Red Color Development Research Articles

Influence of pre-harvest fruit bagging and plant cover on peel colour, physical appearance and quality traits of pomegranate fruits in arid conditions

Aim: To study the influence of fruit bagging and plant cover on microclimate modification and its role on external quality traits and physico-chemical fruit characteristics of pomegranate cv. Bhagwa in arid conditions. Methodology: Fruits bagging was done with single layer bags of news paper (NP), brown paper (BP), white parchment paper (PP), non-woven polypropylene (NWP), complete plant covering with non-woven polypropylene (CNWP), and un-bagged with no cover was kept as control. Bagging was done 60 days after fruit set and continued until harvest, each year. Results: Bagging and plant covering modified the microenvironment which positively influenced the fruit development. Among the bags, inside air temperature was higher in BP followed by NP, PP and NWP, while RH was higher in PP. PP bags was most effective for the development of attractive red peel color (a* value = 44.4) followed by NWP (a* value = 39.6) or CNWP (a* value = 36.6). All four bags were able to check thrips incidence completely, while PP bagging provided physical scratches or fungal spot free fruits. Physical attributes of fruits including fruit weight, aril weight, peel thickness and juice content were considerably affected. Interpretation: Fruit bagging or plant covering is simple, cost-effective and eco- friendly way to produce quality safe pomegranate fruits under adverse climatic conditions of arid regions.

Efficiency of pre-harvest application of 1-MCP (Harvista™ 1.3 SC) to delay maturation of ‘Cripps Pink’ apple fruit

The objective of this study was to evaluate the efficiency of pre-harvest application of 1-methylcyclopropene-α-cyclodextrin in concentrated magnesium sulfate solution (1-MCP; Harvista™ 1.3 SC) to delay maturation of ‘Cripps Pink’ apple fruit. 1-MCP was sprayed at 0, 75, 150, 225 and 300 mg L−1, seven days before the anticipated harvest time (DBAH). Aminoethoxyvinylglycine (AVG, 124 mg L−1, Retain®) was sprayed 28 DBAH, as a commercial control treatment. Fruit maturation was delayed by increasing 1-MCP concentration. 1-MCP at concentrations ≥ 150 mg L−1 delayed by six and 15 days the time for the fruit to reach the harvest firmness of 71.1 N and 66.7 N, respectively, compared to untreated fruit. Skin color changes (red color development and background degreening) were inhibited by increasing 1-MCP concentrations up to 300 mg L−1. The reduction of ethylene synthesis, and the loss of flesh firmness and starch content occurred by increasing 1-MCP concentrations up to 98.2, 134.5 and 182.3 mg L−1, respectively. The AVG treatment delayed ethylene production and skin red color development at harvest more markedly than the highest concentration of 1-MCP (300 mg L−1). However, both treatments (AVG and 1-MCP at 300 mg L−1) had late harvested fruit (28 days after spraying 1-MCP) with percentage of skin red color below 40%. The results show that 1-MCP delays maturity, but concentrations ≥135 mg L−1 do not improve its efficacy on preserving flesh firmness while might inhibit skin red color development in ‘Cripps Pink’ apples.

Development and genetics of red coloration in the zebrafish relative Danio albolineatus.

Animal pigment patterns play important roles in behavior and, in many species, red coloration serves as an honest signal of individual quality in mate choice. Among Danio fishes, some species develop erythrophores, pigment cells that contain red ketocarotenoids, whereas other species, like zebrafish (D. rerio) only have yellow xanthophores. Here, we use pearl danio (D. albolineatus) to assess the developmental origin of erythrophores and their mechanisms of differentiation. We show that erythrophores in the fin of D. albolineatus share a common progenitor with xanthophores and maintain plasticity in cell fate even after differentiation. We further identify the predominant ketocarotenoids that confer red coloration to erythrophores and use reverse genetics to pinpoint genes required for the differentiation and maintenance of these cells. Our analyses are a first step toward defining the mechanisms underlying the development of erythrophore-mediated red coloration in Danio and reveal striking parallels with the mechanism of red coloration in birds.

The Complexity of Modulating Anthocyanin Biosynthesis Pathway by Deficit Irrigation in Table Grapes.

