Mature Red Fruits Research Articles

Natural variation in folate levels among tomato (Solanum lycopersicum) accessions

Folate content was estimated in tomato (Solanum lycopersicum) accessions using microbiological assay (MA) and by LC-MS. The MA revealed that in red-ripe fruits folate levels ranged from 4 to 60μg/100g fresh weight. The LC-MS estimation of red-ripe fruits detected three folate forms, 5-CH3-THF, 5-CHO-THF, 5,10-CH+THF and folate levels ranged from 14 to 46μg/100g fresh weight. In mature green and red ripe fruit, 5-CH3-THF was the most abundant folate form. Comparison of LC-MS with MA revealed that MA inaccurately estimates folate levels. The accumulation of folate forms and their distribution varied among accessions. The single nucleotide polymorphism was examined in the key genes of the folate pathway to understand its linkage with folate levels. Despite the significant variation in folate levels among tomato accessions, little polymorphism was found in folate biosynthesis genes. Our results indicate that variation in folate level is governed by a more complex regulation at cellular homeostasis level.

FT-IR and FT-Raman characterization of non-cellulosic polysaccharides fractions isolated from plant cell wall

The purpose of this work was to reveal the structural changes of cell wall polysaccharides’ fractions during tomato fruit development by analysis of spectral data. Mature green and red ripe tomato fruit were taken into consideration. The FT-IR spectra of water soluble pectin (WSP), imidazole soluble pectin (ISP) and diluted alkali soluble pectin (DASP) contained bands typical for pectins. Whereas for KOH fraction spectra bands typical for hemicelluloses were present. The FT-IR spectra showed the drop down of esterification degree of WSP and ISP polysaccharides during maturation. The changes in polysaccharides structure revealed by spectra were the most visible in the case of pectic polysaccharides. The WSP and DASP fraction pectins molecules length were shortened during tomato maturation and ripening. Whereas the ISP fraction spectra analysis showed that this fraction contained rhamnogalacturonan I, but also for red ripe was rich in pectic galactan comparing with ISP fraction from mature green.

EVALUATION OF FREE RADICAL SCAVENGING ACTIVITY AND CHEMICAL QUALITY OF MULBERRY FRUIT CULTIVARS 'CHIANG MAI' AND 'BURIRAM 60'

Mulberry fruit is high in nutritional content. This study compared the radical scavenging activity and chemical quality of two mulberry cultivars, ‘Chiang Mai’ and ‘Buriram 60’, at different stages of harvest maturity. Mature green, pink, red and black fruit were used. Results showed that antioxidant activity based on DPPH assay was higher in red and black fruit of both cultivars than other maturity stages. Total soluble solids, citric, malic and tartaric acid decreased with increasing maturity. On the other hand, pH, total phenolic and anthocyanin increased with maturity. The results provide benchmark data for the exploitation of mulberry fruit for functional food and nutraceutical purposes.

Resistances to anthracnose (Colletotrichum acutatum) of Capsicum mature green and ripe fruit are controlled by a major dominant cluster of QTLs on chromosome P5

Anthracnose (Colletotrichum spp.) is a serious disease worldwide in pepper (Capsicum) production. Inheritance of resistance to Colletotrichum acutatum from a Capsicum chinense accession (PBC932) was studied in a BC1 population derived from a hybrid with Capsicum annuum line 77013 (susceptible) using a QTL analysis method. Resistance test was performed on detached mature green and mature red fruit under laboratory conditions by evaluated in disease incidence, true lesion diameter and overall lesion diameter. Based on a linkage map with 14 linkage groups, 385 markers (SSR, InDel and CAPS), 1310.2cM in length, inclusive Composite Interval Mapping (ICIM) revealed main effect QTLs located in a close marker interval on P5 chromosome for all fruit stages and resistance criteria, and four minor-effect QTLs only at green mature stage. Identification of recombinant individuals suggested that resistance in green versus red fruit may be controlled by distinct genes within the QTL interval on P5.

