Carotenoid Content Of Fruits Research Articles

Integrative Analysis of Metabolome and Transcriptome of Carotenoid Biosynthesis Reveals the Mechanism of Fruit Color Change in Tomato (Solanum lycopersicum).

Tomato fruit ripening is accompanied by carotenoid accumulation and color changes. To elucidate the regulatory mechanisms underlying carotenoid synthesis during fruit ripening, a combined transcriptomic and metabolomic analysis was conducted on red-fruited tomato (WP190) and orange-fruited tomato (ZH108). A total of twenty-nine (29) different carotenoid compounds were identified in tomato fruits at six different stages. The abundance of the majority of the carotenoids was enhanced significantly with fruit ripening, with higher levels of lycopene; (E/Z)-lycopene; and α-, β- and γ-carotenoids detected in the fruits of WP190 at 50 and 60 days post anthesis (DPA). Transcriptome analysis revealed that the fruits of two varieties exhibited the highest number of differentially expressed genes (DEGs) at 50 DPA, and a module of co-expressed genes related to the fruit carotenoid content was established by WGCNA. qRT-PCR analysis validated the transcriptome result with a significantly elevated transcript level of lycopene biosynthesis genes (including SlPSY2, SlZCIS, SlPDS, SlZDS and SlCRTSO2) observed in WP190 at 50 DPA in comparison to ZH108. In addition, during the ripening process, the expression of ethylene biosynthesis (SlACSs and SlACOs) and signaling (SlEIN3 and SlERF1) genes was also increased, and these mechanisms may regulate carotenoid accumulation and fruit ripening in tomato. Differential expression of several key genes in the fruit of two tomato varieties at different stages regulates the accumulation of carotenoids and leads to differences in color between the two varieties of tomato. The results of this study provide a comprehensive understanding of carotenoid accumulation and ethylene biosynthesis and signal transduction pathway regulatory mechanisms during tomato fruit development.

Study on carotenoid content in berry fruits

In addition to ascorbic acid and phenolic compounds, yellow, orange, and bright red fruit and berry crops contain carotenoids—antioxidant substances that have a positive effect on the human body. The article presents the results of studying the content of carotenoids in light-colored berry fruits: sea buckthorn, gooseberry, and red currant. Sea buckthorn was found to be the leader in the accumulation of this biologically active substance. In gooseberry and red currant, which have light-colored fruits, carotenoids are found in small amounts. The average carotenoid content is as follows: sea buckthorn – 4.98 ± 0.49 mg/100 g; gooseberry – 0.68 ± 0.07 mg/100 g; red currant – 0.33 ± 0.04 mg/100 g.The average content of carotenoids accumulated in sea buckthorn fruits varies significantly from 1.69 (Zheltoplodnaya) to 10.59 mg/100 g (ELS 8-51), with a variation interval of 8.90 mg/100 g and a variation coefficient of 46.0%. Of the studied varieties, elite and selected forms of sea buckthorn, specimens having a carotenoid content of over 6.00 mg/100 g in fruits were identified: Karamelka, Kenigsbergskaya, Podarok Chernozem’yu, Syurpriz Baltiki, ELS 8-51, and OS 8-51-44-20. In 31.8% of variety specimens, the carotenoid content in fruit was lower than the variety average (below 3.50 mg/100 g)– from 1.69 to 3.46 mg/100 g. Of breeding interest is the selected elite young plant 8-51 that accumulates the maximum amount of carotenoids in fruit (10.59 mg/100 g) and exhibits the studied trait stability (V = 10.9%). Gooseberry and red currant are of no breeding interest as sources of carotenoids.

A Lycopene ε-Cyclase TILLING Allele Enhances Lycopene and Carotenoid Content in Fruit and Improves Drought Stress Tolerance in Tomato Plants.

