Fruit Pericarp Research Articles

Chemical and thermal characteristics of soluble polysaccharides from fruit pericarps of the Algerian Argania spinosa

Abstract Soluble polysaccharides were isolated from fruit pericarps of the Algerian Argania spinosa. The cell wall fraction was subjected to sequential extractions with H2O (2 × 2 h at 100°C), EDTA (1%, 6 h at 80°C) and KOH (1 and 4 M, 14 h at 25°C). The structures of the obtained polysaccharide fractions were characterized using gas chromatography (GC), infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The presence of arabinose, galactose and rhamnose in the pectin fractions suggests the presence of rhamnogalacturonan, while the abundance of xylose in the hemicellulosic fractions indicates the presence of xylan. The DSC data revealed the endothermal behavior of all the soluble polysaccharides and only two thermal transitions, the glass transition (Tg) and the fusion transition (Tf) have been recorded.

Dynamics of mineral nutrients in tomato (Solanum lycopersicum L.) fruits during ripening: part I—on the plant

Tomato (Solanum lycopersicum L.) fruits of nine popular varieties in India were analysed for change in the levels of different nutrients (P, K, Fe, Zn, B, Cu, Mg, Ca and Mn) during the period of their postharvest ripening (fruits harvested at green mature stage and stored at 25 ± 1 °C). This work is in continuation of our previous and related work wherein similar studies were done on the tomato fruits undergoing ripening while attached to the plant (Ramesh in 1–15, 2020). Here in this study, nutrients were estimated in the outer pericarp of tomato fruits at the time of their harvest (at green mature stage) and during the storage period at 5, 10 and 14 days after harvest (DAH). Under above said storage conditions, ripening behaviour of tomato fruits of different varieties was also determined by ripening index (RI %) at 3, 5, 8, 10 and 14 DAH. The results on nutrients showed net increase in P, K, Fe, Zn, B and Cu with static levels for Mg, Ca, and Mn at 14 DAH in comparison to their levels at green mature stage. The increase is explained in view of remobilization of nutrients from other parts of the fruit to the outer pericarp. While, internal mobilization of nutrients within the fruit might have helped in maintaining the static level of nutrients. Correlation analyses revealed that lower content of K and Ca along with higher content of B and Cu can impart slow ripening to tomato fruits. Comparison between plant-attached (our earlier study) and plant-detached tomato fruits (this study) indicated that in contrast to the fruits at green mature stage there is net increase in Zn, B, Cu, Mg, Ca and Mn in the outer pericarp of plant-detached ripened fruits. This was due to the internal mobilization of nutrients within the fruits towards the outer pericarp and absence of any remobilization or back flow of nutrients away from the fruits as the fruits were off the plant.

Structural and functional features of phytoene synthase isoforms PSY1 and PSY2 in pepper Capsicum annuum L. cultivars.

The fruits of various pepper cultivars are characterized by a different color, which is determined by the pigment ratio; carotenoids dominate in ripe fruits, while chlorophylls, in immature fruits. A key regulator of carotenoid biosynthesis is the phytoene synthase encoded by the PSY gene. The Capsicum annuum genome contains two isoforms of this enzyme, localized in leaf (PSY2) and fruit (PSY1) plastids. In this work, the complete PSY1 and PSY2 genes were identified in nine C. annuum cultivars, which differ in ripe fruit color. PSY1 and PSY2 sequence variability was 2.43 % (69 SNPs) and 1.21 % (36 SNPs). The most variable were PSY1 proteins of the cultivars ‘Maria’ (red-fruited) and ‘Sladkij shokolad’ (red-brown-fruited). All identified PSY1 and PSY2 homologs contained the phytoene synthase domain HH-IPPS and the transit peptide. In the PSY1 and PSY2 HH-IPPS domains, functionally significant sites were determined. For all accessions studied, the active sites (YAKTF and RAYV), aspartate-rich substrate-Mg2+-binding sites (DELVD and DVGED), and other functional residues were shown to be conserved. Transit peptides were more variable, and their similarity in the PSY1 and PSY2 proteins did not exceed 78.68 %. According to the biochemical data obtained, the largest amounts of chlorophylls and carotenoids across the cultivars studied were detected in immature and ripe fruits of the cv. ‘Sladkij shokolad’ and ‘Shokoladnyj’. Also, ripe fruits of the cv. ‘Nesozrevayuschij’ (green-fruited) were marked by significant chlorophyll content, but a minimum of carotenoids. The PSY1 and PSY2 expression patterns were determined in the fruit pericarp at three ripening stages in ‘Zheltyj buket’, ‘Sladkij shokolad’, ‘Karmin’ and ‘Nesozrevayuschij’, which have different ripe fruit colors: yellow, red-brown, dark red and green, respectively. In the leaves of the cultivars studied, PSY1 expression levels varied significantly. All cultivars were characterized by increased PSY1 transcription as the fruit ripened; the maximum transcription level was found in the ripe fruit of ‘Sladkij shokolad’, and the lowest, in ‘Nesozrevayuschij’. PSY2 transcripts were detected not only in the leaves and immature fruits, but also in ripe fruits. Assessment of a possible correlation of PSY1 and PSY2 transcription with carotenoid and chlorophyll content revealed a direct relationship between PSY1 expression level and carotenoid pigmentation during fruit ripening. It has been suggested that the absence of a typical pericarp pigmentation pattern in ‘Nesozrevayuschij’ may be associated with impaired chromoplast formation.

