Characterization of the GGP gene family in potato (Solanum tuberosum L.) and Pepper (Capsicum annuum L.) and its expression analysis under hormonal and abiotic stresses.

GDP-L-galactose phosphorylase (GGP) is a key rate-limiting enzyme in plant ascorbic acid synthesis, which plays an important role in plant growth and development as well as stress response. However, the presence of GGP and its function in potato and pepper are not known. In this study, we first identified two GGP genes in each potato and pepper genomes using a genome-wide search approach. We then analyzed their physicochemical properties, conserved domains, protein structures and phylogenetic relationships. Phylogenetic tree analysis revealed that members of the potato and pepper GGP gene families are related to eggplant (Solanum melongena L.), Arabidopsis (Arabidopsis thaliana L.), tobacco (Nicotiana tabacum L.) and tomato (Solanum lycopersicum L.), with tomato being the most closely related. The promoter sequences mainly contain homeopathic elements such as light-responsive, hormone-responsive and stress-responsive, with light-responsive elements being the most abundant. By analyzing the structure of the genes, it was found that there is no transmembrane structure or signal peptide in the GGP gene family of potatoes and peppers, and that all of its members are hydrophilic proteins. The expression profiles of different tissues show that StGGP1 has the highest expression levels in leaves, StGGP2 has the highest expression levels in stamens, and CaGGPs have the highest expression levels in the early stages of fruit development (Dev1). It was found that StGGPs and CaGGPs genes showed different response to phytohormones and abiotic stresses. Abscisic acid (ABA) treatment induced the most significant change in the expression of StGGPs, while the expression of CaGGPs showed the most pronounced change under methyl jasmonate (MeJA) treatment. StGGPs responded mainly to dark treatment, whereas CaGGPs responded mainly to NaCl stress. These results provide an important basis for a detailed study about the functions of GGP homologous genes in potato and pepper in response to abiotic stresses.

Melatonin Combined with Wax Treatment Enhances Tolerance to Chilling Injury in Red Bell Pepper.

Bell peppers (Capsicum annuum L.) are prone to chilling injury (CI) when stored at temperatures below 7 °C. Melatonin, a natural plant regulator, plays a critical role in defending against different pre- and post-harvest abiotic stresses, including those associated with cold storage. This study aimed to assess the effects of applying exogenous melatonin alone and in combination with a commercial wax on the CI tolerance, postharvest life, and potential biomarker search of red bell peppers. In the initial experiment, the effective melatonin concentration to reduce CI effects was determined. Peppers were sprayed with either distilled water (control) or a melatonin aqueous solution (M100 = 100 µM or M500 = 500 µM) and then stored for 33 d at 4 °C, followed by 2 d at 20 °C. The M500 treatment proved to be more effective in reducing fruit CI incidence (superficial scalds) and metabolic rate, while weight loss, softening, and color were comparable to the control. A second experiment assessed the potential synergistic effects of a combined melatonin and commercial wax treatment on pepper CI and quality. Fruits were sprayed with distilled water (control), melatonin (M500), commercial wax (Wax), or the combined treatment (Wax + M500) and stored for 28 d at 4 °C, followed by 2 d at 20 °C. The Wax + M500 was the most effective in significantly reducing the incidence of fruit CI symptoms and calyx fungal infection. Furthermore, this combined treatment enhanced fruit weight loss prevention compared with individual melatonin or wax treatment. Also, Wax + M500-treated peppers exhibited notable proline accumulation, indicative of a metabolic response counteracting the cold effects, resulting in better fruit stress acclimation. This treatment also preserved the peppers' color and antioxidant capacity. In summary, these findings highlight the suitability of applying a combined Wax + M500 treatment as a highly effective strategy to enhance the CI tolerance of peppers and extend their postharvest life.

First report of Colletotrichum queenslandicum associated with chilli anthracnose in Mauritius.