Deficit irrigation (DI) is an irrigation scheduling technique that is used in grapes to improve red color development; however, results are not always satisfactory in table grapes. The red color in grapes is mainly due to the plant pigment anthocyanin. In the present study, the anthocyanin biosynthesis in Scarlet Royal grapes (Vitis vinifera L.) grown in the San Joaquin and Coachella Valleys, and subjected to two different DI strategies was investigated. The objective of this study was to identify potential regulatory factors that may lead to potential treatments to improve red color in table grapes, especially under warm climate conditions. In both locations, DI induced the expression of several genes involved in three major pathways that control the red color in table grapes: anthocyanin biosynthesis, hormone biosynthesis, and antioxidant system. DI at veraison induced anthocyanin accumulation and enhanced red color in berries at harvest time. However, anthocyanin accumulation was lower at the Coachella Valley compared to the San Joaquin Valley. The lower level of anthocyanin was associated with lower expression of critical genes involved in anthocyanin biosynthesis, such as flavonoid-3-O-glucosyltransferase (UFGT), myb-related regulatory gene (R2R3-MYB) (MYBA1), basic helix-loop-helix (bHLH) (MYCA1) and the tryptophan-aspartic acid repeat (WDR or WD40) proteins (WDR1). Further, gene expression analysis revealed the association of ABA biosynthesis gene 9-cis-epoxycarotenoid dioxygenase (NCED1), 1-aminocyclopropane-1-carboxylic acid oxidase (ACO3), and the gibberellic acid (GA) catabolic gene GA2 oxidase (GA2ox1) in the induction of anthocyanin biosynthesis. An increase in the chalcone synthase gene (CHS2) was observed in response to DI treatments in both sites. However, CHS2 expression was higher in Coachella Valley after ending the DI treatment, suggesting the involvement of environmental stress in elevating its transcripts. This data was also supported by the lower level of antioxidant gene expression and enzyme activities in the Coachella Valley compared to the San Joaquin Valley. The present data suggested that the lack of grape red coloration could partially be due to the lower level of antioxidant activities resulting in accelerated anthocyanin degradation and impaired anthocyanin biosynthesis. It seems that under challenging warmer conditions, several factors are required to optimize anthocyanin accumulation via DI, including an active antioxidant system, proper light perception, and hormonal balance.

The potential pigmentation-related genes in spider mites revealed by comparative transcriptomes of the red form of Tetranychus urticae.

Colouration in spider mites is due to the presence of carotenoids with diverse colours, including yellows, oranges and reds. Tetranychus urticae has two main colour forms, red and green. Although a ketolase has been implicated in determining the colour, the underlying genetic basis of body colour divergence between the two forms has remained unclear. Based on a combination of comparative transcriptomes and RNA interference, we found that a gene encoding a cytochrome P450 enzyme of the CYP4 clan (CYP389B1) had remarkably high expression in adult females of the red T. urticae, as well as in hybrids obtained by crossing the red and green forms. Down-regulation of this gene by RNA interference resulted in decreased accumulation of red pigment. Up-regulation of the expressions of a scavenger receptor gene (SCARB1) and a mitochondrial glycine transporter (SLC25A38) also strongly contributed to red colour development in adult females. Suppressing the mRNA levels of these genes also resulted in reduced accumulation of red pigment in the three other spider mites with red body colour. Our results provide evidence that the body colour divergence between the two forms is caused by different expressions of pigmentation-related genes, and point to a possible role of a novel cytochrome P450 gene (CYP389B1) in regulating red-orange body colour. These findings expand the number of candidate cytochrome P450 genes involved in endogenous pigmentation and will help to understand their roles in determining colour patterns in mites and other species.

Suppression of red color development associated with anthocyanin accumulation in the epicarp of grape (Vitis labrusca × vinifera cv. Ruby Roman) berries caused by air temperature in daylight periods higher than 33°C during maturation