The effect of the blue light on the pericarp cell growth and lycopene content of cherry tomato (Solanum lycopersicum var. cerasiforme) fruit

The cherry tomato fruit size depends on the growth of the pericarp which is parenchymal cells. The blue light stimulates the expansion of cotyledon cells, hypocotyl cells and leaf cells. In this study, the cherry tomato fruit was used as a material to investigate the effects of the blue light on the pericarp cells growth in fruit growth stage and lycopene accumulation in fruit growth and ripening stage. After 7 days of the blue light (440, 450 or 460 nm) treatment, pericarp cells growth and physiological, biochemical changes of the pericarp cells of 7-day-old fruit pericarp piece in vitro were analyzed. The lycopene content and some organic compound contents of 42-day-old postharvest fruits treated by the blue light similarly in 7 days and 7, 21-day-old fruit wrapped with blue filter (440-510 nm filtered) in 7 days were measured. The results showed that the 450 nm wavelength blue light the increased pericarp thickness of 7-day-old fruits through the increasement of the pericarp cell diameter. The 460 nm wavelength blue light the increased lycopene content of 42-day-old postharvest fruits. The blue filter treatment increased the sugar total content of 7- day-old fruits and increased the lycopene content of 21-day-old fruits.

Evaluation of Cholinesterase Inhibitory Potential of Different Genotypes of Ziziphus nummularia, Their HPLC-UV, and Molecular Docking Analysis.

Ziziphus nummularia is an important source of valuable phytoconstituents, which are widely used in traditional medicine system of Indo-Pak sub-continent. In this study we investigated the distribution of phenolic compounds in the fruit pericarps of six different genotypes (ZNP01-06) of Z. nummularia growing in the unexplored hilly areas of Pakistan. The methanolic extracts of these genotypes were screened for total phenolic content (TPC), total flavonoid content (TFC), antioxidant, and cholinesterase inhibitory potentials. The observed biological potentials were explained in terms of the outcome of molecular docking and HPLC analyses. Among them, genotype ZNP02 displayed high TPC (88.50 ± 1.23 μg/mL) and showed potent scavenging activity against DPPH (67.03 ± 1.04 μg/mL) and ABTS (65.3 ± 1.74 μg/mL) in comparison to ascorbic acid (68.7 ± 0.47 μg/mL). Moreover, genotypes ZNP01, ZNP02, and ZNP04 displayed potent inhibition against acetyl and butyryl cholinesterases (AChE and BChE) with IC50 values of 21.2, 20.5, and 23.7 μg/mL (AChE) and 22.7, 24.4, and 33.1 μg/mL (BChE), respectively. Furthermore, the individual compounds in the most potent species ZNP01 responsible for potent enzyme inhibition (identified through HPLC-UV analysis), were computed via docking simulation software to the enzyme structures. Among these compounds rutin exhibited significant binding affinity with value of −9.20 kcal/mol. The differences amongst the phytochemical compositions of the selected genotypes highlighted the genotypic variations in them. Based on our results it was concluded that the selected plant can be used as remedy of oxidative stress and neurodegenerative diseases. However, further studies are needed to isolate responsible compounds and test the observed potential in vivo, along with toxicological evaluations in animal models.

The conserved brassinosteroid-related transcription factor BIM1a negatively regulates fruit growth in tomato.