In the scenario of climate change, the availability of genetic resources for tomato cultivation that combine improved nutritional properties and more tolerance to water deficiency is highly desirable. Within this context, the molecular screenings of the Red Setter cultivar-based TILLING platform led to the isolation of a novel lycopene ε-cyclase gene (SlLCY-E) variant (G/3378/T) that produces modifications in the carotenoid content of tomato leaves and fruits. In leaf tissue, the novel G/3378/T SlLCY-E allele enhances β,β-xanthophyll content at the expense of lutein, which decreases, while in ripe tomato fruit the TILLING mutation induces a significant increase in lycopene and total carotenoid content. Under drought stress conditions, the G/3378/T SlLCY-E plants produce more abscisic acid (ABA) and still conserve their leaf carotenoid profile (reduction of lutein and increase in β,β-xanthophyll content). Furthermore, under said conditions, the mutant plants grow much better and are more tolerant to drought stress, as revealed by digital-based image analysis and in vivo monitoring of the OECT (Organic Electrochemical Transistor) sensor. Altogether, our data indicate that the novel TILLING SlLCY-E allelic variant is a valuable genetic resource that can be used for developing new tomato varieties, improved in drought stress tolerance and enriched in fruit lycopene and carotenoid content.

Elevating fruit carotenoid content in apple (Malus x domestica Borkh).

Carotenoid compounds accumulate to confer coloration to plant tissues and have some established health benefits in humans. These pigments have antioxidant properties and are precursors of vitamin A, which is important for human vision. Apple is widely consumed globally, but most commercial apple cultivars have low fruit carotenoid content because these pigments accumulate mostly in the fruit skin rather than the flesh (the majority of the edible portion). Although carotenoids accumulate in the early stages of fruit development, much of this carotenoid is lost by fruit maturity as a result of low biosynthetic rate, rapid turnover of compounds and/or lack of storage capacity in these tissues. Improving apple fruit carotenoid content through traditional breeding or genetic technologies, will take a long time because of the extended juvenile phase of the trees and limited germplasm diversity within many commercial breeding programs. This process, however, can be accelerated by fundamental understanding of the apple carotenoid biosynthetic pathway and the mechanisms controlling the metabolic steps. The availability of a well annotated apple genome sequence has led to the identification of apple carotenoid gene families and potential transcription factors. This is an important step since the knowledge could be used to elevate carotenoid content either through breeding or genetic transformation techniques. Here, we provide an overview of carotenogenesis in apple and outline the methods employed to improve the carotenoid content of this horticultural crop.

Daucus carota DcPSY2 and DcLCYB1 as Tools for Carotenoid Metabolic Engineering to Improve the Nutritional Value of Fruits.

Carotenoids are pigments with important nutritional value in the human diet. As antioxidant molecules, they act as scavengers of free radicals enhancing immunity and preventing cancer and cardiovascular diseases. Moreover, α-carotene and β-carotene, the main carotenoids of carrots (Daucus carota) are precursors of vitamin A, whose deficiency in the diet can trigger night blindness and macular degeneration. With the aim of increasing the carotenoid content in fruit flesh, three key genes of the carotenoid pathway, phytoene synthase (DcPSY2) and lycopene cyclase (DcLCYB1) from carrots, and carotene desaturase (XdCrtI) from the yeast Xanthophyllomyces dendrorhous, were optimized for expression in apple and cloned under the Solanum chilense (tomatillo) polygalacturonase (PG) fruit specific promoter. A biotechnological platform was generated and functionally tested by subcellular localization, and single, double and triple combinations were both stably transformed in tomatoes (Solanum lycopersicum var. Microtom) and transiently transformed in Fuji apple fruit flesh (Malus domestica). We demonstrated the functionality of the S. chilense PG promoter by directing the expression of the transgenes specifically to fruits. Transgenic tomato fruits expressing DcPSY2, DcLCYB1, and DcPSY2-XdCRTI, produced 1.34, 2.0, and 1.99-fold more total carotenoids than wild-type fruits, respectively. Furthermore, transgenic tomatoes expressing DcLCYB1, DcPSY2-XdCRTI, and DcPSY2-XdCRTI-DcLCYB1 exhibited an increment in β-carotene levels of 2.5, 3.0, and 2.57-fold in comparison with wild-type fruits, respectively. Additionally, Fuji apple flesh agroinfiltrated with DcPSY2 and DcLCYB1 constructs showed a significant increase of 2.75 and 3.11-fold in total carotenoids and 5.11 and 5.84-fold in β-carotene, respectively whereas the expression of DcPSY2-XdCRTI and DcPSY2-XdCRTI-DcLCYB1 generated lower, but significant changes in the carotenoid profile of infiltrated apple flesh. The results in apple demonstrate that DcPSY2 and DcLCYB1 are suitable biotechnological genes to increase the carotenoid content in fruits of species with reduced amounts of these pigments.