Changes in Antioxidant Activity of Cyphomandra betacea (Cav.) Sendtn. Fruits During Maturation and Senescence

Antioxidants are extremely important substances that possess the ability to protect the body from damage caused by free radical induced oxidative stress. Antioxidants are derived from dietary sources, such as fruits, vegetables, and beverages. In this study, the antioxidant activity of different maturity stages of two varieties of Cyphomandra betacea fruits of Darjeeling was evaluated in vitro. The radical scavenging properties on 2,2-diphenyl-1-picrylhydrazyl, superoxide anion, hydroxyl radical, lipid peroxidation, nitric oxide, and reducing power as well as the flavonoids, phenolics, lycopene, and total carotene contents of methanolic extracts of the fruits were determined. All fruit extracts, mainly the mature red fruit of purple-red variety exhibited strong scavenging activity towards all radicals tested due to the presence of relatively high total phenol, flavonoids, and lycopene as well as total carotene contents. The findings suggest that purple red variety of C. betacea fruit is endowed with antioxidant phytochemicals, which could provide protection against oxidative stress induced diseases.

Suppression of γ-Aminobutyric Acid (GABA) Transaminases Induces Prominent GABA Accumulation, Dwarfism and Infertility in the Tomato (Solanum lycopersicum L.)

Tomatoes accumulate γ-aminobutyric acid (GABA) at high levels in the immature fruits. GABA is rapidly converted to succinate during fruit ripening through the activities of GABA transaminase (GABA-T) and succinate semialdehyde dehydrogenase (SSADH). Although three genes encoding GABA-T and both pyruvate- and α-ketoglutarate-dependent GABA-T activities have been detected in tomato fruits, the mechanism underlying the GABA-T-mediated conversion of GABA has not been fully understood. In this work, we conducted loss-of-function analyses utilizing RNA interference (RNAi) transgenic plants with suppressed pyruvate- and glyoxylate-dependent GABA-T gene expression to clarify which GABA-T isoforms are essential for its function. The RNAi plants with suppressed SlGABA-T gene expression, particularly SlGABA-T1, showed severe dwarfism and infertility. SlGABA-T1 expression was inversely associated with GABA levels in the fruit at the red ripe stage. The GABA contents in 35S::SlGABA-T1(RNAi) lines were 1.3-2.0 times and 6.8-9.2 times higher in mature green and red ripe fruits, respectively, than the contents in wild-type fruits. In addition, SlGABA-T1 expression was strongly suppressed in the GABA-accumulating lines. These results indicate that pyruvate- and glyoxylate-dependent GABA-T is the essential isoform for GABA metabolism in tomato plants and that GABA-T1 primarily contributes to GABA reduction in the ripening fruits.

Determination of a colour index for fruit of pomegranate varietal group “Mollar de Elche”

Pomegranate acceptability by consumers and processors depends basically on a combination of several quality attributes, among them rind colour, sugar content, acidity and flavour. The pomegranate varietal group “Mollar de Elche” is one of the most highly valued worldwide because of its outstanding flavour and high antioxidant content. The aim of this study was to determine how the external colour of the fruit evolves from the young state to harvesting, focusing on obtaining a maturity index to provide growers with a cheap, rapid and non-destructive way of assessing the optimal time for harvesting. The colorimetric maturity index (MIc) proposed, which integrates the three colorimetric coordinates, L*, a* and b*, shows very little interannual variability. It also shows a high degree of correlation with the number of days elapsing since the beginning of fruit development, with fruit growth and with the chemical maturity index, permitting the period of fruit growth and ripening to be divided into four phases running from the beginning of fruit development (MIc<−20, immature very green fruit) until the time when fruit are ready for harvest (MIc>25, mature reddish yellow or red fruit).The index proved to be robust, with little interannual variability and a high degree of correlation with the number of days since the beginning of fruit development, fruit growth and the evolution of the chemical maturity index, permitting growers to determine cheaply, non-destructively and objectively the optimal moment for harvesting the varietal group “Mollar de Elche”.