Brassinosteroids (BRs) are steroid hormones that play key roles in plant development and defense. Our goal is to harness the extensive knowledge of the Arabidopsis BR signaling network to improve productivity in crop species. This first requires identifying components of the conserved network and their function in the target species. Here, we investigated the function of SlBIM1a, the closest tomato homolog of AtBIM1, which is highly expressed in fruit. SlBIM1a-overexpressing lines displayed severe plant and fruit dwarfism, and histological characterization of different transgenic lines revealed that SlBIM1a expression negatively correlated with fruit pericarp cell size, resulting in fruit size modifications. These growth phenotypes were in contrast to those found in Arabidopsis, and this was confirmed by the reciprocal ectopic expression of SlBIM1a/b in Arabidopsis and of AtBIM1 in tomato. These results determined that BIM1 function depends more on the recipient species than on its primary sequence. Yeast two-hybrid interaction studies and transcriptomic analyses of SlBIM1a-overexpressing fruit further suggested that SlBIM1a acts through its interaction with SlBZH1 to govern the transcriptional regulation of growth-related BR target genes. Together, these results suggest that SlBIM1a is a negative regulator of pericarp cell expansion, possibly at the crossroads with auxin and light signaling.

Analysis of natural colourant extracted from the pericarp of passion fruit

The pericarp of passion fruit is typically discarded before consumption. We aimed to demonstrate that pigments extracted from the pericarp could be used as natural colourants. We focused on the stability of the dyes in response to heat, light, and storage, which is the most pressing problem associated with natural colourants. The stability of the pigment in solutions was affected by certain factors. However, colour measurements confirmed that for test samples in powder form or those covered by a coloured commercial plastic bag or light shield, the pigments remain stable with no noticeable colour change. The pigment extracted from the pericarp included anthocyanins such as cyanidin-3-glucoside, peonidin-3-glucoside, callistephin, and cyanidin-3-rutinoside, which have 3-O-glycoside bonding of the C-ring. They were not found in the passion fruit pulp or seeds. The colour value of the pigment was lower than that of the same amount of red cabbage dye or purple sweet potato dye, which are typically used in food manufacturing. The pigment extracted from passion fruit pericarp was used to dye processed food such as jelly, which was coloured pink to red depending on the amount of pigment used. The passion fruit pericarp could be used as a low-cost natural red colourant.

Selection of Habanero Pepper F1 Hybrids (Capsicum chinense Jacq.) at the Yucatan Peninsula, Mexico with a High Potential for Different Markets

This study evaluated 29 F1 lines and the 11 genotypes of habanero peppers used in the crossbreeding program developed by the Scientific Research Center of Yucatan, México. A randomized complete block design with four repetitions was used. Eight plants of each of the genotypes were studied per block. A total of 22 qualitative and 18 quantitative descriptors established in the manuals of the International Plant Genetic Resources Institute (IPGRI) and the National Service for Seed Inspection and Certification (SNICS) was used. The multiple correspondence analysis of the qualitative traits explained 38.2% of the total variability. The trait that contributed the most to the qualitative variability identified was the presence of anthocyanins in the node. Principal component analysis showed that the first two axes explained 85.1% of the total variability and that capsaicin content and fruit pericarp thickness were the major contributors to the variation recorded. Based on these results, four F1 hybrids of habanero pepper were selected because of their promising traits for the different markets, i.e., high productive potential and/or high pungency. These traits are described in the section on Results.

Comparative carpology of the genus Cardiocrinum (Endl.) Lindl. (Liliaceae)

The anatomy of pericarp of the mature fruit of Cardiocrinum cordatum (Thunb.) Makino was investigated.It was revealed, that the fruit of Cardiocrinum is a superior loculicidal capsule. The anatomy of its pericarp allow totreat the fruit as a transitional type of capsules between Lilium-type (the endocarp is lignified) and Galanthus-type (nolignification occurs in any zone of the pericarp). The peculiarities of pricarp structure of Cardiocrinum supports itstreatmend as a separate genus of the Liliaceae family.

