RESUMO
The total phenolic content, anthocyanins, phenolic acids, antioxidant capacity and α-amylase inhibitory activity of black (Aydin Siyahi), purple (Kadife Kemer) and white (Trabzon Kadife) eggplants grown in Turkey were subjected to a comparative investigation. The black cultivar exhibited the highest total phenolic (17,193 and 6552 mg gallic acid equivalent/kg fw), flavonoid (3019 and 1160 quercetin equivalent/kg fw) and anthocyanin (1686 and 6167 g delphinidin-3-O-glucoside equivalent/kg fw) contents in crude extracts of the peel and pulp. The majority of the caffeic acid was identified in the ester (2830 mg/kg fw) and ester-bound (2594 mg/kg fw) forms in the peel of 'Kadife Kemer' and in the glycoside form (611.9 mg/kg fw) in 'Aydin Siyahi', as well as in the pulp of these two eggplants. 'Kadife Kemer' (purple eggplant) contained the majority of the chlorogenic acid in free form (27.55 mg/kg fw), compared to 'Aydin Siyahi' in the ester (7.82 mg/kg fw), glycoside (294.1 mg/kg dw) and ester-bound (2.41 mg/kg fw) forms. The eggplant cultivars (peel and pulp, mg/kg fw) exhibited a relatively high delphinidin-3-O-rutinoside concentration in the peel of 'Aydin Siyahi' (avg. 1162), followed by 'Kadife Kemer' (avg. 336.6), and 'Trabzon Kadife' (avg. 215.1). The crude phenolic extracts of the eggplants exhibited the highest antioxidant capacity values (peel and pulp, µmoL Trolox equivalent/kg fw) of 2,2-diphenyl-1-picrylhydrazyl (DPPH, 8156 and 2335) and oxygen radical absorbance capacity (ORAC, 37,887 and 17,648). The overall results indicate that black and purple eggplants are the cultivars with greater potential benefits in terms of their phenolics and antioxidant values than the white eggplant.
Assuntos
Antioxidantes , Solanum melongena , Antocianinas/análise , Antioxidantes/química , Ésteres/análise , Frutas/química , Fenóis/análise , Extratos Vegetais/químicaRESUMO
Depletion of abundant proteins is one of the effective ways to improve detection and identification of low-abundance proteins. Our previous study showed that protamine sulfate precipitation (PSP) method can deplete abundant ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) from leaf proteins and is suitable for their in-depth proteome investigation. In this study, we provide evidence that the PSP method can also be effectively used for depletion of abundant seed-storage proteins (SSPs) from the total seed proteins of diverse legume plants including soybean, broad bean, pea, wild soybean, and peanut. The 0.05% protamine sulfate (PS) was sufficient to deplete major SSPs from all legumes tested except for peanut where 0.1% PS was required. SDS-PAGE, Western blotting and 2DE analyses of PS-treated soybean and peanut seed proteins showed enriched spots in PS-supernatant than total proteins. Coefficient of variation percentage (%CV) and principal component analysis of 2DE spots support the reproducibility, suitability, and efficacy of the PSP method for quantitative and comparative seed proteome analysis. MALDI-TOF-TOF successfully identified some protein spots from soybean and peanut. Hence, this simple, reproducible, economical PSP method has a broader application in depleting plant abundant proteins including SSPs in addition to RuBisCO, allowing discussion for comprehensive proteome establishment and parallel comparative studies in plants.
Assuntos
Precipitação Química , Fabaceae/metabolismo , Protaminas/química , Proteômica/métodos , Proteínas de Armazenamento de Sementes/metabolismo , Arachis/metabolismo , Eletroforese em Gel Bidimensional , Proteínas de Plantas/metabolismo , Análise de Componente Principal , Sementes/metabolismo , Glycine max/metabolismoRESUMO
The demand for rapid and nondestructive methods to determine chemical components in food and agricultural products is proliferating due to being beneficial for screening food quality. This research investigates the feasibility of Fourier transform near-infrared (FT-NIR) and Fourier transform infrared spectroscopy (FT-IR) to predict total as well as an individual type of isoflavones and oligosaccharides using intact soybean samples. A partial least square regression method was performed to develop models based on the spectral data of 310 soybean samples, which were synchronized to the reference values evaluated using a conventional assay. Furthermore, the obtained models were tested using soybean varieties not initially involved in the model construction. As a result, the best prediction models of FT-NIR were allowed to predict total isoflavones and oligosaccharides using intact seeds with acceptable performance (R2p: 0.80 and 0.72), which were slightly better than the model obtained based on FT-IR data (R2p: 0.73 and 0.70). The results also demonstrate the possibility of using FT-NIR to predict individual types of evaluated components, denoted by acceptable performance values of prediction model (R2p) of over 0.70. In addition, the result of the testing model proved the model's performance by obtaining a similar R2 and error to the calibration model.