Physicochemical and Sensory Characteristics of Arabic Gum-Coated Tomato (Solanum Lycopersicum L.) Fruits during Storage

The effects of gum arabic surface coating (5–20% aqueous gum solution) on physicochemical and sensory properties of mature red tomato fruits during 16 days of storage at 10 ± 1C were investigated. The firmness of uncoated fruits was significantly (P ≤ 0.05) lower, while weight loss was higher than coated ones. Uncoated tomatoes had higher total soluble solids, low acidity and fluctuating pH values. The values of L and b of the fruits decreased, while that of a increased during storage. The hue angle of the fruits significantly decreased, but total color change significantly increased during storage. The chroma and browning index of fruits increased slightly, while the color index increased significantly. Gum coating showed a better retention of all these physical, chemical and optical parameters of stored tomatoes. Panelists' results showed that gum-coated tomato fruits have acceptable sensory quality. Practical Applications Tomato is an important food commodity from nutritional and commercial point of view; however, freshly harvested tomato fruits have shorter shelf life in the market. Strategies to preserve its physicochemical and sensorial characteristics have significance for grower, processor and seller. We observed that gum arabic coating effectively preserved different quality attributes of tomato fruits for 16 days while stored at even more than normal refrigeration temperature. Our findings are valuable for those involved in tomato fruit handling and processing.

Isolation, identification and dyeing studies of betanin on modified acrylic fabrics

Mature red fruits of Opuntia ficus-indica contain two soluble pigment, betanin and indicaxanthin. The optimal conditions for dye extraction were to mix 50g of juice from cactus pears with 100mL of acidified water as solvent for dye extraction. Two main dyes were purified from the pigment extract by chromatography and identified by UV–vis, HPLC and LC–MS techniques as indicaxanthin (15mg per 100g) and betanin (280mg per 100g). The effect of dye bath pH, salt concentration, dyeing time and temperature was studied. The optimal conditions for dyeing modified acrylic fabrics with betanin dye were carried out at 50°C for 45min at pH 5. Un-mordanted samples have good properties of water and washing fastness. Mordant CoSO4 was found to give good light fastness (rating 5).

Parasitoides Asociados aAnthonomus sisyphusClark (Coleoptera: Curculionidae) en Frutos de Nanche Rojo (Malpighia mexicana) en Oaxaca, México

Malpighia mexicana, or red nanche, is a plant with edible fruits, used on crafts and medicine, as well as for the establishment of living fences. The objective of this work was to catalog the parasitoids associated with Anthonomus sisyphus Clark (Coleoptera: Curculionidae) in the fruit of M. mexicana in the central valleys of Oaxaca, México. The sampling sites were located in San Lorenzo Cacaotepec and the Ethnobotanical Garden of Santo Domingo. From 2005 to 2007, mature red nanche fruits were collected weekly to determine the emergency of the parasitoids. The fruits were weighed, counted and placed in trays. The greatest infestation was found in San Lorenzo Cacaotepec with 1.16 to 1.44 weevils per fruit while in the Ethnobotanical Garden were 0.74 to 1.18 weevils per fruit. Seven different species of parasitoids belonging to the families Braconidae, Pteromalidae, and Eupelmidae were found associated with A. sisyphus. The most abundant species were Triaspis eugenii, Diospilus sp., and Bracon sp. The Ethnobotanical Garden was the site with the greatest abundance of species of parasitoids and presented the highest level of parasitism. The species with the highest proportion of males were Bracon sp. in 2005 and 2007 and T. eugenii in 2006.