The effect of high air temperature on the anthocyanin accumulation in the epicarp of 'Ruby Roman' grape (Vitis labruscana × vinifera) berries was examined. Seventeen types of anthocyanin were detected from the epicarp tissue of the matured berries using HPLC. Since a strong positive correlation (P < 0.005, R2 = 0.937) was confirmed between the degree of color density evaluated using a color chart and the total content of anthocyanins quantified separately, it seems possible to trace anthocyanin accumulation using the color chart on each berry during maturation at different air temperatures. Four conditions were designed for cooling the fruit clusters with a spot-cooling system, which can keep air temperature 4–5°C lower for 60–70 days after the full–bloom, i.e. consecutive (0:00–24:00) cooling, daytime (6:00–18:00) cooling, nighttime (18:00–6:00) cooling and no–cooling (control). The degree of color density showed statistically higher (P < 0.05) values in the consecutive–cooling treatment than that of the control through the post–cooling duration (0–15 days after cooling). To clarify the effect of temperature zones with or without daylight on the anthocyanin accumulation in the epicarp, percentage of exposure time to each temperature zone of < 21, 21–24, 24–27, 27–30, 30–33, 33–36 and 36°C ≤ were calculated for both daylight and dark periods, separately. Correlations of the ∆ time% (the amount of difference in percentage of exposure time from the control) with the ∆ color degree (the amount of difference in degree of color density from the control) in the daylight period were positive at temperature zones of < 30°C, but turned to negative at those of 30°C ≤. The fact that correlation coefficient was statistically significant (P < 0.05) at the temperature zones of 27–30°C (positive) and 33–36°C (negative) in the daylight period shows that the threshold where the anthocyanin accumulation starts to be suppressed exists within 30–33°C.

Effect of storage temperature and light irradiation on respiration rate, red color development, and gene expression involved in carotenoid synthesis in green bell pepper (Capsicum annuum L.)

Effect of storage temperature and light irradiation on respiration rate, red color development, and gene expression involved in carotenoid synthesis in green bell pepper (<i>Capsicum annuum</i> L.)

Fruit quality of ‘Braeburn’ apple trees sprayed at post-bloom and preharvest with prohexadione-calcium and GA4+7

Abstract The objective of this study was to assess the effects of post-bloom (PB) or preharvest (PH) treatments of ‘Braeburn’ apple trees with prohexadione-calcium (ProCa; 300 mg L-1), an inhibitor of gibberellins biosynthesis, or GA4+7 (300 mg L-1) on fruit quality at harvest and after storage (four months at 0±0.5 oC, followed by five days of shelf life). PB treatments started 15 days after full bloom, with one application every week and six applications in total. PH treatments started five weeks before anticipated harvest, with one application every week and four applications in total. Control trees were sprayed with water. GA4+7 PB increased length/diameter ratio, and GA4+7 PH increased titratable acidity (TA) and flesh firmness and slightly reduced red color of the fruit at harvest. ProCa PB and PH reduced ethylene production rate, delayed starch degradation and reduced soluble solids content of the fruit at harvest, and ProCa PH maintained firmness at harvest and after storage and TA of the fruit after storage. ProCa PB or PH delayed the loss of skin green background color at harvest, while at both treatment timings reduced the development of skin red color, but with a much stronger effect when sprayed PH than PB.

Photoselective Protective Netting Improves "Honeycrisp" Fruit Quality.

High temperatures, wind, and excessive sunlight can negatively impact yield and fruit quality in semi-arid apple production regions. Netting was originally designed for hail protection, but it can modify the light spectrum and affect fruit quality. Here, pearl, blue, and red photoselective netting (≈20% shading factor) was installed in 2015 over a commercial “Cameron Select® Honeycrisp” orchard. Our research objectives were to (1) describe the light quantity and quality under the colored nets compared to an uncovered control and (2) investigate the effect of Photoselective nets on “Honeycrisp” apple quality for two growing seasons. Light transmittance and scattering for each treatment were measured with a spectroradiometer, and samples for fruit quality analyses were collected at harvest. PAR (photosynthetic active radiation), UV, blue, red, and far-red light were lower underneath all netting treatments compared to an uncovered control. The scattered light was higher under the pearl net compared to other colors, while red and far-red light were lower under the blue net. For two consecutive years, trees grown under the photoselective nets intercepted more incoming light than the uncovered trees with no differences among the three colors. In both years, trees under red and blue nets had more sunburn-free (clean) apples than pearl and control. Red color development for fruit was lower when nets were used. Interestingly, bitter pit incidence was lower underneath red nets for both years. Other than red color development, “Honeycrisp” fruit quality was not appreciably affected by the use of netting. These results highlight the beneficial effect of nets in improving light quality in orchards and mitigating physiological disorders such as bitter pit in “Honeycrisp” apple.