Investigation of the antimicrobial effects of Sapindus mukorossi on endodontic pathogens

Endodontic infections have a polymicrobial nature. Thus, eliminating the microorganisms from infected root canals without damaging healthy surrounding tissue is a major concern. Sapindus mukorossi (S. mukorossi) is a natural product with potential antimicrobial effects. The aim of this study was to evaluate whether various extract solutions of S. mukorossi have an antimicrobial activity against specific endodontic pathogens. Extracts were obtained from S. mukorossi fruit pericarps using methanol, ethanol, butanol and distilled water solvents. The inhibition zone, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and minimum fungicidal concentration (MFC) were determined with disc diffusion assay, broth microdilution assay and agar dilution assay. Antimicrobial inhibitory activity was observed with all four different solvent extracts of S. mukorossi against Fusobacterium nucleatum American Type Culture Collection (ATCC) 25586, Porphyromonas gingivalis ATCC 33277 and Actinomyces odontolyticus (clinical isolate). The MIC values were ranged 10.24-10.24, 0.01-0.64 and 1.28- 2.56 mg/mL, respectively. The MBC value was not detected for Fusobacterium nucleatum ATCC 25586. The MBC values were 0.02-1.25 and 2.56-5.12 mg/ mL for Porphyromonas gingivalis ATCC 33277 and Actinomyces odontolyticus (clinical isolate), respectively. Antifungal activities were also observed with the four different solvent extracts of S. mukorossi against Candida albicans ATCC 10231 and C. albicans clinical isolates 1, 2 and 3. The inhibition zone diameter values were in the range of 18-21 mm. The MIC values for C. albicans ATCC 10231 and C. albicans clinical isolates 1, 2 and 3 were 0.2-0.4 and MFC values were 0.4-0.8 mg/mL, respectively. The antimicrobial effects of the S. mukorossi fruit pericarp extract inhibited the growth of P. gingivalis, A. odontolyticus, F. nucleatum, and especially the C. albicans strains. S. mukorossi extract has interesting potential as an antimicrobial agent against endodontic pathogens.

Effect of Environmental Conditions on the Yield of Peel and Composition of Essential Oils from Citrus Cultivated in Bahia (Brazil) and Corsica (France)

The cosmetic and fragrance industry largely exploits citrus essential oils (EOs) because of their aromatic properties. EO compositions are complex and differ between fruit pericarp (PEO) and leaf (LEO). Citrus fruit grow in many countries under very different climates. Seventeen citrus cultivars were selected and their similarities between the two collections were verified by SSR (Single Sequence Repeat) and InDel (Insertion and Deletion) markers to assess the effects of the environment and cultivation practices on the EO yield and composition. LEOs and PEOs were extracted by water distillation and analyzed by GC-MS. PEO yields were generally higher in Corsica than in Bahia, especially in the citron family. PEOs in this family were richer in limonene in Bahia than in Corsica while, conversely, neral, geranial and derivatives were present in a higher proportion in Corsican varieties. A few minor components were site-specific, such as nookaton, a pummelo-specific compound that was not present in grapefruit cultivated in Bahia. If climate change over the last 20 years has not affected the PEO composition in Corsica, the contrasted environmental conditions and cultural practices between Bahia and Corsica could possibly explain the EO variations.

The embryological insight into the relationship between Forsythia and Abeliophyllum (Forsythieae, Oleaceae).

Forsythia saxatilis, a Korean native Forsythia, is recognized as an endangered species in the Korean Red List. We carried out a comprehensive embryological investigation, including a study of the pericarp development, of F. saxatilis and compared it with previously acquired information on the family Oleaceae and also with Abeliophyllum distichum, a close relative of Forsythia. Our results revealed that several embryological features of Forsythia are exclusively comparable with the family Oleaceae, particularly in relation to A. distichum. Despite the differences in fruit types and pericarp ontogeny, Forsythia shares some unique embryological features with Abeliophyllum, for instance the basic type of anther wall development, formation of the nucellar cap, a long micropyle, formation of the obturator and hypostase, and the crushed endotesta. Furthermore, the loculicidal capsule of Forsythia seems to be primitive within the tribe Forsythieae and samara of Abeliophyllum might be evolved from it. In conclusion, a considerable number of synapomorphies of embryological characters supports recent molecular reports and provide additional embryological evidence for the sister-group relationship of Forsythia and Abeliophyllum.

Ripening-related cell wall modifications in olive (Olea europaea L.) fruit: A survey of nine genotypes

The production of olive (Olea europaea L.) is very important economically in many areas of the world, and particularly in countries around the Mediterranean basin. Ripening-associated modifications in cell wall composition and structure of fruits play an important role in attributes like firmness or susceptibility to infestations, rots and mechanical damage, but limited information on these aspects is currently available for olive. In this work, cell wall metabolism was studied in fruits from nine olive cultivars (‘Arbequina’, ‘Argudell’, ‘Empeltre’, ‘Farga’, ‘Manzanilla’, ‘Marfil’, ‘Morrut’, ‘Picual’ and ‘Sevillenca’) picked at three maturity stages (green, turning and ripe). Yields of alcohol-insoluble residue (AIR) recovered from fruits, as well as calcium content in fruit pericarp, decreased along ripening. Cultivar-specific diversity was observed in time-course change patterns of enzyme activity, particularly for those acting on arabinosyl- and galactosyl-rich pectin side chains. Even so, fruit firmness levels were associated to higher pectin methylesterase (PME) activity and calcium contents. In turn, fruit firmness correlated inversely with ascorbate content and with α-l-arabinofuranosidase (AFase) and β-galactosidase (β-Gal) activities, resulting in preferential loss of neutral sugars from cell wall polymers.