Constitutively expressed DHAR and MDHAR influence fruit, but not foliar ascorbate levels in tomato

Vitamin C (L-ascorbate, AsA) is an essential nutrient required in key metabolic functions in humans and must be obtained from the diet, mainly from fruits and vegetables. Given its importance in human health and plant physiology we sought to examine the role of the ascorbate recycling enzymes monodehydroascorbate reductase (MDHAR) and dehydroascorbate reductase (DHAR) in tomato (Solanum lycopersicum), an economically important fruit crop. Cytosolic-targeted tomato genes Mdhar and Dhar were cloned and over-expressed under a constitutive promoter in tomato var. Micro-Tom. Lines with increased protein levels and enzymatic activity were identified and examined. Mature green and red ripe fruit from DHAR over-expressing lines had a 1.6 fold increase in AsA content in plants grown under relatively low light conditions (150 μmol m(-2) s(-1)). Conversely, MDHAR over-expressers had significantly reduced AsA levels in mature green fruits by 0.7 fold. Neither over-expressing line had altered levels of AsA in foliar tissues. These results underscore a complex regulation of the AsA pool size in tomato.

First Report of Fusarium solani Causing Fruit Rot of Sweet Pepper in Trinidad.

In Trinidad, sweet pepper (Capsicum annuum L.) is an important crop that is produced for local markets and regional export. From February to April 2010, severe fruit rot was observed in 9 of 11 commercial fields located in North Trinidad in the major production areas of North and South Aranguez. All fields were in the late harvesting stage and the most commonly grown cultivars were Aristotle and Canape. Disease incidence for each field was estimated to be 80% with a yield loss of 40 to 60%. Symptoms appeared on mature red fruits but growers reported that disease can also occur on green fruit. Symptoms began as soft lesions that turned dark brown to black. Lesions usually originated at the calyx end of the fruit and extended down the sides. Fruits were surface sterilized by rinsing with 70% ethanol for 2 min, followed by three rinses with sterile distilled water. Two 4-mm3 blocks of tissue from the opposite sides of fruit lesions were transferred to water agar and incubated for 5 to 7 days at 25 ± 1°C. A 4-mm3 agar block consisting of the leading mycelial edge was then transferred to potato dextrose agar (PDA) and incubated under the same conditions. Colonies on PDA were fast growing with white, fluffy, aerial mycelia; hyphae were septate and hyaline; conidiophores were unbranched; microconidia were abundant, thin walled, hyaline, ovoid, one to two celled, and measured 6 to 10 × 2 to 4 μm. Macroconidia were hyaline, three to four celled, curved, thick walled, and measured 20 to 30 × 4 to 6 μm. PCR amplification was carried out utilizing universal primers ITS4/5 and translation elongation factor primers EF1/2 (2). Sequence comparisons of the internal transcribed spacer (ITS) region (HM157262) and EF-1α gene (HQ014854) with cognate sequences available in GenBank and the FUSARIUM-ID databases revealed 100 and 99.6% sequence identity, respectively, to Fusarium solani (Mart.) Sacc. Pathogenicity tests were conducted by drop inoculating 10-μl of spore suspension (106 spores/ml) of each of four isolates on wounded and unwounded sites of mature sweet pepper fruits (five per isolate of cvs. Aristotle, Canape, Century, Destra, and Paladin). Control fruits were inoculated with sterile distilled water. Inoculated fruits were kept at 25 ± 1°C in loosely sealed plastic containers and monitored for the onset of symptoms for 6 days. The experiment was conducted twice. Lesions (8.0 to 15.2 mm in diameter) developed on wounded fruit of Aristotle, Canape, and Century. No symptoms were seen on Destra, Paladin, or the water controls. No symptoms developed on nonwounded fruits. Koch's postulates were fulfilled by reisolating the pathogen from infected tissues. Fruit rot caused by F. solani has been reported to be a serious constraint to sweet pepper production in Canada (4), the United Kingdom (1), and New Zealand (3). To our knowledge, this is the first report of Fusarium fruit rot of sweet pepper in Trinidad.