Globally, chilli (Capsicum annuum L.) is one of the most economically important and widely cultivated crop which elicits ethnomedicinal and nutritional potential as well as enhancing the taste and aroma of foods (Ayob et al., 2022; Kiran et al., 2020). Anthracnose disease is regarded as a prime constraint in chilli production, leading to enormous losses in tropical and subtropical countries. In September 2022, chilli fruit displaying sunken, shriveled and dark bown to black lesion with abundant acervuli on the surface was obtained from Flacq, Mauritius. From the symptomatic tissue, small pieces of the diseased tissue were excised, surface-disinfected using 1% sodium hypochlorite, twice rinsed using sterilized distilled water, air-dried and plated on PDA. After 7 days of incubation at room temperature, white to greyish white colony with dense white cottony aerial mycelium was recovered. Out of two isolates, CHF and CH10, the latter was considered for morphological and molecular characterization. The observed conidia (n=30) were unicellular, straight, cylindrical with rounded ends and slight constriction near the centre and had average length and width of 20.5 µm and 6 µm, respectively. For growth rate measurement of the isolate, two 5×5 mm of fungal agar plugs were taken from growing edge of colony, inoculated at centre of individual PDA plate and incubated at room temperature with a natural light/dark cycle. The diameter of the cultures were measured perpendicularly for a period of 7 days and the growth rate was calculated as 7-day average of daily growth (mm day-1). The growth rate of the fungal isolate (CH10) was 13.5 mm day-1 on PDA. Based on the morphological characters, the isolate was classified within the C. gloeosporioides species complex. For precise identification of the isolate, DNA was extracted from fungal mycelium using traditional DNA isolation methods (Ranghoo and Hyde, 2000), followed by PCR amplification and DNA sequencing using primer pairs ITS4/ITS5 (White et al., 1990), GDF/GDR and T1/Bt2b (Gan et al., 2016), respectively. ITS gene sequence (600 bp) confirmed that the isolate was Colletotrichum, with 99.83% similarity to KR704204 while GADPH (277 bp), TUB2 (733 bp) and ApMat (801 bp) gene sequences showed 99.64 to 100% similarity to C. queenslandicum with GenBank reference sequences, KT372374, KU221378 and MG674932 respectively. The gene sequences of isolate CH10 were deposited in GenBank database under the following accession numbers OR681557 (ITS), OR233734 (GADPH), OR475575 (TUB2) and PP622748 (ApMat). Koch's postulates were confirmed by spraying disease-free chilli plants with 10µL of conidial suspension (1 × 106 spores/ml) prepared from 7 days old colony of isolate CH10. Healthy chilli plants inoculated with sterile distilled water served as a negative control experiment. The plants were grown in pots in a moist chamber at 25˚C. After 5 days post-inoculation, anthracnose symptoms were developed on test plants while the control plant remained asymptomatic. The original isolate was successfully recovered from the test fruits, thus fulfilling Koch's postulates. The experiment was repeated thrice and revealed the same results. To the best of our knowledge, this is the first record of C. queenslandicum in Mauritius and is the first time to report anthracnose of chilli caused by this fungus. Colletotrichum queenslandicum has previously been reported in Europe, Mexico, US, Puerto Rico, Australia, Fiji, Brazil, Indonesia and China. Furthermore, the latter was associated with papaya, avocado, cashew, coffee, Persian lime, Licania tomentosa, white mangrove, lychee, mango, Nephelium lappaceum, olive, passionfruit, Dracaena cambodiana and Syzygium australe (Câmara and Vieira, 2022; Shidiq et al., 2024; Wang et al., 2022). This study will allow local farmers training and extension facilities to increase awareness among farmers about this disease-causing agent and allow them to take necessary measures for building up chilli crops resilience against this new and emerging pathogen in Mauritius.

Unlocking the Potential of Pepper Plants under Salt Stress: Mycorrhizal Effects on Physiological Parameters Related to Plant Growth and Gas Exchange across Tolerant and Sensitive Genotypes.