RESUMO
Near-infrared reflectance spectroscopy (NIRS) was used as a rapid and nondestructive method to determine the oil content and fatty acid composition in intact seeds of perilla [Perilla frutescens var. japonica (Hassk.) Hara] germplasms in Korea. A total of 397 samples (about 2 g of intact seeds) were scanned in the reflectance mode of a scanning monochromator, and the reference values for the oil content and fatty acid composition were measured by gravimetric method and gas-liquid chromatography, respectively. Calibration equations for oil and individual fatty acids were developed using modified partial least-squares regression with internal cross validation (n = 297). The equations for oil and oleic and linolenic acid had lower standard errors of cross-validation (SECV), higher R2 (coefficient of determination in calibration), and higher ratio of unexplained variance divided by variance (1-VR) values than those for palmitic, stearic, and linoleic acid. Prediction of an external validation set (n = 100) showed significant correlation between reference values and NIRS estimated values based on the standard error of prediction (SEP), r2 (coefficient of determination in prediction), and the ratio of standard deviation (SD) of reference data to SEP. The models for oil content and major fatty acids, oleic and linolenic acid, had relatively higher values of SD/SEP(C) and r2 (more than 3.0 and 0.9, respectively), thereby characterizing those equations as having good quantitative information, whereas those of palmitic, stearic, and linoleic acid had lower values (below 2.0 and 0.7, respectively), unsuitable for screening purposes. The results indicated that NIRS could be used to rapidly determine oil content and fatty acid composition (oleic and linolenic acid) in perilla seeds in the breeding programs for development of high-quality perilla oil.
Assuntos
Ácidos Graxos/análise , Perilla/química , Óleos de Plantas/análise , Sementes/química , Espectroscopia de Luz Próxima ao Infravermelho , Calibragem , Reprodutibilidade dos TestesRESUMO
The distribution and variation of targeted metabolites in soybean seeds are affected by genetic and environmental factors. In this study, we used 192 soybean germplasm accessions collected from two provinces of Korea to elucidate the effects of seed coat color and seeds dry weight on the metabolic variation and responses of targeted metabolites. The effects of seed coat color and seeds dry weight were present in sucrose, total oligosaccharides, total carbohydrates and all measured fatty acids. The targeted metabolites were clustered within three groups. These metabolites were not only differently related to seeds dry weight, but also responded differentially to seed coat color. The inter-relationship between the targeted metabolites was highly present in the result of correlation analysis. Overall, results revealed that the targeted metabolites were diverged in relation to seed coat color and seeds dry weight within locally collected soybean seed germplasm accessions.
Assuntos
Cor , Glycine max/metabolismo , Sementes/metabolismo , Metabolismo dos Carboidratos , Ácidos Graxos/metabolismo , Oligossacarídeos/metabolismo , República da CoreiaRESUMO
Sesame (Sesamum indicum L.) contains abundant lignans including lipid-soluble lignans (sesamin and sesamolin) and water-soluble lignan glycosides (sesaminol triglucoside and sesaminol diglucoside) related to antioxidative activity. In this study, near infrared reflectance spectroscopy (NIRS) was used to develop a rapid and nondestructive method for the determination of lignan contents on intact sesame seeds. Ninety-three intact seeds were scanned in the reflectance mode of a scanning monochromator. This scanning procedure did not require the pulverization of samples, allowing each analysis to be completed within minutes. Reference values for lignan contents were obtained by high-performance liquid chromatography analysis. Calibration equations for lignans (sesamin and sesamolin) and lignan glycosides (sesaminol triglucoside and sesaminol diglucoside) contents were developed using modified partial least squares regression with internal cross-validation (n = 63). The equations obtained had low standard errors of cross-validation and moderate R2 (coefficient of determination in calibration). The prediction of an external validation set (n = 30) showed significant correlation between reference values and NIRS predicted values based on the SEP (standard error of prediction), bias, and r2 (coefficient of determination in prediction). The models developed in this study had relatively higher values (more than 2.0) of SD/SEP(C) for all lignans and lignan glycosides except for sesaminol diglucoside, which had a minor amount, indicating good correlation between the reference and the NIRS estimate. The results showed that NIRS, a nondestructive screening method, could be used to rapidly determine lignan and lignan glycoside contents in the breeding programs for high quality sesame.