Eco-friendly Li3InB2O6 based red pigments for various IR blocking cool coating applications

Abstract New red chromatic inorganic powder pigments were prepared by the introduction of Mn3+ in the host lattice of monoclinic Li3InB2O6. Substitution of Mn3+ ion in the indium site of host lattice changed the powder color from grey-white to (x = 0) red with (x = 0.08). The absorption spectra of the synthesized samples revealed that the development of red color occurred might be due to the crystal field splitting of Jahn-Teller distorted MnO6 octahedra. An attempt was also made to distort the crystal field around the Mn3+via the doping of larger alkali metal ions into the Li sites of Li3In0.92Mn0.08B2O6 host lattice. This substitution effect altered absorption properties translated in enhancing the red chromaticity for Li2.95Na0.05In0.92Mn0.08B2O6 with a CIE redness value of (a* = 29.5). Furthermore, the developed pigments and the substrate material coated with them showed good NIR solar reflectance in the range of 700–2500 nm. Finally, the thermal shielding performance of the synthesized pigments was evaluated for their usage as building roof coatings.

Relative fitness of decoy coloration is mediated by habitat type

Predator-prey interactions can be important drivers of morphological evolution, and antipredator traits in particular. Further, ecological context can be an important factor shaping the evolution of these traits. However, the role of ecological factors such as habitat structure in altering predator-based selection is not well known for antipredator traits such as decoy coloration. We used a combination of a natural history collection survey and a clay model experiment in open- and closed-canopy habitats to study how ecological context alters the fitness benefit of either red or blue decoy coloration in skinks. We found that the development and ecology of red decoy coloration of mole skinks differed substantially from blue tail coloration of other sympatric skink species. Mole skinks do not reach the body size of sympatric species of skinks and retain decoy coloration throughout development. Both patterns of scarring in museum specimens and attacks on plasticine models suggest that red coloration serves as a decoy, attracting attacks to the autotomous tail. While predation rates were similar across habitats, models with red tails were attacked far less frequently in open habitats than models with blue tails, while attack rates were similar in closed habitats. Our results suggest that red decoy coloration in mole skinks could be an adaptation to relatively open-canopy habitats. Our study has important implications for understanding how habitat structure and predator-based selection can alter the evolutionary dynamics of decoy coloration.

Improving the Red Color and Fruit Quality of ‘Kent’ Mango Fruit by Pruning and Preharvest Spraying of Prohydrojasmon or Abscisic Acid

Pre-harvest application of prohydrojasmon (PDJ) or abscisic acid (ABA) induces the red color in fruits that were exposed to sunlight at the orchard. In this large-scale work, we evaluated the effect of two different pruning techniques of ‘Kent’ mango orchards, one leading to opening the orchard canopy to expose as much fruit as possible to sunlight, while the second pruning leads to square-shaped trees and subsequently reduces the amount of sunlight reaching the fruit. These two pruning methods were combined with preharvest spraying with prohydrojasmon (PDJ) or abscisic acid (ABA) using two different types of sprayers, i.e., regular and air-jet sprayer. Pruning the canopy of the orchards to open and closed trees exposed 80% or 30% of fruits to sunlight, respectively. Both of the application with air-jet and regular sprayers effectively covered the fruit without causing fruit detachment and damage to yield. Both the phytohormones (PDJ and ABA) application treatments induced red blush skin, red intensity, anthocyanin, and flavonoids, particularly in fruit grown outside the tree canopy in both open and closed trees. PDJ and ABA treatments exhibited marginally reduced acidity than the untreated control, while the brix was not affected much by any of the treatments. Besides these, exposure to sunlight and PDJ treatment also reduced postharvest decay and increased chlorophyll degradation and yellowing in comparison to the controls. This study promoted applicative evidence about the positive effects of exposure to sunlight, prohydrojasmon (PDJ), and abscisic acid (ABA) on red color development without compromising the mango fruit’s quality.

