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At least 343 records · Page 19Linked to original sources
PubMed2003

Light-dark regulation of carotenoid biosynthesis in pepper (Capsicum annuum) leaves.

The carotenoid content in photosynthetic plant tissue reflects a steady state value resulting from permanent biosynthesis and concurrent photo-oxidation. The contributions of both reactions were determined in illuminated pepper leaves. The amount of carotenoids provided by biosynthesis were quantified by the accumulation of the colourless carotenoid phytoene in the presence of the inhibitor norflurazon. When applied, substantial amounts of this rather photo-stable intermediate were formed in the light. However, carotenoid biosynthesis was completely stalled in darkness. This switch off in the absence of light is related to the presence of very low messenger levels of the phytoene synthase gene, psy and the phytoene desaturase gene, pds. Other carotenogenic genes, such as zds, ptox and Icy-b also were shown to be down-regulated to some extent. By comparison of the carotenoid concentration before and after transfer of plants to increasing light intensities and accounting for the contribution of biosynthesis, the rate of photo-oxidation was estimated for pepper leaves. It could be demonstrated that light-independent degradation or conversion of carotenoids e.g. to abscisic acid is a minor process.

Capsicum↗
PubMed2003

Putrescine facilitated enhancement of capsaicin production in cell suspension cultures of Capsicum frutescens.

Putrescine treatment (0.1 mmol/L) influenced enhancement of growth and capsaicin production in the cell suspension cultures of C. frutescens. The administration of polyamine inhibitor DFMA (alpha-DL-difluoromethylarginine) resulted in a reduction of the growth, capsaicin content and the endogenous titres of polyamines (PAs). The capsaicin synthase activity was also higher in the putrescine (Put) treated cultures. Ethylene levels were lower in the cultures treated with putrescine. This study suggested that Put facilitates growth and capsaicin production.

Capsaicin↗
PubMed2001

Aflatoxins B1 in different grades of chillies (Capsicum annum L.) in India as determined by indirect competitive-ELISA.

Samples of the three grades of chilli pod (grades 1 to 3) were collected during surveys in 1998 and 1999 from the principal market yards and cold storage facilities of the major chilli-growing areas of Andhra Pradesh (AP), India. Chilli powders were collected from different supermarkets in Hyderabad, AP. They were analysed for aflatoxin B1 (AFB1) content by an indirect competitive ELISA. To avoid the influence of interfering substances present in chilli extracts, it was necessary to prepare the aflatoxin standards in methanol extracts of chillies free from aflatoxins. For nine representative samples there was good agreement between ELISA and HPLC estimations of AFB1 and the results suggested that the ELISA procedure adopted was dependable. Of the 182 chilli samples tested, 59% of the samples were contaminated with AFB1 and 18% contained the toxin at non-permissible levels. The highest AFB1 concentration of 969 microg/kg was found in one sample representing grade 3. Overall the maximum percentage of chilli pods showing AFB1 levels higher than 30 microg/kg (non-permissible levels) was in grade 3. Chilli pods stored in refrigerated rooms showed the lowest proportion of samples containing aflatoxin. Nearly 9% of the chilli powders sold in supermarkets contained non-permissible aflatoxin levels. This report highlights the importance of using grade 1 chilli pods to minimize aflatoxin contamination.

Aflatoxin B1↗
PubMed2003

The CaTin1 (Capsicum annuum TMV-induced clone 1) and CaTin1-2 genes are linked head-to-head and share a bidirectional promoter.

CaTin1 was expressed relatively early in the TMV-inoculated leaves of hot pepper which is resistant to TMV-P(0) infection. Interestingly, there was another homologous gene (CaTin1-2) located in front of CaTin1 in a head-to-head fashion and they shared a single promoter. The expression profile of the CaTin1-2 was very similar to CaTin1 in all the treatments except the slower induction time compared to CaTin1 upon TMV-P(0) inoculation. The promoter analysis of CaTin1 and CaTin1-2 revealed bidirectionality both in cis-elements and activity. The CaTin1-2 promoter had two TATA-boxes, four GCC-boxes, the root responsive element, and a W1-box. The ethylene-inducible promoter activity depended on GCC-boxes and TMV-inducible activity of the CaTin1-2 promoter reached its highest activity when this promoter had a W1-box.