Effects of Conventional and Bokashi Hydroponics on Vegetative Growth, Yield and Quality Attributes of Bell Peppers.

Due to consumers’ awareness and concern about nutrition and health in different parts of the world, the adoption of organic hydroponics is increasing. This has led to a search for organic nutrient media. One of the viable nutrient sources for organic hydroponics is bokashi compost. The principal objective of this study was to compare the performance of 10% bokashi hydroponics with convention hydroponics for bell pepper production. The different hydroponics influenced vegetative growth parameters largely due to considerable differences in the mineral elements in both hydroponic systems. Stems of conventionally grown plants were significantly (p ≤ 0.05) thicker (10.2 mm) compared to those of the bokashi grown plants (7.3 mm). Conventionally grown plants had significantly (p ≤ 0.05) higher photosynthetic performance than bokashi grown plants; normalized difference vegetation index (NDVI) (78.80 versus 67.49), soil plant analysis development (SPAD; 73.89 versus 38.43), and quantum yield (QY; 0.64 versus 0.49). Leaf superoxide dismutase (SOD) activity in the leaves of bokashi grown plants (0.32 units/mg protein) was significantly (p ≤ 0.05) lower than in the leaves of conventionally grown plants (0.37 units/mg protein). This also corresponded to significantly (p ≤ 0.05) higher leaf sap content in the conventionally grown plant than bokashi grown plants. Furthermore, conventional hydroponics yielded three-fold greater pepper fruit per plant compared to bokashi. After 14 days of storage at 7 °C and 95% relative humidity, the firmness of both groups declined, especially for the bokashi grown fruit (27.73 shore unit), which was significantly lower compared to conventionally grown fruit (35.65 shore unit). However, there was an increase in carotenoid content in fruit grown in both hydroponic systems after storage. In conclusion, although bell pepper plant was successfully cultivated in bokashi hydroponics, the plant performance, fruit yield and postharvest quality were lower than conventional hydroponics. We believe that this study and its approach will provide future research with baseline information on optimizing media of bokashi hydroponics to produce bell pepper.

A novel gene, CaATHB-12, negatively regulates fruit carotenoid content under cold stress in Capsicum annuum.

BackgroundCarotenoids, the secondary metabolites terpenoids, are the largest factors that form the fruit color. Similar to flavonoids, they are not only safe and natural colorants of fruits but also play a role as stress response biomolecules.MethodsTo study the contribution of the key genes in carotenoids biosynthesis, fruit-color formation, and in response to cold stress, we characterized the key regulatory factor CaATHB-12 from the HD-ZIP I sub-gene family members in pepper.ResultsCold stress enhanced carotenoid accumulation as compared with the normal condition. CaATHB-12 silencing through virus-induced gene silencing changed the fruit color by regulating the carotenoid contents. CaATHB-12 silencing increased the antioxidant enzyme activities in the fruits of pepper, exposed to cold stress, whereas CaATHB-12 overexpression decreased the activities of antioxidant enzymes in the transgenic Arabidopsis lines, exposed to cold stress, suggesting that CaATHB-12 is involved in the regulation of cold stress in the pepper fruits.ConclusionOur research will provide insights into the formation of fruit color in pepper and contribution of CaATHB-12 in response to cold stress. Further study should be focused on the interaction between CaATHB-12 and its target gene.