Agriculture is confronted with the challenge of ensuring global food security, yet the rapid expansion of salinity stress undoubtedly restricts plant productivity in cultivable areas, posing a significant threat to crop yields. Arbuscular mycorrhizal fungi (AMFs) have emerged as a biological tool for enhancing plant salt stress tolerance. To utilize this biological tool, this study evaluated the response in growth and physiological parameters of tolerant (Karaisali) and sensitive (Demre) pepper genotypes. The experiment involved mycorrhizal-treated (Glomus clarium) and non-mycorrhizal (control) plants of both the tolerant and sensitive pepper genotypes. The plants were subjected to two salt doses: 75 and 150 mM. The plant growth and physiological parameters were measured at 40 days after transplanting. The mycorrhizal activity was found to be significantly more effective in the sensitive genotype. We found notable differences in mycorrhizal activity between the pepper genotypes under salt stress conditions, with the sensitive genotype "Demre" showing greater responsiveness to mycorrhizal association compared with the "Karaisali" variety. Under both moderate (75 mM NaCl) and higher salt stress levels (150 mM NaCl), both the "Karaisali" and "Demre" varieties exhibited substantial increases in their shoot dry weights. However, these increases were consistently higher in the "Demre" plants. Moreover, the AMFs demonstrated significant enhancements in photosynthesis rates under both moderate and high salinity levels in both genotypes. Overall, our findings suggest that AMFs play a crucial role in improving plant growth, water status, and photosynthesis characteristics, particularly in salt-sensitive pepper genotypes, under moderate-to-high salinity levels. In conclusion, the plant growth, water status, and photosynthesis characteristics of the salt-sensitive pepper genotype were significantly improved by AMFs at medium and high salinity levels, such as 75 mM and 150 mM NaCl, respectively.

Unveiling the Biomedical Applications of Novel Coumarins Isolated From Capsicum Annuum L. Seeds by a Multivariate Extraction Technique.

For the first time, kinetic thermomagnetic extraction is a novel approach presented in this work. It required the application of four distinct variables: rotation speed (50, 75, and 100 rpm), magnetic field (0.8, 1.2, and 1.6 T), time interval (30, 60, and 90 min), and temperature (45, 55, and 65 °C). Numerous phytochemical categories were detected in the 81 crude chloroform extracts of green sweet bell pepper seeds that were collected, according to phytochemical analysis. Nine extracts were discovered to be linked to the coumarin chemical class and to have the same two extraction parameters: a 90-minute extraction duration and a 55 °C extraction temperature. To enable their coumarin contents to be chemically separated and chromatographically purified, two of these extracts containing coumarin were chosen. Four new phytocoumarins have been identified and their molecular structures distinguished using FTIR spectra, 1H-NMR, 13C-NMR, and mass analysis. By using MTT probing, it was discovered that these phytocoumarins exhibited anticancer activities against eight malignant populations and reduced oxidative stress in human SH-SY5Y populations. Similarly, the anti-inflammatory and antidiabetic properties were determined using three and two associated enzymes, respectively. The results demonstrated that the extracted phytocoumarins have exceptional oxidative stress-mitigating characteristics, ranging from 71.51 to 81.48 %, when compared to a positive control. Furthermore, they showed excellent cytotoxicity against the test malignant populations (IC50 values of 46.76-81.45 µg/ml). The isolates need to be taken into account as dual COX-2/5-LOX antagonists because they also showed a fascinating selective anti-inflammatory effect. The phytocoumarins under investigation have selectivity indices that are higher than those of the standards used, suggesting that they may have the ability to selectively block the COX2 enzyme that induces harmful inflammation. Compared to the standards, the phytocoumarins have a higher ability to block the catalytic activity of 5-LOX. This observation suggests that the phytocoumarins are powerful 5-LOX agents. Finally, they had a modest antidiabetic impact when tested against two blood-controlling enzymes. The authors came to the conclusion that the technique adopted is flexible and successful for extraction after modifying its components. Moreover, isolated phytocoumarins in general and natural-B1 in particular provide naturally derived solutions for oxidative stress and its associated diseases.