Amino Acid Sequence↗
PubMed2003

Expression of peroxidase-like genes, H2O2 production, and peroxidase activity during the hypersensitive response to Xanthomonas campestris pv. vesicatoria in Capsicum annuum.

Pepper ascorbate peroxidase-like (CAPOA1), thioredoxin peroxidase-like (CAPOT1), and peroxidase-like (CAPO1) clones were isolated from pepper leaves inoculated with avirulent strain Bv5-4a of Xanthomonas campestris pv. vesicatoria. CAPOA1, CAPOT1, and CAPO1 mRNA disappeared 18 to 30 h after the bacterial infection when the hypersensitive response (HR) was visible. In contrast, peroxidase activity reached a peak at 18 h after infection and then declined at 24 and 30 h when H2O2 accumulation level was maximal. These results suggest that the striking accumulation of H2O2 and strong decrease in peroxidase activity during the programmed cell death may be due to the strong suppression of CAPOA1, CAPOT1, and CAPO1 gene expression. Infection by Phytophthora capsici or Colletotricum gloeosporioides also induced the expression of the three putative peroxidase genes in pepper tissues. CAPOA1 mRNAs were in situ localized in phloem areas of vascular bundles in pepper tissues infected by Colletotricum. coccodes, P. capsici, or C. gloeosporioides. Exogenous treatment with H2O2 strongly induced the CAPOA1 and CAPOT1 transcription 1 h after treatment, while the CAPO1 transcripts accumulated 12 h after H2O2 treatment. We suggest that pepper ascorbate peroxidase and thioredoxin peroxidase genes may function as regulators of H2O2 level and total peroxidase activity in the oxidative burst during the HR to incompatible pathogen interaction in pepper plant.

Amino Acid Sequence↗
PubMed2005

Molecular mapping of the chlorophyll retainer (cl) mutation in pepper (Capsicum spp.) and screening for candidate genes using tomato ESTs homologous to structural genes of the chlorophyll catabolism pathway.

The chlorophyll retainer (cl) mutation causes inhibition of chlorophyll degradation during pepper fruit ripening and is controlled by a single recessive gene. The retention of chlorophyll in mature red or yellow fruits produces brown- or green-colored ripe fruits, respectively. We mapped CL on chromosome 1 of pepper corresponding to chromosome 8 in tomato in which a homologous mutation, green flesh, was previously assigned. To test whether known structural genes from the chlorophyll catabolism pathway could correspond to CL, we mapped tomato expressed sequence tag clones corresponding to three loci of CHLOROPHYLLASE and one locus of PHEOPHORBIDE A OXYGENASE in the tomato introgression lines population. The three CHLOROPHYLLASE loci mapped to chromosomes 6, 9, and 12, while PHEOPHORBIDE A OXYGENASE mapped to chromosome 11, indicating that CL may correspond to an as yet unavailable gene from the chlorophyll catabolism pathway or to a regulator of the pathway.

Capsicum↗
PubMed2005

Construction of 2 intraspecific linkage maps and identification of resistance QTLs for Phytophthora capsici root-rot and foliar-blight diseases of pepper (Capsicum annuum L.).

Two linkage maps of pepper were constructed and used to identify quantitative trait loci (QTLs) conferring resistance to Phytophthora capsici. Inoculations were done with 7 isolates: 3 from Taiwan, 3 from California, and 1 from New Mexico. The first map was constructed from a set of recombinant inbred lines (RILs) of the PSP-11 (susceptible) x PI201234 (resistant) cross; and the second map was from a set of F(2) lines of the Joe E. Parker' (susceptible) x 'Criollo de Morelos 334' (resistant) cross. The RIL map covered 1466.1 cM of the pepper genome, and it consisted of 144 markers -- 91 amplified fragment length polymorphisms (AFLPs), 34 random amplified polymorphic DNA (RAPDs), 15 simple sequence repeats (SSRs), 1 sequence characterized amplified region (SCAR), and 3 morphological markers -- distributed over 17 linkage groups. The morphological markers mapped on this population were erect fruit habit (up), elongated fruit shape (fs(e)), and fasciculate fruit clusters (fa). The F(2) map consisted of 113 markers (51 AFLPs, 45 RAPDs, 14 SSRs, and 3 SCARs) distributed in 16 linkage groups, covering a total of 1089.2 cM of the pepper genome. Resistance to both root rot and foliar blight were evaluated in the RIL population using the 3 Taiwan isolates; the remaining isolates were used for the root-rot test only. Sixteen chromosomal regions of the RIL map contained single QTLs or clusters of resistance QTLs that had an effect on root rot and (or) foliar blight, revealing a complex set of genetics involved in resistance to P. capsici. Five QTLs were detected in the F(2) map that had an effect on resistance to root rot.