Development of high-lycopene tomato hybrids using conventional breeding techniques and molecular markers

Relevance. High lycopene fruit content has been regarded as a very important genetic trait in tomato breeding. Use lycopene molecular markers in combination with conventional breeding techniques allowed us to create hybrids with high lycopene accumulation, excellent organoleptic qualities, high yield production and resistance to pathogens, and to effectively optimize our breeding programmes for commercial greehouses production.Material and Methods. In this study tomato samples including selected lines and hybrids with various allelic combinations of genes determining carotene accumulation, and other genetic traits, such as disease resistance and yield production were tested. Introgression of spontaneous and induced mutations was used to increase carotenoid levels (og and hp) and improve fruit technological qualities (nor, alc, rin). The research material was tomato collection, mutants, breeding lines and hybrids listed in the State Register Russian Federation tomato hybrids of breeding SS Agrofirm "Ilyinichna" VNIIO branch of the All-Russian Scientific Research Institute of Vegetable Growing – Branch of the FSBSI Federal Scientific Vegetable Center. DNA typing of fruit quality genes was performed at the Institute of Genetics and Cytology of the National Academy of Sciences of Belarus.Results. New domestic hybrids for industrial greenhouses, which characterised by improved organoleptic qualities and technological traits were developed with the help of phasedcross-breeding that allowed to combine the genes nor, rin, alc, leading to an extension of the shelf life with the genes B, og, hp1, etc., contributing to an increase in carotenoid content in fruits. It was established that for targeted selection and hybridization, despite the negative influence of the nor, rin, alc genes it is possible to raise the level of carotenoids to average values. Correlation between lycopene concentration in fruits and high temperature and level of insolation was confirmed. It was shown that pink-fruited forms contain significantly more lycopenethanred-fruitedones. Different all eliccombinations of structural genes involved in carotenoids biosynthesis and regulatory genes that provided maximal accumulation of lycopene in hybrid swithred and pink fruits were revealed. Hybrids with the combination of high concentrations of sugar (° Brix), dry matter and maximal lycopene values, combined defining excellent taste were selected: Prekrasnaiya lady, Olya, Quadrille, Victoria. New F1 hybrids one for industrial greenhouses: G950, G956, G960, Magistral and pink fruited G12897, surpassed the Dutch standard in productivity up to 21%, and in tastes/organoleptic qualities for 1-1.8 points.

Functional characterisation and in silico modelling of MdPSY2 variants and MdPSY5 phytoene synthases from Malus domestica

Carotenoids are plastid isoprenoid pigments that play critical roles in light harvesting, photoprotection, and phytohormone biosynthesis. They are also vitamin-A precursors and antioxidant molecules important for human nutrition. Apples (e.g. Malus x domestica Borkh), one of the most widely consumed fruits with high nutrient levels, have a very low carotenoid concentration in flesh, compared with other fruits and vegetables. This could be explained by a deficiency in carotenoid synthesis/accumulation and/or accelerated degradation. We analysed the contribution of M. domestica cv. ‘Fuji’ phytoene synthase (PSY) in the biosynthesis of carotenoids and determined that among four MdPSY genes present in the organism, MdPSY2 and MdPSY5 are highly expressed in leaves and during fruit ripening in line with an increment in carotenoid content in fruits. Furthermore, two representative polymorphic MdPSY2 variants were found, one with a Tyr358Phe substitution (MdPSY2_F) and the other that additionally has a six-amino-acid deletion in the signal peptide (MdPSY2_CG). MdPSY2, MdPSY5, MdPSY2_F and MdPSY2_CG are all localised in plastids. Interestingly, the polymorphic MdPSY2_F and MdPSY2_CG variants show lower enzymatic activity than the wild-type form in a heterologous complementation assay, which could be attributed to the Tyr358Phe substitution close to the active-site pocket, as was suggested by 3-D modelling analysis. The presence of polymorphic MdPSY2 variants with lower enzymatic activity could be partially responsible for the low carotenoid content in Fuji apple fruits.

Effects of In Vitro Polyploidization on Agronomic Characteristics and Fruit Carotenoid Content; Implications for Banana Genetic Improvement.