Potential Suitable Habitats of Chili Pepper in China under Climate Change.

Chili pepper (Capsicum annuum L.) is extensively cultivated in China, with its production highly reliant on regional environmental conditions. Given ongoing climate change, it is imperative to assess its impact on chili pepper cultivation and identify suitable habitats for future cultivation. In this study, the MaxEnt model was optimized and utilized to predict suitable habitats for open-field chili pepper cultivation, and changes in these habitats were analyzed using ArcGIS v10.8. Our results showed that the parameter settings of the optimal model were FC = LQPTH and RM = 2.7, and the critical environmental variables influencing chili pepper distribution were annual mean temperature, isothermality, maximum temperature of the warmest month, and precipitation of the warmest quarter. Under current climate conditions, suitable habitats were distributed across all provinces in China, with moderately- and highly-suitable habitats concentrated in the east of the Qinghai-Tibetan Plateau and south of the Inner Mongolia Plateau. Under future climate scenarios, the area of suitable habitats was expected to be larger than the current ones, except for SSP126-2050s, and reached the maximum under SSP126-2090s. The overlapping suitable habitats were concentrated in the east of the Qinghai-Tibetan Plateau and south of the Inner Mongolia Plateau under various climate scenarios. In the 2050s, the centroids of suitable habitats were predicted to shift towards the southwest, except for SSP126, whereas this trend was reversed in the 2090s. Our results suggest that climate warming is conductive to the cultivation of chili pepper, and provide scientific guidance for the introduction and cultivation of chili pepper in the face of climate warming.

Synergistic Influence of Arbuscular mycorrhizal Fungi Inoculation with Nanoparticle Foliar Application Enhances Chili (Capsicum annuum L.) Antioxidant Enzymes, Anatomical Characteristics, and Productivity under Cold-Stress Conditions.

In this study, we aimed to evaluate the effects of Arbuscular mycorrhiza fungus (AMF) inoculation, foliar application of zinc oxide and selenium nanoparticles (ZnO-NPs and Se-NPs), and their combined interactions on the growth and productivity of chili pepper under cold-stress conditions. Two field experiments were successfully conducted during the winter seasons of 2021 and 2022 in an experimental field at the Faculty of Agriculture, Cairo University, Giza, Egypt. The results showed that, under cold stress, the combination of AMF inoculation and ZnO-NPs + Se-NPs as a foliar spray increased the average fruit weight by 92.4% and 98.7%, and the number of fruits by 34.6% and 54.8 compared to control treatment in the 2021 and 2022 seasons, respectively. Additionally, the combination of AMF and a mixture of nanoparticles (ZnO-NPs + Se-NPs) significantly increased the total marketable yield by 95.8% and 94.7% compared to the control, which recorded values of 2.4 and 1.9 kg m-2 in the 2021 and 2022 seasons, respectively. Furthermore, the combination of AMF and a mixture of nanoparticles (ZnO-NPs + Se-NPs) showed the highest total content of ascorbic acid and capsaicin in chili fruits compared to the other treatments. The combination of AMF and a mixture of nanoparticles (ZnO-NPs + Se-NPs) stimulated the accumulation of peroxidase (POD) and nitrogen glutamate dehydrogenase (GDH) while decreasing hydrogen peroxide (H2O2) and lipid peroxidation (MDA) contents. SDS analysis revealed that the application of ZnO-NPs, Se-NPs, AMF + ZnO-NPs, and AMF + ZnO-NPs + Se-NPs induced the emergence of new protein bands and reconstitution of those damaged by cold stress. Regarding histological structure, the combination of AMF inoculation and ZnO-NPs + Se-NPs as a foliar spray showed an enhancement in the thickness of grana thylakoids and increased the number of chloroplasts. Intriguingly, the findings showed that AMF and a mixture of nanoparticles (ZnO-NPs + Se-NPs) could offer guidance for increasing plant development and productivity under cold-stress conditions.

Genome-Wide Analysis of the TCP Transcription Factor Gene Family in Pepper (Capsicum annuum L.).