Assuntos
Glicosídeos/análise , Lignanas/análise , Sementes/química , Sesamum/química , Espectroscopia de Luz Próxima ao Infravermelho , Calibragem , Reprodutibilidade dos TestesRESUMO
A new vector using Soybean yellow common mosaic virus (SYCMV) was constructed for gene function study or heterologous protein expression in soybeans. The in vitro transcript with a 5' cap analog m7GpppG from an SYCMV full-length infectious vector driven by a T7 promoter infected soybeans (pSYCMVT7-full). The symptoms observed in the soybeans infected with either the sap from SYCMV-infected leaves or pSYCMVT7-full were indistinguishable, suggesting that the vector exhibits equivalent biological activity as the virus itself. To utilize the vector further, a DNA-based vector driven by the Cauliflower mosaic virus (CaMV) 35S promoter was constructed. The complete sequence of the SYCMV genome was inserted into a binary vector flanked by a CaMV 35S promoter at the 5' terminus of the SYCMV genome and a cis-cleaving ribozyme sequence followed by a nopaline synthase terminator at the 3' terminus of the SYCMV genome (pSYCMV-full). The SYCMV-derived vector was tested for use as a virus-induced gene silencing (VIGS) vector for the functional analysis of soybean genes. VIGS constructs containing either a fragment of the Phytoene desaturase (PDS) gene (pSYCMV-PDS1) or a fragment of the small subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase (RbcS) gene (pSYCMV-RbcS2) were constructed. Plants infiltrated with each vector using the Agrobacterium-mediated inoculation method exhibited distinct symptoms, such as photo-bleaching in plants infiltrated with pSYCMV-PDS1 and yellow or pale green coloring in plants infiltrated with pSYCMV-RbcS2. In addition, down-regulation of the transcripts of the two target genes was confirmed via northern blot analysis. Particle bombardment and direct plasmid DNA rubbing were also confirmed as alternative inoculation methods. To determine if the SYCMV vector can be used for the expression of heterologous proteins in soybean plants, the vector encoding amino acids 135-160 of VP1 of Foot-and-mouth disease virus (FMDV) serotype O1 Campos (O1C) was constructed (pSYCMV-FMDV). Plants infiltrated with pSYCMV-FMDV were only detected via western blotting using the O1C antibody. Based on these results, we propose that the SYCMV-derived vector can be used for gene function study or expression of useful heterologous proteins in soybeans.
Assuntos
Engenharia Genética/métodos , Vetores Genéticos , Glycine max/genética , Vírus do Mosaico/genética , Proteínas Recombinantes/biossíntese , Proteínas do Capsídeo/genética , Caulimovirus/genética , Regulação para Baixo , Regulação da Expressão Gênica de Plantas , Inativação Gênica , Fenótipo , Folhas de Planta/virologia , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas , RNA Viral/genética , Glycine max/metabolismo , Glycine max/virologiaRESUMO
BACKGROUND: Anthocyanins have been shown to inhibit cancer cell growth by suppressing oxidative stress and inflammatory responses. The purpose of this study was to investigate the effects of an anthocyanin-rich extract (AE) from black soybean coat on intestinal carcinogenesis. METHODS: Apc (Min/+) mice were fed a diet of 0.2% or 0.5% AE for 7 weeks. We analyzed the number of intestinal tumors, oxidative stress and inflammatory markers associated with ß-catenin and cytosolic phospholipase A2 (cPLA2) signals. The number of intestinal tumors, and cellular expression of ß-catenin were determined. RESULTS: The number of intestinal tumors was significantly lower in mice fed a 0.5% AE diet compared to those of the other groups. Cytosolic ß-catenin expression was significantly decreased in the AE supplemented groups compared to that of the control animals. In addition, mucosa expression of cyclooxygenase-2 and cPLA2 were also significantly decreased in the 0.5% AE group, by 32% and 62%, respectively, compared to the control group. CONCLUSIONS: These results suggest that dietary AE reduced the development of intestinal tumors, possibly through the ability to suppress oxidative stresses, decreasing inflammatory responses mediated by ß-catenin associated signals.