Bananas (Musa spp.), native to South East Asia, have spread worldwide and are integrated into the diets of millions of people in tropical regions. Carotenoid content varies dramatically between different banana genotypes, providing an opportunity for vitamin A biofortification. Polyploidization is a useful tool for crop improvement with potential to generate new diversity, especially in a polyploid crop like bananas. Ten induced tetraploids generated from six diploid banana genotypes were evaluated for their agronomic attributes and fruit carotenoid content in comparison to their diploid progenitors. Tetraploids had distinct plant morphology, but generally displayed inferior vegetative and yield characteristics with 20% lower bunch weights than their original diploids. Similarly, a 50% decrease in fruit provitamin A carotenoids (α-carotene, 13-cis β-carotene, 9-cis β-carotene, trans-β-carotene) accompanied by a corresponding increase in lutein was recorded in induced tetraploids in comparison to their original diploids. Additionally, all lines were subjected to pollen viability tests to assess their fertility. Pollen viability tests indicated over 70% viability for induced tetraploids and diploid controls, suggesting their possible use in crosses. These findings provide a basis for the application of induced polyploidization in bananas to generate useful genetic material for integration in hybridization programmes aiming to produce vitamin A enriched triploids valuable to malnourished populations.

THE INFLUENCE OF GENOTYPE AND STORAGE CONDITION ON THE CONTENT OF SELECTED BIOACTIVE SUBSTANCES IN THE FRUIT OF PUMPKIN (CUCURBITA MOSCHATA DUCH.)

Butternut squash (Cucurbita moschata) is a significant crop in terms of the content of bioactive substances with antioxidant properties – vitamin C, vitamin E, carotenoids, polyphenol compounds – as well as B-complex and potassium vitamins are appreciated by the consumer both raw and heat treated. It is suitable for storage, consumption in the fresh state or heat treatment thanks to its interesting sensory properties. The aim of the thesis was to evaluate the influence of genotype and storage conditions on the content of selected bioactive substances in the fruit of these six varieties: Liscia, Matilda F1, Orange, Serpentine, UG 205 F1 and Waltham F1. From bioactive substances we determined the content of total carotenoids and total polyphenols in the flesh of the fruits before and after storage. The total carotenoid content in the fruit before storage was in the range of 40.62 mg.100 g-1 DS (dry substance) to 76.78 mg.100 g-1 DS, after storage the range transformed into 50.58 mg.100 g -1 DS to up to 109.81 mg.100 g-1 DS. The total polyphenol content before storage ranged from 109.95 mg GAE.100 g-1 DS to 198.96 mg GAE.100 g-1 DS, after storage in the range of 152.51 mg of GAE.100 g-1 DS to 199.83 mg of GAE.100 g-1 DS. The results show that the highest content of total carotenoids in fresh fruits after harvest was determined in the pulp of the varieties UG 205 F1 (76.78 mg.100 g-1 DS), Orange (71.40 mg.100 g-1 DS), and high content of total polyphenols was determined in the Matilda F1 strains (198.96 mg GAE.100 g-1 DS) and Orange (166.09 mg GAE.100 g-1 DS). After two months of the fruit’s storage, the total carotenoid content significantly increased in Liscia by 91%, Orange and Waltham F1 both by 54%. The total polyphenol content considerably rose in Liscia and UG 205 F1 varieties by 39%. The highest content of total polyphenols after storage was found in Serpentine fruit (199.83 mg GAE.100 g-1 DS). It follows that from the point of view of the content of total carotenoids it makes sense to store the fruits of the Orange and Waltham F1 varieties and, in terms of total polyphenols content, the fruits of the Serpentine variety. Taking into account the development of the contents of both groups of bioactive substances, storage of the Liscia variety is recommended. The effect of genotype on total carotenoid and polyphenol content in fruit was statistically significant. Storing these pumpkin varieties resulted in an increment of their total carotenoid and polyphenol content, but it did not have any statistical significance.