Study of the suitability of HRMAS NMR for metabolic profiling of tomatoes: Application to tissue differentiation and fruit ripening

The feasibility of HRMAS NMR as an efficient technique for metabolic studies of tomato fruit and tomato tissues is described. A good-taste tomato variety from Almería (Spain) (commercial name Zayno) was chosen for this study. Fruits of three different ripening stages (green, turning and red) were selected, based on their external appearance. NMR data of whole fruits were obtained through 1H HRMAS NMR spectra of tomato purée. Flesh, peel and seeds from mature red fruits were separately analysed. 1H HRMAS NMR spectra showed resolutions similar to that of solution 1H NMR with the advantages of minimal sample manipulation and possibility of analysing polar and non-polar compounds simultaneously. Seeds could be clearly distinguished by visual comparison of the spectra. Tryacylglycerols, in which linoleic (47%) and oleic (28%) acyl chains preponderate, were the major components of seeds. By contrast, signals of fructose, glucose, citric acid, and the amino acids GABA, glutamine and glutamate dominated the spectra of flesh, peel and tomato purée. Principal components analysis, performed on the covariance matrix, revealed a clear separation between peel and flesh. Apart form the presence of the cutin biopolymer, peel showed a specific accumulation of sugar and sugar moieties related to pectin degradation, as well as glycosylated metabolites. Chemometric analysis also allowed the metabolic trajectory from green to red mature stages to be visualised. However, sample heterogeneity in the analysis of the whole fruit proved to be an important issue. The source of such heterogeneity was assigned to the presence of tissues of different hardness in the small amount of sample used. The presence of two clusters of samples at the turning stage indicated that the levels of certain metabolites could diverge significantly in fruits with almost identical appearance.

α-Mannosidase Involved in Turnover of Plant Complex TypeN-Glycans in Tomato (Lycopersicum esculentum) Fruits

In this study, we purified and characterized an alpha-mannosidase to homogeneity from mature red tomato fruits. Purified alpha-mannosidase (alpha-Man LE-1) gave two separate bands, of molecular masses of 70 kDa (L-subunit) and 47 kDa (S-subunit), on SDS-PAGE under non-reducing and reducing conditions. On the other hand, the molecular weight was estimated to be 230 kDa by gel filtration, indicating that alpha-Man LE-1 functions in a tetrameric structure in plant cells. The N-terminal sequence of the L-subunit and the S-subunit were determined to be L-Y-M-V-Y-M-T-K-Q-G- and X-X-L-E-Q/K-S-F-S-Y-Y respectively. When pyridylaminated N-glycans were used as substrates, alpha-Man LE-1 showed optimum activity at about pH 6 and at 40 degrees C, and the activity was completely inhibited by both swainsonine and 1-deoxy-mannojirimycin. alpha-Man LE-1 hydrolyzed the alpha-mannosidic linkages from both high-mannose type and plant complex type N-glycan, but preferred a truncated plant complex type structure to high-mannose type N-glycans bearing alpha1-2 mannosyl residues.

In Planta Transformation of Tomato

In this study, in planta transformation of tomato (Solanum lycopersicum L.), using fruit injection and floral dip, is reported. Agrobacterium tumefaciens strain EHA 105 containing one of three constructs, i.e., pROKIIAP1GUSint (carrying the Apetala 1 [AP1] gene), pROKIILFYGUSint (carrying the LEAFY [LFY] gene), or p35SGUSint (carrying the β-glucuronidase [GUS] gene), was used for plant transformation. For fruit injection transformation, no significant effects (p > 0.05) of the construct used were observed. The highest frequency of transformation was obtained following 48-h incubation of tomato fruit with bacterial cells harboring either one of the three constructs; transformation frequencies of 17%, 19%, and 21% for AP1, LFY, and GUS gene constructs, respectively, were obtained. When fruit maturity was evaluated in fruit injection experiments, mature red fruit resulted in higher frequency of transformants than immature green fruit with 40%, 35%, and 42% for AP1, LFY, and GUS gene constructs, respectively. For floral dip transformation, a higher number of transformants was obtained when the GUS gene construct was used instead of either the AP1 or LFY gene construct, thus suggesting a possible inhibitory effect of the flowering genes used. When flowers were transformed prior to rather than following pollination, they yielded a higher transformation frequency, 12% for the LFY construct and 23% for the GUS construct (p < 0.05), although no transformant was obtained with the AP1 gene construct. All putative GUS-positive transformants were analyzed using polymerase chain reaction and confirmed for the presence of the transgene. Compared to control plants, transgenic plants carrying either the AP1 or LFY transgene flowered earlier and showed several different morphological characters.