Balancing of hormonal biosynthesis and catabolism pathways, a strategy to ameliorate the negative effects of heat stress on reproductive growth.

In pea (Pisum sativum L.), moderate heat stress during early flowering/fruit set increased seed/ovule abortion, and concomitantly produced fruits with reduced ovary (pericarp) length, and fewer seeds at maturity. Plant hormonal networks coordinate seed and pericarp growth and development. To determine if these hormonal networks are modulated in response to heat stress, we analyzed the gene expression patterns and associated these patterns with precursors, and bioactive and inactive metabolites of the auxin, gibberellin (GA), abscisic acid (ABA), and ethylene biosynthesis/catabolism pathways in young developing seeds and pericarps of non-stressed and 4-day heat-stressed fruits. Our data suggest that within the developing seeds heat stress decreased bioactive GA levels reducing GA growth-related processes, and that increased ethylene levels may have promoted this inhibitory response. In contrast, heat stress increased auxin biosynthesis gene expression and auxin levels in the seeds and pericarps, and seed ABA levels, both effects can increase seed sink strength. We hypothesize that seeds with higher auxin- and ABA-induced sink strength and adequate bioactive GA levels will set and continue to grow, while the seeds with lower sink strength (low auxin, ABA, and GA levels) will become more sensitive to heat stress-induced ethylene leading to ovule/seed abortion.

Effects of hydrogen water treatment on antioxidant system of litchi fruit during the pericarp browning

Litchi fruit were exposed to 0.7 PPM hydrogen water (HW) before storage at 25 ± 1 ℃. HW treatment delayed the pericarp browning and maintained the total soluble solids (TSS) of litchi fruit. Then, a total of 25 antioxidant system-related characters were determined to evaluate the effects of HW on antioxidant system during pericarp browning. Compared with control pericarp, the pericarp of HW-treated litchi fruit exhibited higher levels of superoxide radical (O2−·) scavenging activity, glutathione (GSH), monodehydroascorbate reductase (MDHAR), polyphenol oxidase (PPO) and total flavonoids during whole storage, higher levels of hydrogen peroxide (H2O2), catalase (CAT), glutathione disulfide (GSSG), ascorbate oxidase (AAO) and total phenols only on day 1, and higher levels of ascorbate peroxidase (APX), total anthocyanin, glutathione reductase (GR) and glutathione peroxidases (GPX) at later stage of storage. Those HW-induced antioxidant system-related characters might directly or indirectly enhanced the antioxidant capacity and delayed the pericarp browning of litchi.

Uncovering Candidate Genes Controlling Major Fruit-Related Traits in Pepper via Genotype-by-Sequencing Based QTL Mapping and Genome-Wide Association Study.

All modern pepper accessions are products of the domestication of wild Capsicum species. However, due to the limited availability of genome-wide association study (GWAS) data and selection signatures for various traits, domestication-related genes have not been identified in pepper. Here, to address this problem, we obtained data for major fruit-related domestication traits (fruit length, width, weight, pericarp thickness, and fruit position) using a highly diverse panel of 351 pepper accessions representing the worldwide Capsicum germplasm. Using a genotype-by-sequencing (GBS) method, we developed 187,966 genome-wide high-quality SNP markers across 230 C. annuum accessions. Linkage disequilibrium (LD) analysis revealed that the average length of the LD blocks was 149 kb. Using GWAS, we identified 111 genes that were linked to 64 significant LD blocks. We cross-validated the GWAS results using 17 fruit-related QTLs and identified 16 causal genes thought to be associated with fruit morphology-related domestication traits, with molecular functions such as cell division and expansion. The significant LD blocks and candidate genes identified in this study provide unique molecular footprints for deciphering the domestication history of Capsicum. Further functional validation of these candidate genes should accelerate the cloning of genes for major fruit-related traits in pepper.

Transcriptome and Hormone Analyses Revealed Insights into Hormonal and Vesicle Trafficking Regulation among Olea europaea Fruit Tissues in Late Development.