Maturity at harvest and postharvest quality of summer squash

Abstract: The objective of this work was to evaluate the influence of harvest at maturity on the composition, quality, and postharvest life of zapallito squash (Cucurbita maxima var. zapallito). Fruit were harvested at three developmental stages - small, medium, and large, with 30, 70, and 90±10-mm diameter, respectively - and were stored at 0 and 5°C for 26 days and, then, at 20°C for 2 days. The following parameters were determined: respiration, firmness, color, chlorophyll content, carotenoids, sugars, acidity, phenolic compounds, antioxidants, decay, mass loss, and chilling injury (CI). Small light-colored squashes were more prone to dehydration and decay. Delaying harvest markedly reduced fruit carotenoid contents, acidity, and respiration rate; however, it did not affect firmness nor sugar content. Chlorophyll showed an increasing trend during fruit development. Small squashes had 100% higher levels of phenolic compounds and antioxidants than medium and large fruit, but were more sensitive to CI. No differences for CI susceptibility were observed between medium and large fruit. The quality of small, medium, and large squashes remained acceptable for 12, 19, and 26 days at 5ºC, respectively, plus 2 days at 20ºC.

AtPDS overexpression in tomato: exposing unique patterns of carotenoid self-regulation and an alternative strategy for the enhancement of fruit carotenoid content.

SummaryThe regulation of plant carotenogenesis is an active research area for both biological discovery and practical implementation. In tomato (Solanum lycopersicum), we demonstrate additional bottlenecks exist in the poly‐cis‐transformation of phytoene to lycopene in the context of ripening‐induced PSY1 expression and activity and reveal phytoene desaturase (PDS), as a target for manipulation towards elevated lycopene content in maturing tomato fruit. Overexpression of Arabidopsis PDS, AtPDS, elevated PDS transcript abundance in all aerial tissues resulting in both altered carotenoid accumulation and associated pathway gene expression in a tissue‐specific manner. Significant increases in downstream carotenoids (all‐trans‐lycopene and β‐carotene) and minimal changes in carotenogenic gene expression (carotenoid isomerase‐like 1, CRTIL1) suggest overexpression of heterologous AtPDS in tomato circumvents endogenous regulatory mechanism observed with previous strategies. In transgenic leaves, depletion of the PDS substrate, phytoene, was accompanied by minor, but significant increases in xanthophyll production. Alterations in the leaf carotenogenic transcript profile, including the upstream MEP pathway, were observed revealing unique feedback and feedforward regulatory mechanisms in response to AtPDS overexpression. AtPDS overexpression in the background of the tangerine (carotenoid isomerase, CRTISO) mutant exposes its potential in elevating downstream cis‐lycopene accumulation in ripe tomato fruit, as cis‐lycopene is more bioavailable yet less abundant than all‐trans‐lycopene in the wild‐type control. In summary, we demonstrate the limitation of PDS in ripening fruit, its utility in modifying carotenoid profiles towards improved quality, and reveal novel carotenoid pathway feedback regulation.

Winter squash (Cucurbita moschata Duch) fruit as a source of biologically active components after its thermal treatment

To one of the most valuable pumpkin fruit belongs winter squash (Cucurbita moschata Duch). The aim of this work was to assess the quality of C. moschata fruit and to assess the dynamics of compositional changes after the heat treatment of the pulp. We used six varieties Liscia, Orange, Hannah, UG 201 F1, Waltham, Serpentine. In the samples were analyzed carbohydrate content (glucose, fructose and sucrose), total polyphenols, total carotenoids and antioxidant activity. The fresh pulp and pulp after the heat treatment were observed. Content of carbohydrates was determined by FTIR infrared spectroscopy. Content of total carotenoids, polyphenols and antioxidant activity was determined by spectrophotometry. As the dominant sugar was found to be sucrose. The lowest content of all carbohydrates was found in the variety Serpentine. Fructose content ranged from 7.59 to 12.32 g.100 g-1 dry matter, glucose content from 7.23 to 9.79 g.100 g-1 dry matter and sucrose content 38.67 to 55.94 g.100 g-1 dry matter. After processing there was found a decrease in the sucrose and the slight increase in glucose and fructose content. Total carotenoid content in fruits ranged from 39.01 to 97.67 g mg.100 g-1 dry matter, the content of total polyphenols from 443.98 to 565.44 mg GAE.100 g-1 dry matter and antioxidant activity from 680.18 to 851.87 mg AA.100 g-1 dry matter. After the heat treatment, there was found some decrease in total carotenoids, polyphenols and antioxidant activity as well.