Red and White Chinook Salmon (Oncorhynchus tshawytscha): Differences in the Transcriptome Profile of Muscle, Liver, and Pylorus

Astaxanthin (Ax), the main carotenoid responsible for the distinct red flesh color in salmonids (Oncorhynchus, Salvelinus, Salmo, and Parahucho), is added to the diet of farmed fish at a substantial cost. Despite the great economical value for the salmon industry, the key molecular mechanisms involved in the regulation of muscle coloration are poorly understood. Chinook salmon (Oncorhynchus tshawytscha) represent an ideal model to study flesh coloration because they exhibit a distinct color polymorphism responsible for two color morphs, white and red flesh pigmented fish. This study was designed to identify the molecular basis for the development of red and white coloration of fish reared under the same experimental conditions and to better understand the absorption mechanism of Ax in salmonids. Pyloric caeca, liver, and muscle of both groups (n = 6 each) were selected as the most likely critical target organs to be involved respectively in the intestinal uptake, metabolism, and retention of Ax. Difference in the transcriptome profile of each tissue using next-generation sequencing technology was conducted. Ten KEGG pathways were significantly enriched for differentially expressed genes between red and white salmon pylorus tissue, while none for the transcriptome profile in the other two tissues. Differential expressed gene (DE) analyses showed that there were relatively few differences in muscle (31 DE genes, p < 0.05) and liver (43 DE genes, p < 0.05) of white and red Chinook salmon compared approximately 1125 DE genes characterized in the pylorus tissue, with several linked to Ax binding ability, absorption, and metabolism.

Decreased Protein Abundance of Lycopene β-Cyclase Contributes to Red Flesh in Domesticated Watermelon.

Red-fleshed watermelons (Citrullus lanatus) that accumulate lycopene in their flesh cells have been selected and domesticated from their pale-fleshed ancestors. However, the molecular basis of this trait remains poorly understood. Using map-based cloning and transgenic analysis, we identified a lycopene β-cyclase (ClLCYB) gene that controls the flesh color of watermelon. Down-regulation of ClLCYB caused the flesh color to change from pale yellow to red, and ClLCYB overexpression in the red-fleshed line caused the flesh color to change to orange. Analysis of ClLCYB single-nucleotide polymorphisms using 211 watermelon accessions with different flesh colors revealed that two missense mutations between three haplotypes (ClLCYB red , ClLCYB white , and ClLCYB yellow ) were selected and largely fixed in domesticated watermelon. Proteins derived from these three ClLCYB haplotypes were localized in plastids to catalyze the conversion of lycopene to β-carotene and showed similar catalytic abilities. We revealed that ClLCYB protein abundance, instead of ClLCYB transcript level, was negatively correlated with lycopene accumulation. Different amounts of ClLCYB protein degradation among the ClLCYB haplotypes were found in ClLCYB transgenic Arabidopsis (Arabidopsis thaliana) lines. After treatment with the proteasome inhibitor MG132, the concentration of ClLCYBred increased noticeably compared with other ClLCYB proteins. These results indicate that natural missense mutations within ClLCYB influence ClLCYB protein abundance and have contributed to the development of red flesh color in domesticated watermelon.

Phenolic Content, Color Development, and Pigment−Related Gene Expression: A Comparative Analysis in Different Cultivars of Strawberry during the Ripening Process

Globally, the strawberry is one of the most widely consumed fruits, but under certain environmental conditions, it exhibits inadequate red color development, causing economic losses due to lower product quality. In order to evaluate if changes in color are cultivar-specific and environmentally dependent, a comparative study of anthocyanin accumulation, total phenolic, total flavonoid content analysis and additionally a transcriptional profile of pigment-related genes in “Camarosa,” “Cristal,” “Monterey,” and “Portola” (four strawberry cultivars) was performed. These showed an increase in their red coloration during fruit development. The anthocyanin accumulation in the four cultivars was related to the particular progress of the transcriptional activity of genes involved in the biosynthesis of flavonoid pigments. The greatest increase was observed in “Monterey” and “Camarosa”; thus, we have found a correlation between fruit color redness and total anthocyanins only in these cultivars. However, a positive correlation between the mRNA abundance of FaF3′H and FaFLS and the total flavonoids content was found in all cultivars at early stages of ripening. Finally, we found correlations between color and other important physiological properties such as SSC/TA, weight, and aroma expressed as total esters. These results could be useful in making decisions in future breeding programs to improve the content of healthy compound content in strawberry fruit.