TCP transcription factors play a key role in regulating various developmental processes, particularly in shoot branching, flower development, and leaf development, and these factors are exclusively found in plants. However, comprehensive studies investigating TCP transcription factors in pepper (Capsicum annuum L.) are lacking. In this study, we identified 27 CaTCP members in the pepper genome, which were classified into Class I and Class II through phylogenetic analysis. The motif analysis revealed that CaTCPs in the same class exhibit similar numbers and distributions of motifs. We predicted that 37 previously reported miRNAs target 19 CaTCPs. The expression levels of CaTCPs varied in various tissues and growth stages. Specifically, CaTCP16, a member of Class II (CIN), exhibited significantly high expression in flowers. Class I CaTCPs exhibited high expression levels in leaves, while Class II CaTCPs showed high expression in lateral branches, especially in the CYC/TB1 subclass. The expression profile suggests that CaTCPs play specific roles in the developmental processes of pepper. We provide a theoretical basis that will assist in further functional validation of the CaTCPs.

Phytochemical Profile, Antioxidant and Cytotoxic Potential of Capsicum annuum (L.) Dry Hydro-Ethanolic Extract.

Capsicum annuum (L.) is one of the essential spices most frequently used in our daily routine and has remarkable ethnobotanical and pharmacological properties. Its fruits are rich in vitamins, minerals, carotenoids, and numerous other phenolic metabolites with a well-known antioxidant activity. Regular consumption of chili fruits may have a positive influence on human health. Therefore, we investigated a commercially available chili fruit powder in the present study, extracting it with 50% ethanol. The dried hydro-ethanolic extract (CAE) was thoroughly analyzed using ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-HRMS/MS), and 79 bioactive phenolic constituents were identified. Then, we quantified the main phenolic compounds and found a polyphenol content of 4.725 ± 1.361 mg Eq tannic acid/100 g extract and a flavonoid amount of 1.154 ± 0.044 mg Eq rutin/100 g extract. Phenolic secondary metabolites are known for their dual redox behavior as antioxidants/pro-oxidants, underlying their numerous benefits in health and disease. Thus, the antioxidant potential of CAE was evaluated using three methods; our results could explain the protective effects of chili fruits: IC50DPPH = 1.669 mg/mL, IC50ABTS = 0.200 mg/mL, and EC50FRAP = 0.561 mg/mL. The pro-oxidant potential of phenolic compounds could be a basis for CAE cytotoxicity, investigated in vitro on tumor cell lines and in vivo on Daphnia sp. Results demonstrated the dose- and time-dependent CAE's cytotoxic activity; the highest antiproliferative activity was recorded on colon (LoVo) and breast (MDA-MB-231) cancer cell lines after 48 h of exposure (IC50 values < 200 µg/mL). In vivo testing on Daphnia sp. reported a potent CAE cytotoxicity after 48 h and embryonic developmental delays. Extensive data analyses support our results, showing a significant correlation between the CAE's concentration, phenolic compound content, antioxidant activity, exposure time, and the viability rate of different tested cell lines.

Differential responses of chili varieties grown under cadmium stress.

