthin. By comparing the relative carotenoid compositions in feed, flesh and feces, a preferential uptake of zeaxanthin and 4-keto zeaxanthin over astaxanthin was observed.

Maize was genetically engineered for the biosynthesis of the high value carotenoid astaxanthin in the kernel endosperm. Introduction of a β-carotene hydroxylase and a β-carotene ketolase into a white maize genetic background extended the carotenoid pathway to astaxanthin. Simultaneously, phytoene synthase, the controlling enzyme of carotenogenesis, was over-expressed for enhanced carotenoid production and lycopene ε-cyclase was knocked-down to direct more precursors into the β-branch of the extended ketocarotenoid pathway which ends with astaxanthin. This astaxanthin-accumulating transgenic line was crossed into a high oil- maize genotype in order to increase the storage capacity for lipophilic astaxanthin. The high oil astaxanthin hybrid was compared to its astaxanthin producing parent. We report an in depth metabolomic and proteomic analysis which revealed major up- or down- regulation of genes involved in primary metabolism. Specifically, amino acid biosynthesis and the citric acid cycle which compete with the synthesis or utilization of pyruvate and glyceraldehyde 3-phosphate, the precursors for carotenogenesis, were down-regulated. Nevertheless, principal component analysis demonstrated that this compositional change is within the range of the two wild type parents used to generate the high oil producing astaxanthin hybrid.

Carotenoids represent some of the most important secondary metabolites in the human diet, and tomato (Solanum lycopersicum) is a rich source of these health-promoting compounds. In this work, a novel and fruit-related regulator of pigment accumulation in tomato has been identified by artificial neural network inference analysis and its function validated in transgenic plants. A tomato fruit gene regulatory network was generated using artificial neural network inference analysis and transcription factor gene expression profiles derived from fruits sampled at various points during development and ripening. One of the transcription factor gene expression profiles with a sequence related to an Arabidopsis (Arabidopsis thaliana) ARABIDOPSIS PSEUDO RESPONSE REGULATOR2-LIKE gene (APRR2-Like) was up-regulated at the breaker stage in wild-type tomato fruits and, when overexpressed in transgenic lines, increased plastid number, area, and pigment content, enhancing the levels of chlorophyll in immature unripe fruits and carotenoids in red ripe fruits. Analysis of the transcriptome of transgenic lines overexpressing the tomato APPR2-Like gene revealed up-regulation of several ripening-related genes in the overexpression lines, providing a link between the expression of this tomato gene and the ripening process. A putative ortholog of the tomato APPR2-Like gene in sweet pepper (Capsicum annuum) was associated with pigment accumulation in fruit tissues. We conclude that the function of this gene is conserved across taxa and that it encodes a protein that has an important role in ripening.

In a red bacterial strain SF238 belonging to Sporosarcina aquimarina, a C(30) carotenoid biosynthetic pathway was identified. It has been reconstructed by analysis of intermediates that accumulate in two different pigment mutants. It starts with the synthesis of 4,4'-diapophytoene and proceeds with its desaturation to 4,4'-diapolycopene, which is then oxidized to 4,4'-diapolycopene-4,4'-dioate. Using a combination of HPLC-PDA and LC-MS/MS analyses, the final product of this pathway was identified as acetyl-4,4'-diapolycopene-4,4'-dioate. This is a novel carotenoid not reported in any organisms to date. It could be demonstrated that this carotenoid has excellent antioxidative properties to protect from photosensitized peroxidation reactions like other related 4,4'-diapolycopene-4,4'-dioate derivatives.

Numerous carotenoid-producing Gram positive bacteria have now been identified. Their carotenoid profiles are typically complex with C(30) diapocarotenoid skeletons being modified by glucosidation and esterification. In the present article the protocols necessary to identify and quantify these diapocarotenoids are described. Bacillus species capable of forming spores will be used as generic examples and the associated procedures will cover the cultivation of the bacteria, extraction, chromatographic separations, and online detection by Photo Diode Array (PDA) and Mass Spectrometry (MS).

Planococcus maritimus strain iso-3 was isolated from an intertidal sediment sample from the Clyde estuary in the UK. A novel red pigment glyco-carotenoic acid ester, methyl glucosyl-3,4-dehydro-apo-8'-lycopenoate has been isolated from this marine bacterium using chromatographic methods. The structure of methyl glucosyl-3,4-dehydro-apo-8'-lycopenoate was determined to be methyl 1-(beta-D-glucopyranosyloxy)-3,4-didehydro-1,2-dihydro-8'-apo-psi-caroten-8'-oate by the degradation experiment and the spectroscopic analyses. The methyl glucosyl-3,4-dehydro-apo-8'-lycopenoate showed potent antioxidative activity in the (1)O(2) suppression model.

Epidemiological studies show that dietary products rich in carotenoids delay the progression of age-related macular degeneration. Experimental evidence from cellular studies on the antioxidant actions of carotenoids in the retinal pigment epithelium is still, however, fragmentary. The present study examined the uptake and protective potential of dietary carotenoids from tomato on the human retinal pigment epithelial cell line ARPE-19. ARPE-19 cells were incubated in medium supplemented with tomato extract containing high levels of beta-carotene, lycopene and traces of lutein. The cellular uptake of carotenoids was analysed by reverse-phase HPLC. Oxidative stress was induced by treatment with 1 mm-H2O2. Nitrotyrosine was detected by immunocytochemistry, and oxidised proteins (protein carbonyls) were measured by a quantitative ELISA method. Lipid peroxidation was assessed by quantifying thiobarbituric acid reactive substances. ARPE-19 cells preferentially accumulated lutein and beta-carotene rather than lycopene. Nitrotyrosine formation was considerably reduced in cells incubated with tomato extract compared with controls after H2O2 treatment. Protein carbonyls were reduced by 30 % (P = 0.015), and the formation of thiobarbituric acid-reactive substances was reduced by 140 % (P = 0.003) in cells incubated with tomato extract. The present study provides the experimental evidence for protective effects of dietary tomatoes rich in carotenoids on oxidative stress in the retinal pigment epithelium.