Analysis of Variance↗
PubMed1998

Bell peppers (Capsicum annuum) express allergens (profilin, pathogenesis-related protein P23 and Bet v 1) depending on the horticultural strain.

BACKGROUND: Little is known about the role of bell peppers in food allergy. We collected sera from 11 patients with food allergy to bell peppers to analyze bell pepper extracts for allergen composition. METHODS: Proteins of mature fruits of eight horticultural strains of bell peppers were extracted and tested with patients' sera for IgE binding and with monoclonal and polyclonal antibodies in immunoblot. RESULTS: Profilin was detected in bell pepper extracts by an anti-celery profilin antibody. It showed high IgE binding activity in all extracts, which could be inhibited by recombinant birch pollen profilin. Anti-birch pollen monoclonal antibody BIP3, directed against birch pollen proteins between 30 and 69 kD, bound to bell pepper antigens of comparable molecular weights. A homologue of the major birch pollen allergen Bet v 1 was detected in four of eight horticultural strains of bell peppers, and was shown to bind IgE in 1 of the 11 patients. A 23-kD allergen of bell peppers was shown to correspond to the 23-kD major paprika allergen by IgE absorption experiments. Its N-terminal sequence showed 100% identity to P23 from tomatoes. CONCLUSION: The appearance of profilin in all and Bet v 1 in 50% of the tested horticultural strains indicates that bell peppers have to be considered potentially dangerous for Bet v 1- and profilin-sensitized patients. Moreover, in 4 of 8 horticultural strains of bell peppers a homologue of the osmotin-like protein P23 from tomatoes is responsible for substantial IgE binding. Contact with Bet v 1 and P23 homologues in bell peppers can therefore be minimized by avoidance of the respective horticultural strains.

Adult↗
PubMed2003

Cloning and molecular and immunological characterisation of two new food allergens, Cap a 2 and Lyc e 1, profilins from bell pepper (Capsicum annuum) and Tomato (Lycopersicon esculentum).

BACKGROUND: Profilins are recognised by IgE of about 20% of patients allergic to birch pollen and plant foods. They are ubiquitous intracellular proteins highly cross-reactive among plant species. Therefore, they were called panallergens and are made responsible for cross-sensitisation between plant pollen and food. OBJECTIVES: The aim of the present study was to clone the cDNAs encoding profilins from bell pepper and tomato, to produce and purify the recombinant proteins and to compare their IgE-binding capacities to those of the natural proteins. METHODS: cDNA clones coding for profilin were obtained by RT-PCR from total RNA of tomato and bell pepper fruits, sequenced and expressed as non-fusion proteins in ESCHERICHIA COLI. The recombinant profilins were subsequently purified and tested for IgE-binding and inhibition capacity with sera from 34 food-allergic patients. Possible oligomerisation of recombinant profilins was investigated by HPLC analysis and its influence on IgE binding assayed by ELISA. RESULTS: The open reading frame from both profilins encompasses 393 bp with a predicted molecular mass of 14,184 kD and a pI of 4.44 for bell pepper profilin (Cap a 2) and 14,257 kD and a pI of 4.46 for the profilin from tomato (Lyc e 1). The two protein sequences display 91% identity, whereas tomato profilin from pollen shares only 75% identity with tomato fruit profilin. Eleven out of 34 food-allergic patients (32%) display IgE binding to both purified profilins. Preincubation of a serum pool with either purified rCap a 2 or rLyc e 1 nearly abolished IgE binding to natural Cap a 2 and Lyc e 1, respectively. In addition, purified recombinant Cap a 2 was able to inhibit IgE-binding to rLyc e 1 by approximately 50%, whereas rLyc e 1 completely blocked IgE-binding to rCap a 2 in cross-inhibition assays. HPLC analysis showed that in solution Cap a 2 and Lyc e 1 can be found predominantly as dimers, which can be partially reduced to monomers by addition of dithiothreitol (DTT). In ELISA DTT-treated Lyc e 1 displayed a clearly lower IgE-binding capacity than untreated profilin. CONCLUSIONS: Purified rCap a 2 and rLyc e 1 proved to be valuable tools for studying cross-reactivity to profilins in patients allergic to pollen and food.