Differential expression of carotenoid biosynthetic pathway genes in two contrasting tomato genotypes for lycopene content.

Tomato (Solanum lycopersicum L.) is one of the model plant to study carotenoid biosynthesis. In the present study, the fruit carotenoid content were quantified at different developmental stages for two contrasting genotypes, viz. IIHR-249-1 and IIHR-2866 by UPLC. Lycopene content was high in IIHR-249-1 (19.45 mg/100 g fresh weight) compared to IIHR-2866 (1.88 mg/100 g fresh weight) at the ripe stage. qPCR was performed for genes that are involved in the carotenoid biosynthetic pathway to study the difference in lycopene content in fruits of both the genotypes. The expression of Phytoene synthase (PSY) increased by 36-fold and Phytoene desaturase (PDS) increased by 14-fold from immature green stage to ripe stage in IIHR-249-1. The expression of Chloroplast lycopene beta-cyclase (LCY-B) and Chromoplast lycopene beta cyclase (CYC-B) decreased gradually from the initial stage to the ripe stage in IIHR-249-1. IIHR 249-1 showed 3- and 1.8-fold decrease in gene expression for Chloroplast lycopene beta-cyclase (LCY-B) and Chromoplast lycopene beta-cyclase (CYC-B) .The F2 hybrids derived from IIHR-249-1 and IIHR-2866 were analysed at the ripe stage for lycopene content. The gene expression of Chloroplast lycopene beta-cyclase (LCY-B) and Chromoplast lycopene beta-cyclase (CYC-B) in high and low lycopene lines from F2 progenies also showed the decrease in transcript levels of both the genes in high lycopene F2 lines. We wish to suggest that the differential expression of lycopene beta-cyclases can be used in marker-assisted breeding.

Pre-harvest and post-harvest factors affecting ascorbic acid and carotenoid content in fruits and vegetables

Pre-harvest and post-harvest factors affecting ascorbic acid and carotenoid content in fruits and vegetables

The Phytoene synthase gene family of apple (Malus x domestica) and its role in controlling fruit carotenoid content.

BackgroundCarotenoid compounds play essential roles in plants such as protecting the photosynthetic apparatus and in hormone signalling. Coloured carotenoids provide yellow, orange and red colour to plant tissues, as well as offering nutritional benefit to humans and animals. The enzyme phytoene synthase (PSY) catalyses the first committed step of the carotenoid biosynthetic pathway and has been associated with control of pathway flux. We characterised four PSY genes found in the apple genome to further understand their involvement in fruit carotenoid accumulation.ResultsThe apple PSY gene family, containing six members, was predicted to have three functional members, PSY1, PSY2, and PSY4, based on translation of the predicted gene sequences and/or corresponding cDNAs. However, only PSY1 and PSY2 showed activity in a complementation assay. Protein localisation experiments revealed differential localization of the PSY proteins in chloroplasts; PSY1 and PSY2 localized to the thylakoid membranes, while PSY4 localized to plastoglobuli. Transcript levels in ‘Granny Smith’ and ‘Royal Gala’ apple cultivars showed PSY2 was most highly expressed in fruit and other vegetative tissues. We tested the transient activation of the apple PSY1 and PSY2 promoters and identified potential and differential regulation by AP2/ERF transcription factors, which suggested that the PSY genes are controlled by different transcriptional mechanisms.ConclusionThe first committed carotenoid pathway step in apple is controlled by MdPSY1 and MdPSY2, while MdPSY4 play little or no role in this respect. This has implications for apple breeding programmes where carotenoid enhancement is a target and would allow co-segregation with phenotypes to be tested during the development of new cultivars.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-015-0573-7) contains supplementary material, which is available to authorized users.