RESUMO
This investigation was conducted to determine the structures and amounts of anthocyanins obtained from seed coats of kidney bean (Phaseolus vulgaris L.) cultivated in Korea. Anthocyanins in the seed coat of kidney bean were extracted with 1% HCl/20% CH(3)OH, and the crude anthocyanin extracts were purified by semipreparative HPLC. Five major anthocyanins were isolated, and their chemical structures were identified by spectroscopic methods (UV-vis, LC/ES-MS, and 1H and 13C NMR). The structures of these five anthocyanins were elucidated as cyanidin 3,5-diglucoside, delphinidin 3-glucoside, cyanidin 3-glucoside, petunidin 3-glucoside, and pelargonidin 3-glucoside. Using RP-HPLC with photodiode array detection, each of the five anthocyanins was separated within 12 min by using a gradient elution. It was proved that the application of RP-HPLC could be an excellent method for determining the composition and contents of anthocyanins in kidney bean. The preponderance of pelargonidin 3-glucoside and delphinidin 3-glucoside are observed in red and black kidney beans, respectively. However, in this study, it is reported for the first time that the contents and composition of anthocyanins in speckled seed depend on the classes of speckle color. The contents of cyanidin 3,5-diglucoside, delphinidin 3-glucoside, cyanidin 3-glucoside, petunidin 3-glucoside, pelargonidin 3-glucoside, and total anthocyanins in seed coats of 16 kidney beans cultivated in Korea were in the ranges of 0-0.04, 0-2.61, 0-0.12, 0-0.17, 0-0.59 and 0-2.78 mg/g of dried seed coats, respectively.
Assuntos
Antocianinas/análise , Phaseolus/química , Sementes/química , Antocianinas/química , Cromatografia Líquida de Alta Pressão , Coreia (Geográfico) , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Extratos Vegetais/química , Análise EspectralRESUMO
Near-infrared reflectance spectroscopy (NIRS) was used to determine the contents of caffeine and nine individual catechins in tea leaves. A total of 665 samples were scanned by NIRS, and also by high performance liquid chromatography coupled to a diode array detector to determine the contents of caffeine and nine individual catechins. The calibration models for caffeine, EGC, C, EGCG, EC, ECG, and total catechins had high r(2) (more than 0.90) and RSP (the ratio of standard deviation of reference data to SEP(C) in the external validation set) values (more than 4.1), indicating a good correlation between reference values and NIRS predicted values. In contrast, the calibration models of GC and EGCG-3Me had low r(2) and RSP values (below 0.8 and 2.0). Therefore, these results suggest that NIRS could be applied for the rapid determination of the contents of caffeine, EGC, C, EGCG, EC, ECG, and total catechins in tea leaves for breeding programs that develop high-quality tea plants.
Assuntos
Camellia sinensis/química , Catequina/química , Extratos Vegetais/química , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Chá/química , Cafeína/análise , Folhas de Planta/químicaRESUMO
This study was aimed to determine the contents and the association of B vitamins from seeds of 10 black and one yellow soybean (Glycine max (L.) Merr.) varieties with either green or yellow cotyledon. Thiamine, flavin adenine dinucleotide (FAD), riboflavin and total riboflavin were found highest in 'Chengjakong', while flavin mononucleotide (FMN) was greatest in 'Mirang'. Nicotinic acid and total vitamin B3 were highest in 'Shingi' as a yellow soybean variety but pantothenic acid and pyridoxine contents were greatest in 'Tawon' and 'Mirang', respectively. These content variations of B vitamins directly reflected the wide segregation of soybean varieties on the principal component analysis (PCA) scores plot, indicating that these 4 soybean varieties appeared to be least associated with other soybean varieties based on the different responses of B vitamins. The results of cluster and correlation analyses presented that the cotyledon colour of soybean seed contributed to a variation of B vitamin contents. Overall, the results suggest that a wide range of B vitamin contents would be affected by genotypic factors alongside the difference of cotyledon colour.
Assuntos
Glycine max/química , Sementes/química , Complexo Vitamínico B/análise , Riboflavina/análise , Sementes/classificação , Glycine max/classificação , Tiamina/análiseRESUMO
The soybean seed is placed in the middle of the morphological and developmental alterations, such as changes in seed size, weight, and colour, and alteration of the composition and contents of metabolites during maturation. In this study, we used black soybean seeds to investigate the effect of maturity on metabolite levels at different maturity stages. Seeds were sorted into five maturity categories, from M1 to M5, based on seed size and external pigmentation. Maturity stages M1, M3, and M5 are equivalent to R6, R7, and R8 on the soybean reproductive growth stage scale, indicating full seed, beginning maturity, and full maturity, respectively. As seed maturation progressed, the seed size decreased and the water soluble extract changed, indicating that a change of seed pigmentation occurred. At the same time, numerous metabolites responded differentially to seed maturation. The partial least squares (PLS) scores plot indicated that the metabolic alteration during maturation was clearly visible. Furthermore, isoflavones were highly associated with seed maturity on the PLS loading plot while fatty acids, glucose, fructose, and sucrose were less linked with seed maturity, indicating that those metabolites responded less to seed maturation. Overall, the results indicate that each category of metabolites is mediated differentially during maturation in black soybean seeds.