Effects of covering inter-row orchard floor with reflective films on light distribution, photosynthesis, coloration and quality of ‘Fuji’ apples

The effect of hot and dry summers, typical of Mediterranean climates, together with inappropriate canopy management, strongly restricts apples red color development. The ‘Fuji’ apples market demands not only fruits with larger sizes, crunchy textures and sweet flavors but also with intense and complete red coloration skin. Portuguese growers face additional difficulties by the predominance of old clones and fast-changing needs of the market, requiring a different technical approach and the introduction of new technologies. The use of reflective materials between tree rows is known by its effects on enhancing red color development without reducing fruit quality and it was tested in Portuguese conditions in an orchard of ‘Fuji Fubrax’ apple (Malus domestica). White polypropylene UV-stabilized reflective film, Reflectex® (Carreta Tessitura, Carre, Italy), was installed 22 days before the first harvest, in alternate rows, leaving uncovered the first 50 cm closer to the trunk. PAR reflection measured at 50 cm height, in the middle of the rows with spontaneous vegetation increased from 9.1 to 53.6% when covered with white reflective film. In spite of soil PAR reflection measured under the canopy at solar noon be low, average reflection in the first linear meter increased from 3 to 11% in the west side and from 1 to 6.5% in the east side, with significant gains in the first 50 cm due to the effect of the film. There was also a positive effect on the side of the trees without film, resulting from reflected radiation into the canopy. These differences were responsible for higher photosynthetic rates measured outside and inside the trees with the film placed laterally, some of these results being supported by chlorophyll content index and specific leaf area measurements. Covering the orchard floor with reflective films was very effective in improving fruit coloration (lower hue values, so redder fruits), showing significant differences and similar color between fruits harvested inside the canopy from the side with the film and fruits from the outside of the canopy without film. Positive effects were also found in average fruit weight, firmness and total soluble solids (increase of about 5-10% in Brix values). These results should be confirmed in a long-term program and others reflective materials assessed.

Enhancement of the antioxidant capacity of ripe tomatoes by the application of a hot water treatment at the mature-green stage

Abstract Plants are constantly exposed to abiotic and biotic stresses, inducing the generation of reactive oxygen species (ROS). In response, the synthesis of antioxidants is upregulated to neutralize the deteriorating effects of ROS. We investigated whether promoting this response could enhance the nutritional and sensory quality of tomatoes. In preliminary experiments, mature green tomatoes were immersed in hot water (HW) at 50 °C for 5 min, 52 °C for 5 min, or 54 °C for 2.5 min (25 °C water for 5 min as control); subsequent experiments utilized 52 °C for 5 min. Following those treatments, we evaluated the changes in color, texture, soluble solids, titratable acidity, and the antioxidant system of the fruit during ripening at 20 °C and 85–90 % relative humidity. The HW treatment of 52 °C for 5 min promoted higher accumulation of carotenoids and lipophilic phenolics, resulting in greater color development and slightly higher antioxidant potential, but did not otherwise affect the composition of ripe fruit; the tomatoes ripened normally after HW immersion, with no firmness differences, but were darker red and less yellow-orange with higher antioxidant potential. Furthermore, we observed that the beneficial effects were more noticeable at early stages of ripening, even in varieties that did not exhibit major differences after reaching full ripeness. In this sense, we found that ‘Florida 47’ and ‘Security 28’ tomatoes have a limited response to HW treatment compared with ‘Soraya’ and especially ‘Tasti Lee’ tomatoes, indicating that there might be genetic constraints on the response in the former varieties. The beneficial effect of immersing the tomatoes in HW was proportional to the heat penetration profile inside the fruit; for example, the 52 °C for 5 min treatment increased the temperature up to 45 °C in the peripheral tissues 4 mm below the fruit surface where the content of carotenoids and lipophilic phenolic compounds was mainly increased; whereas, the tissue temperature was 35 °C at the center of the tomato, where we did not observe any change in composition. In conclusion, the HW immersion used in this research promoted the synthesis of lipophilic antioxidants such as carotenoids in tomato fruit, enhancing red color development and antioxidant potential.

Color Development and Phytochemical Changes in Mature Green Chili (Capsicum annuum L.) Exposed to Red and Blue Light-Emitting Diodes.