Silencing SlELP2L, a tomato Elongator complex protein 2-like gene, inhibits leaf growth, accelerates leaf, sepal senescence, and produces dark-green fruit.

The multi-subunit complex Elongator interacts with elongating RNA polymerase II (RNAPII) and is thought to facilitate transcription through histone acetylation. Elongator is highly conserved in eukaryotes, yet has multiple kingdom-specific functions in diverse organisms. Recent genetic studies performed in Arabidopsis have demonstrated that Elongator functions in plant growth and development, and in response to biotic and abiotic stress. However, little is known about its roles in other plant species. Here, we study the function of an Elongator complex protein 2-like gene in tomato, here designated as SlELP2L, through RNAi-mediated gene silencing. Silencing SlELP2L in tomato inhibits leaf growth, accelerates leaf and sepal senescence, and produces dark-green fruit with reduced GA and IAA contents in leaves, and increased chlorophyll accumulation in pericarps. Gene expression analysis indicated that SlELP2L-silenced plants had reduced transcript levels of ethylene- and ripening-related genes during fruit ripening with slightly decreased carotenoid content in fruits, while the expression of DNA methyltransferase genes was up-regulated, indicating that SlELP2L may modulate DNA methylation in tomato. Besides, silencing SlELP2L increases ABA sensitivity in inhibiting seedling growth. These results suggest that SlELP2L plays important roles in regulating plant growth and development, as well as in response to ABA in tomato.

An increase of lycopene content in tomato fruit is associated with a novel Cyc-B allele isolated through TILLING technology

Tomato Cyc-B gene encodes a chromoplast-specific lycopene β-cyclase that converts lycopene to β-carotene during ripening of the fruit. By screening the tomato Red Setter mutant population with the TILLING method, we identified eight new alleles at the Cyc-B locus. Results of greenhouse phenotypic analysis revealed that the novel A949G Cyc-B allele produced modifications in the carotenoid profile and content of tomato petals and fruit. The cyc-b7 genotype, carrying the A949G Cyc-B allele, was therefore evaluated in an open field trial for standard agronomic traits as well as carotenoid content of the fruit. Results of the field trial confirmed that the induced A949G missense mutation favored the accumulation of lycopene in the fruit with no detrimental effects on the yield or on other agronomic and technological properties such as fruit firmness and Brix degree of fruit juice. On the basis of these results, it can be affirmed that the A949G Cyc-B allele constitutes a useful new genetic variant which can be used for improving carotenoid content in tomato fruit and for the development of new tomato commercial lines. Finally, the results presented here furthermore demonstrate that TILLING is a powerful methodology not only as a confirmatory system for gene functional analysis but also for selecting new gene variants useful for genetic improvement of important crops.

Carotenoid Content in Field-grown versus Greenhouse-grown Peppers: Different Responses in Leaf and Fruit

The carotenoid content of fresh fruits, like chiles or peppers (Capsicum annuum L.), is a desirable fruit quality trait because these compounds increase the nutritional value of the fruit. Carotenoids in general serve as antioxidants, whereas specific carotenoids are pro-vitamin A types and yet others are necessary for retinal pigments. In the plant, carotenoids function to harvest light energy during photosynthesis, act as antioxidants in multiple cell types, and pigment fruit and flowers to attract pollinators and seed dispersal agents. All of these cells presumably accumulate carotenoids through the same biosynthetic pathway. We investigated the relationship between light levels in the growth environment and the carotenoid levels that accumulated in mature fruit and leaves. Three chile cultivars with orange fruit, ‘Fogo’, ‘Orange Grande’, and ‘NuMex Sunset’, were grown under three different light conditions, shaded greenhouse, unshaded greenhouse, and field in Las Cruces, NM. Foliar carotenoid increased approximately twofold with increased light, whereas carotenoid content in fruit decreased two- to threefold with increased light. All cultivars showed identical trends with light despite having cultivar-specific carotenoid accumulation patterns in their fruit.