Assuntos
Glycine max/metabolismo , Pigmentos Biológicos/metabolismo , Sementes/crescimento & desenvolvimento , Ácidos Graxos/análise , Ácidos Graxos/metabolismo , Isoflavonas/análise , Isoflavonas/metabolismo , Pigmentos Biológicos/análise , Sementes/química , Sementes/metabolismo , Glycine max/química , Glycine max/crescimento & desenvolvimentoRESUMO
The metabolic changes of lutein, ß-carotene and chlorophyll a during germination of the soybean (Glycine max (L.) Merr.) sprout varieties, 'Pungsannamulkong' and 'Bosug', have been studied. Seeds were germinated at 20 °C with 80% humidity in the darkness and sampled at 2 day intervals for 10 days. Partial least squares (PLS) scores plot showed that the responses of three metabolites during germination were linearly linked with each other except for day 2 in both varieties. PLS loading plots indicated that lutein content in whole sprout and cotyledon was closely associated with germination in 'Pungsannamulkong' while the chlorophyll a content in whole sprouts was highly linked with germination in 'Bosug'. Heatmap analyses revealed that lutein and ß-carotene levels, but not those of chlorophyll a, accumulated in whole soybean sprouts and cotyledon. While hypocotyls did not accumulate lipophilic pigments during germination, the accumulation of lutein and ß-carotene in the cotyledons was greater in 'Pungsannamulkong' than in 'Bosug' sprouts. In addition, the contents of lutein, ß-carotene and chlorophyll a increased from those in the seeds. Overall, the metabolic changes of lutein, ß-carotene and chlorophyll a during germination are affected not only by variety but also by organ type.
Assuntos
Clorofila/análise , Glycine max/química , Glycine max/metabolismo , Luteína/análise , Sementes/crescimento & desenvolvimento , beta Caroteno/análise , Clorofila/metabolismo , Clorofila A , Germinação , Luteína/metabolismo , Sementes/química , Sementes/metabolismo , Glycine max/crescimento & desenvolvimento , beta Caroteno/metabolismoRESUMO
The aim of the present research was to determine an optimal acid hydrolysis condition using drying oven and microwave assisted methods to estimate isoflavone contents by RP-HPLC in soybean. All isoflavone glucosides were completely converted to their aglycones at 120min for drying oven and 50min for microwave. Optimal extraction time of the highest isoflavone aglycone content after acid hydrolysis was achieved in 3h. These results indicated that the optimised hydrolysis and extraction conditions of isoflavones in soybean were: soybean (1g) hydrolysed by 10ml of 1N HCl at 100°C for 50min using microwave assisted acid hydrolysis method, and then 15ml of EtOH was added to the mixture which leaved alone for 3h at room temperature for complete extraction. Thus, microwave is an easy, consumed less time, and reliable acid hydrolysis method to estimate soybean isoflavones in comparison with drying oven method.
RESUMO
The objectives of the present study were to investigate anthocyanin profiles and their biological properties, including antioxidant, anticancer, and antiallergic, from the red petals of Korean edible rose (Rosa hybrida cv. Noblered). The acidic methanol extract of this species showed potent biological activities at a concentration of 50µg/mL. Its anthocyanins were characterised as cyanidin 3,5-di-O-glucoside and pelargonidin 3,5-di-O-glucoside using reversed-phase C18 column chromatography, NMR spectroscopy, and HPLC-DAD-ESI/MS analysis. Cyanidin 3,5-di-O-glucoside was the predominant constituent (375mg/100g), representing about 85% of total content. Cyanidin 3,5-di-O-glucoside exhibited good scavenging activity against DPPH radical with IC50 value of 55.2µg/mL; pelargonidin 3,5-di-O-glucoside showed potent anticancer effects against LNCap (human prostate cell line), ACHN (human renal cell line) and MOLT-4F (human leukaemia cell line) cell cultures, with IC50 values of 6.43, 18.3, and 6.78µg/mL, respectively. Antiallergic activities were only moderate.