Changes in ascorbic acid concentration, ascorbate oxidase activity, and apoplastic pH in relation to fruit development in pepper (Capsicum annuum L.) and the occurrence of blossom-end rot

SummaryWe recently suggested that the occurrence of ascorbic acid (AsA) in the apoplast of bell pepper fruit may be part of the protection mechanism against blossom-end rot (BER). In the present study, we determined AsA concentrations, changes in pH, and the activities of ascorbate oxidase (AO) in the apoplast and symplast of pepper fruit, in relation to fruit development and the occurrence of BER. In healthy pepper fruit, the concentrations of AsA in the symplast and apoplast increased during fruit development, whereas the activity of AO decreased when measured at the pH typical of each developmental stage. The apoplastic pH decreased from 6.2 in young fruit to 4.8 in mature red fruit; while the symplastic pH did not change during fruit development. Following high-temperature treatment (35°C for 48 h in the dark), the concentration of apoplastic AsA, and the activity of galacturonic acid reductase (which participates in the AsA biosynthetic pathway), decreased, while there was an increase in apoplastic pH. The AsA content decreased in the apoplast of BER-affected fruit, and the pH was more alkaline (pH 6.9) than in healthy fruit (pH 6.0). In young fruit with BER, the apoplastic AO activity increased and the symplastic galacturonic acid reductase activity was inhibited. We suggest that a reduction in apoplastic AsA concentration, an increase in apoplastic AO activity, and changes in apoplastic pH in fruit prone to BER may be part of the mechanism which leads to the occurrence of BER symptoms. Whether or not there are causal relationships between these changes is not yet clear.

Biomechanics of isolated tomato (Solanum lycopersicum L.) fruit cuticles: the role of the cutin matrix and polysaccharides

The mechanical characteristics of the cuticular membrane (CM), a complex composite biopolymer basically composed of a cutin matrix, waxes, and hydrolysable polysaccharides, have been described previously. The biomechanical behaviour and quantitative contribution of cutin and polysaccharides have been investigated here using as experimental material mature green and red ripe tomato fruits. Treatment of isolated CM with anhydrous hydrogen fluoride in pyridine allowed the selective elimination of polysaccharides attached to or incrusted into the cutin matrix. Cutin samples showed a drastic decrease in elastic modulus and stiffness (up to 92%) compared with CM, which clearly indicates that polysaccharides incorporated into the cutin matrix are responsible for the elastic modulus, stiffness, and the linear elastic behaviour of the whole cuticle. Reciprocally, the viscoelastic behaviour of CM (low elastic modulus and high strain values) can be assigned to the cutin. These results applied both to mature green and red ripe CM. Cutin elastic modulus, independently of the degree of temperature and hydration, was always significantly higher for the ripe than for the green samples while strain was lower; the amount of phenolics in the cutin network are the main candidates to explain the increased rigidity from mature green to red ripe cutin. The polysaccharide families isolated from CM were pectin, hemicellulose, and cellulose, the main polymers associated with the plant cell wall. The three types of polysaccharides were present in similar amounts in CM from mature green and red ripe tomatoes. Physical techniques such as X-ray diffraction and Raman spectroscopy indicated that the polysaccharide fibres were mainly randomly oriented. A tomato fruit CM scenario at the supramolecular level that could explain the observed CM biomechanical properties is presented and discussed.