Exposure of mature green "Takanotsume" chili fruit to blue and red light-emitting diodes (LEDs) was investigated. The red LED accelerated the red color development of chili as indicated by higher a* and chroma values, as well as lower hue angle and total chlorophyll compared to the blue LED and darkness (control). These were linked to increases in β-carotene, free-capsanthin, and total carotenoids. The carotenoid biosynthesis-related genes, lycopene-β-cyclase (Lcyb), β-carotene hydroxylase (CrtZ), and capsanthin/capsolubin synthase (Ccs), were up-regulated by the red LED after 2 days of the experiment. The blue LED was more effective in increasing the expression of the phytoene synthase (Psy) gene at day 1 of experiment. The total phenolic, vitamin C content, and antioxidant capacity were also higher in the blue LED-treated chili. Results suggest that the responses of each carotenoid-related gene to the light wavelengths and the accumulation of phytochemicals are specific characteristics of this chili cultivar.

Anthocyanin accumulation and differential gene expression in wild-typeand mutant Syzygium malaccense fruits during their growth and ripening

Ripe wild-type Malay apple (Syzygium malaccense) cv. Saraek fruit epidermis is red, whereas a mutant has a white skin. Wild-type and mutant fruit were used as a fruit model to study the regulation and gene expression patterns of anthocyanin biosynthesis and a myeloblastosis (MYB) transcription factor during growth and development. Fruit size, color, anthocyanin composition, and the expression of genes involved in anthocyanin biosyntheses were determined during fruit growth and ripening. Wild-type ripe fruit had a greater diameter and fruit mass than the mutant. The total anthocyanin content was approximately nine-fold higher in wild-type red fruit than in mutant white fruit. The major anthocyanin in the fruit skin of the wild-type was cyanidin-3-O-glucoside with minor amounts of pelargonidin-3-O-glucoside, peonidin-3-O-glucoside, and cyanidin-3,5-O-diglucoside. No anthocyanin was found in mutant fruit. The accumulation of cyanidin-3-O-glucoside during fruit growth and ripening was correlated with red color development and activities of phenylalanine ammonia lyase (PAL) and UDP-glucose:flavonoid-3-O-glucosyltransferase (UFGT). We cloned fragments and characterized seven genes involved in anthocyanin biosynthesis pathway namely phenylalanine ammonia lyase (SmPAL), chalcone synthase (SmCHS), chalcone isomerase (SmCHI), flavanone-3-hydroxylase (SmF3H), dihydroflavonol 4-reductase (SmDFR), leucoanthocyanidin dioxygenase (SmLDOX), and UDP glucose-flavonoid-3-O-glucosyl transferase (SmUFGT), as well as a MYB transcription factor (SmMYB). The expressions of all the genes were determined by semi-quantitative reverse transcription (RT)-PCR and quantitative real-time RT-PCR. The skin of wild-type fruit contained transcripts of all above mentioned genes, whereas the mutant fruit showed no SmUFGT and SmMYB expressions, which correlated with the absence of anthocyanin accumulation during fruit growth and ripening. These results suggest that lack of anthocyanin biosynthesis in mutant fruit may be via the regulation of UFGT and MYB transcription factor expressions.

SWATH-MS-facilitated proteomic profiling of fruit skin between Fuji apple and a red skin bud sport mutant

BackgroundApple is one of the most popular fruit crops world-wide and its skin color is an important quality consideration essential for commercial value. However, the strategy on genetic breeding for red skin apple and the genetic basis of skin color differentiation is very limited and still largely unknown.ResultsHere, we reported a bud sport mutant of Fuji apple with red skin color and enhanced anthocyanins accumulation. Quantitative SWATH-MS (sequential window acquisition of all theoretical spectra-mass spectrometry) proteomics investigations revealed proteome changes in the apple red skin bud mutation and a total of 451 differentially expressed proteins were identified in apple skin. The mutant showed significantly increased expression levels of photosynthesis-related proteins, stress-related proteins as well as anthocyanins biosynthesis pathway. On the other hand, substantial downregulation of mitogen-activated protein kinase 4 (MAPK4) and mevalonate kinase (MVK) were detected, indicating a promising role for the red skin color development in the mutant. Furthermore, we also hypothesize that a post-transcriptional regulation of the skin color formation occurs in the mutant through the advanced SWATH-MS analysis.ConclusionOur work provides important information on the application of proteomic methods for analysing proteomes changes in Fuji apple and highlights a clade of regulatory proteins potentially contributing for the molecular breeding of fruit skin color.