RESUMO
Anti-inflammatory and antiproliferative activities of anthocyanidins and anthocyanin-rich black soybean seed coats were studied in HT-29 human colon adenocarcinoma cells and carcinogen-treated F344 rats, respectively. Cyanidin and delphinidin significantly inhibited cell growth at concentrations of >or=1 microM. Anthocyanidins suppressed cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) mRNAs in TPA-stimulated HT-29 cells. Both yellow and black soybean seed coat supplementation (10%, w/w) did not significantly reduce the number of aberrant crypt foci (ACF), although a modest decrease in the number of ACF was observed in animals fed soybean seed coats. The colonic COX-2 mRNA level was suppressed in rats fed both soybean seed coat diet. The plasma prostaglandin E 2 (PGE 2) level was reduced only in rats fed black soybean seed coats. No difference was observed in either colonic iNOS mRNA or plasma nitric oxide level. These results indicate that anthocyanidins are possible anti-inflammatory agents; however, further studies are required to determine required intake levels in vivo to exert antitumor effect.
Assuntos
Antocianinas/administração & dosagem , Anti-Inflamatórios/administração & dosagem , Anticarcinógenos/administração & dosagem , Divisão Celular/efeitos dos fármacos , Glycine max/química , Sementes/química , Animais , Ciclo-Oxigenase 2/genética , Dieta , Dinoprostona/sangue , Células HT29 , Humanos , Masculino , Óxido Nítrico Sintase Tipo II/genética , RNA Mensageiro/análise , Ratos , Ratos Endogâmicos F344 , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
The MYB transcription factors play important roles in the regulation of many secondary metabolites at the transcriptional level. We evaluated the possible roles of the Arabidopsis R2R3-MYB transcription factors in flavonoid biosynthesis because they are induced by UV-B irradiation but their associated phenotypes are largely unexplored. We isolated their genes by RACE-PCR, and performed transgenic approach and metabolite analyses in lettuce (Lactuca sativa). We found that one member of this protein family, AtMYB60, inhibits anthocyanin biosynthesis in the lettuce plant. Wild-type lettuce normally accumulates anthocyanin, predominantly cyanidin and traces of delphinidin, and develops a red pigmentation. However, the production and accumulation of anthocyanin pigments in AtMYB60-overexpressing lettuce was inhibited. Using RT-PCR analysis, we also identified the complete absence or reduction of dihydroflavonol 4-reductase (DFR) transcripts in AtMYB60- overexpressing lettuce (AtMYB60-117 and AtMYB60-112 lines). The correlation between the overexpression of AtMYB60 and the inhibition of anthocyanin accumulation suggests that the transcription factorAtMYB60 controls anthocyanin biosynthesis in the lettuce leaf. Clarification of the roles of the AtMYB60 transcription factor will facilitate further studies and provide genetic tools to better understand the regulation in plants of the genes controlled by the MYB-type transcription factors. Furthermore, the characterization of AtMYB60 has implications for the development of new varieties of lettuce and other commercially important plants with metabolic engineering approaches.
Assuntos
Antocianinas/biossíntese , Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Lactuca/genética , Lactuca/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Fatores de Transcrição/metabolismo , Oxirredutases do Álcool/metabolismo , Sequência de Aminoácidos , Clonagem Molecular , Dados de Sequência Molecular , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Alinhamento de Sequência , Transcrição GênicaRESUMO
Molecular analysis of gene expression differences between green and red lettuce leaves was performed using the SSH method. BlastX comparisons of subtractive expressed sequence tags (ESTs) indicated that 7.6% of clones encoded enzymes involved in secondary metabolism. Such clones had a particularly high abundance of flavonoid-metabolism proteins (6.5%). Following SSH, 566 clones were rescreened for differential gene expression using dot-blot hybridization. Of these, 53 were found to overexpressed during red coloration. The up-regulated expression of six genes was confirmed by Northern blot analyses. The expression of chalcone synthase (CHS), flavanone 3-hydroxylase (F3H), and dihydroflavonol 4-reductase (DFR) genes showed a positive correlation with anthocyanin accumulation in UV-B-irradiated lettuce leaves; flavonoid 3',5'-hydroxylase (F3',5'H) and anthocyanidin synthase (ANS) were expressed continuously in both samples. These results indicated that the genes CHS, F3H, and DFR coincided with increases in anthocyanin accumulation during the red coloration of lettuce leaves. This study show a relationship between red coloration and the expression of up-regulated genes in lettuce. The subtractive cDNA library and EST database described in this study represent a valuable resource for further research for secondary metabolism in the vegetable crops.