Identification of an Allele Attributable to Formation of Cucumber-like Flavor in Wild Tomato Species (Solanum pennellii) That Was Inactivated during Domestication

Carbon 6 (C6)-aldehydes formed by fatty acid 13-hydroperoxide lyase (13HPL) specific to fatty acid 13-hydroperoxides (13-HPO) are important flavor constituents in fresh tomato fruits. C9-aldehydes are usually formed by 9/13HPL showing dual specificity to 9- and 13-HPOs and are scarcely found in tomato fruits. Mature red fruits of one of the introgression lines, IL1-4, generated by hybridization of a cultivated tomato (Solanum lycopersicon) to its wild relative Solanum pennellii, form high amounts of C9-aldehydes upon homogenization. The IL1-4 fruits showed high 9/13HPL activity. One of the genes isolated from IL1-4 showed a high similarity to plant 9/13HPLs. Recombinant proteins expressed in Escherichia coli showed 9/13HPL activity. Cleaved amplified polymorphic sequence analyses indicated that the gene was specific to IL1-4 and S. pennellii. S. lycopersicon had a gene having high similarity to the S. pennellii gene. It was absent in IL1-4. Among the differences of amino acid residues found between the two genes, a Cys to Ser exchange may be responsible for the inactivation of resultant protein product of S. lycopersicon gene because the Cys is an essential amino acid residue for HPL activity. From these observations, it could be assumed that a tomato gene corresponding to S. pennellii 9/13HPL gene had been inactivated through domestication of tomatoes.

Environmental stresses activate a tomato SNF1-related protein kinase 2 homolog, SlSnRK2C

We isolated an SNF1-related kinase 2 homolog (SlSnRK2C) from tomato (Solanum lycopersicum L. cv. Micro-Tom) which has significant similarlity to AtSRK2C (72% amino acid identity). We profiled expression levels and biochemical properties of SlSnRK2C. In contrast to AtSRK2C which phosphorylates histone H1 and is mainly expressed in root chip, SlSnRK2C phosphorylates myelin basic protein but not histone H1 and SlSnRK2C mRNA is expressed in leaves, flowers and fruits but not in roots. Immunoblot by anti-SlSnRK2C-COOH terminus specific antiserum shows that SlSnRK2C is expressed remarkably in developing fruits, and weakly in flowers, mature green fruits and shoots, but marginally in mature red fruits or roots. SlSnRK2C is stimulated strongly by chilling and NaCl stress. These observations suggests that SlSnRK2C is possibly involved in fruit development and stress signaling in response to salt and chiling stress.

Fruit size and stage of ripeness affect postharvest water loss in bell pepper fruit (Capsicum annuum L.)

AbstractQuality of bell peppers after harvest is largely influenced by water loss from the fruit. The objective of this study was to determine the effect of fruit fresh weight, size, and stage of ripeness on the rate of water loss and permeance to water vapor. Fruit diameter was correlated with fresh weight, and surface area was associated with fresh weight and diameter. Fruit surface area decreased logarithmically with increases in fruit size, with smaller fruit showing larger changes in surface area than larger fruit. Mean water loss rate for individual fruit and permeance to water vapor declined with increases in fruit size and as fruit ripeness progressed. Fruit surface area/fresh weight ratio and rate of water loss were both highest in immature fruit and showed no differences between mature green and red fruit. In mature fruit, permeance to water vapor for the skin and calyx were 29 µmol m−2 s−1 kPa−1 and 398 µmol m−2 s−1 kPa−1, respectively. About 26% of the water loss in mature fruit occurred through the calyx. There was a decline in firmness, water loss rate, and permeance to water vapor of the fruit with increasing fruit water loss during storage. Copyright © 2006 Society of Chemical Industry