Fruit ripening and abscission are the results of the cell wall modification concerning different components of the signaling network. However, molecular-genetic information on the cross-talk between ripe fruit and their abscission zone (AZ) remains limited. In this study, we investigated transcriptional and hormonal changes in olive (Olea europaea L. cv Picual) pericarp and AZ tissues of fruit at the last stage of ripening, when fruit abscission occurs, to establish distinct tissue-specific expression patterns related to cell-wall modification, plant-hormone, and vesicle trafficking in combination with data on hormonal content. In this case, transcriptome profiling reveals that gene encoding members of the α-galactosidase and β-hexosaminidase families associated with up-regulation of RabB, RabD, and RabH classes of Rab-GTPases were exclusively transcribed in ripe fruit enriched in ABA, whereas genes of the arabinogalactan protein, laccase, lyase, endo-β-mannanase, ramnose synthase, and xyloglucan endotransglucosylase/hydrolase families associated with up-regulation of RabC, RabE, and RabG classes of Rab-GTPases were exclusively transcribed in AZ-enriched mainly in JA, which provide the first insights into the functional divergences among these protein families. The enrichment of these protein families in different tissues in combination with data on transcript abundance offer a tenable set of key genes of the regulatory network between olive fruit tissues in late development.

Assessment of genetic variability, heritability and genetic advance in Tomato

Genetic variability studies provide the basic information on genetic properties of the population based on which breeding methods could be formulated for further improvement of the crop. Hence the variability, heritability and genetic advance were studied for fruit yield and its 14 component traits in 40 advance lines of tomato at Regional Research Station, Semiliguda, Koraput during kharif season, 2017. The results showed significant differences indicating the presence of high genetic variability among the genotypes. PCV and GCV were high for total chlorophyll content, total fruit yield and root volume. High degree of heritability estimates were obtained in case of total chlorophyll content, total fruit yield, root volume, pericarp thickness, plant height and number of fruits per plant. Genetic advance was highest for total chlorophyll content, number of fruit per plant and total fruit yield. Therefore, total chlorophyll content and number of fruits were the important components and could be utilized for achieving maximum fruit yield.

Fruit of Staphylea (Staphyleaceae) from the Oligocene of Montana, USA

Staphylea has abundant isolated seeds in the fossil record, but no fossil fruits of this genus have been confirmed before. In this paper, we report a capsular fruit of Staphylea from the Oligocene Renova Formation of Woodworth, western-central Montana, USA. Detailed investigation of this fruit gives new insights on the phylogenetic and biogeographic history of the genus. Morphological comparison with modern Staphylea fruits shows its closest resemblance to the extant Asian species, S. bumalda DC., which is similar in fruit shape, size, and pericarp venation, but differs by the angle of interlobal sinus and the stipe development. We establish a new fossil species, S. woodworthensis Zhu & Manchester sp. nov. for this fossil fruit. This discovery indicates that Staphylea was already established in western North America at least by the Oligocene, which is inconsistent with the recent interpretation of a late Oligocene origin of the genus in Europe. The distribution of fossils indicates an earlier diversification of Staphylea, along with other staphyleaceous genera, back to early Paleogene in North America. The genus subsequently retracted its range to the east and south in North America as evidenced by younger fossils and its modern geographic range.

Modulation of the Tomato Fruit Metabolome by LED Light.

Metabolic profiles of tomatoes change during ripening and light can modulate the activity of relevant biochemical pathways. We investigated the effects of light directly supplied to the fruits on the metabolome of the fruit pericarp during ripening. Mature green tomatoes were exposed to well-controlled conditions with light as the only varying factor; control fruits were kept in darkness. In experiment 1 the fruits were exposed to either white light or darkness for 15 days. In experiment 2, fruits were exposed to different light spectra (blue, green, red, far-red, white) added to white background light for seven days. Changes in the global metabolome of the fruit pericarp were monitored using LCMS and GCMS (554 compounds in total). Health-beneficial compounds (carotenoids, flavonoids, tocopherols and phenolic acids) accumulated faster under white light compared to darkness, while alkaloids and chlorophylls decreased faster. Light also changed the levels of taste-related metabolites including glutamate and malate. The light spectrum treatments indicated that the addition of blue light was the most effective treatment in altering the fruit metabolome. We conclude that light during ripening of tomatoes can have various effects on the metabolome and may help with shaping the levels of key compounds involved in various fruit quality characteristics.