Adolescent↗
PubMed2006

Honeybee interference as a novel aid to reduce pollen exposure and nasal symptoms among greenhouse workers allergic to sweet bell pepper (Capsicum annuum) pollen.

BACKGROUND: In 1999, an extensive study among bell pepper growers showed a prevalence of 53.8% work-related symptoms and 35.4% sensitisation to bell pepper pollen. Experiments with bees to remove pollen from bell pepper flowers have been done for a few years. OBJECTIVES: It was the aim of this study to investigate whether bees can reduce the pollen exposure in bell pepper greenhouses and whether this reduction results in a decrease in allergic complaints in the greenhouse workers. METHODS: Eighteen greenhouses were selected for the study. In each greenhouse, pollen exposure was estimated. In 6 and 3 of the greenhouses, high, respectively low, numbers of honeybees were placed throughout the pollen season of the sweet bell pepper plant. Nine greenhouses without honeybees were used as control. At baseline, as well as after 4 and 8 months, nasal symptoms assessed with a visual analogue score and lung function parameters were used as outcome measure. RESULTS: Forty-four of the 133 employees invited reported work-related symptoms. High numbers of bees reduced the pollen amount in a dose-dependent way to 18% of the baseline exposure. A significant trend relationship between the visual analogue scale in nasal symptoms and the number of colonies of bees was seen. CONCLUSIONS: The interference of bees in bell pepper greenhouses significantly reduces the pollen amount. This reduction is associated with less work-related rhinitis symptoms in allergic greenhouse workers. This intervention study supports the hypothesis that allergic work-related complaints of greenhouse workers, sensitised to bell pepper pollen, are caused by occupational exposure to this pollen in the greenhouse.

Adult↗
PubMed2006

Capsinoid is biosynthesized from phenylalanine and valine in a non-pungent pepper, Capsicum annuum L. cv. CH-19 sweet.

The biosynthetic pathway of capsinoid in 'CH-19 Sweet' was investigated. [(3)H]Valine and [(14)C]phenylalanine were injected into the fruits of the intact plant. Both of radioactivities were detected in capsinoid fractions. (14)C radioactivity was observed in phenylpropanoid compounds, and in vanillin, vanillylamine, vanillyl alcohol, and vanillic acid. We confirmed that capsinoid is biosynthesized from phenylalanine and valine.

Capsaicin↗
PubMedDate not supplied

Enzymatic hydrolysis of carotenoid fatty acid esters of red pepper (Capsicum annuum L.) by a lipase from Candida rugosa.

Analyses of red pepper extracts which had been pretreated with lipase type VII (EC 3.1.1.3.) from Candida rugosa showed for the first time pepper carotenoid esters to be substrates of this enzyme. However, the extent of enzymatic hydrolysis depends on the respective carotenoid and was not quantitative compared to chemical saponification. After enzymatic cleavage, 67-89% of total capsanthin, 61-65% of total zeaxanthin, 70-81% of total beta-cryptoxanthin and 70-86% of total violaxanthin were detected in free form. Nevertheless, the method described here offers the possibility to cleave in part several carotenoid esters originating from red pepper quickly and under comparatively mild reaction conditions. Replacement of the generally performed alkaline hydrolysis by enzymatic cleavage allows the resulting product to be used in food industry as "natural" coloring agent e.g. to colour cheese and jellies.

Candida↗