Heavy metal cadmium (Cd) naturally occurs in soil and is a hazardous trace contaminant for humans, animals, and plants. The main sources of Cd pollution in soil include overuse of phosphatic fertilizers, manure, sewage sludge, and aerial deposition. That's why an experiment was conducted to analyze the effect of Cd toxicity in Capsicum annuum L. by selecting its seven varieties: Hybrid, Desi, Sathra, G-916, BR-763, BG-912, and F1-9226. Cadmium was spiked in soil with four levels, i.e., (0, 3, 4, and 5 mg Cd kg- 1 of soil) for a week for homogeneous dispersion of heavy metal. Chili seeds were sown in compost-filled loamy soil, and 25-day-old seedlings were transplanted into Cd-spiked soil. Cadmium increasing concentration in soil decreased chili growth characteristics, total soluble sugars, total proteins, and amino acids. On the other hand, the activities of antioxidant enzymes were increased with the increasing concentration of Cd in almost all the varieties. Treatment 5 mg Cd/kg application caused - 197.39%, -138.78%, -60.77%, -17.84%, -16.34%, -11.82% and - 10.37% decrease of carotenoids level in chili V2 (Desi) followed by V4 (G-916), V1 (Hy7brid), V7 (F1-9226), V6 (BG-912), V5 (BR-763) and V3 (Sathra) as compared to their controls. The maximum flavonoids among varieties were in V5 (BR-763), followed by V6 (BG-912), V7 (F1-9226), V3 (Sathra) and V1 (Hybrid). Flavonoids content was decreased with - 37.63% (Sathra), -34.78% (Hybrid), -33.85% (G-916), -31.96% (F1-9226), -31.44% (Desi), -30.58% (BR-763), -22.88% (BG-912) as compared to their control at 5 mg Cd/kg soil stress. The maximum decrease in POD, SOD, and CAT was - 31.81%, -25.98%, -16.39% in chili variety V7 (F1-9226) at 5 mg Cd/kg stress compared to its control. At the same time, maximum APX content decrease was - 82.91%, followed by -80.16%, -65.19%, -40.31%, -30.14%, -10.34% and - 6.45% in V4 (G-916), V2 (Desi), V3 (Sathra), V6 (BG-912), V1 (Hybrid), V7 (F1-9226) and V5 (BR-763) at 5 mg Cd/kg treatment as compared to control chili plants. The highest CAT was found in 5 chili varieties except Desi and G-916. Desi and G-916 varieties. V5 (BR-763) and V6 (BG-912) were susceptible, while V1 (Hybrid), V3 (Sathra), and V7 (F1-9226) were with intermediate growth attributes against Cd stress. Our results suggest that Desi and G-916 chili varieties are Cd tolerant and can be grown on a large scale to mitigate Cd stress naturally.

Genome-wide analysis of the TIFY family and function of CaTIFY7 and CaTIFY10b under cold stress in pepper (Capsicum annuum L.).

TIFY [TIF(F/Y)XG] proteins are a plant particular transcription factor family that regulates plant stress responses. Therefore, to fill this gap, we investigated CaTIFY genes in pepper. Gene structure and conserved motifs of the pepper TIFY gene family were systematically analyzed using sequence alignment analysis, Cis-acting element analysis, transcriptomic data, and RT-qPCR analysis, and their expression patterns were further analyzed using Virus-Induced Gene Silencing (VIGS) and cold stress reactive oxygen species (ROS) response. We identified 16 CaTIFY genes in pepper, which were dispersed among seven subgroups (JAZI, JAZII, JAZIII, PPD, TIFY, and ZIM/ZML). Several CaTIFY members had stress-related harmonic-responsive elements, and four (CaTIFY7, CaTIFY10b, CaTIFY1b, and CaTIFY6b) had low-temperature-responsive elements. Transcriptomic data and RT-qPCR analysis revealed that the TIFY genes in pepper displayed different expression patterns in the roots, stems, leaves, flower fruits, and seeds. In particular, CaTIFY7 was highly expressed in young leaves, and CaTIFY10b was highly expressed in roots. CaTIFYs participated in the regulation of several different abiotic stresses and CaTIFY7 and CaTIFY10b were significantly induced by cold stress. Additionally, Virus-Induced Gene Silencing (targeting CaTIFY7 and CaTIFY10b) resulted in plants that were sensitive to cold stress. Conversely, overexpression of CaTIFY7 and CaTIFY10b enhanced plant cold tolerance by promoting the expression of genes related to cold stress and the ROS response. CaTIFY7 and CaTIFY10b interacted with themselves and CaTIFY7 also interacted with CaTIFY10b in the yeast two-hybrid (Y2H) system. Our data provide a basis for further analysis of the role of pepper TIFY genes in cold-stress responses in the future.

Enhancing the nutritional value of sweet pepper through sustainable fertilization management.

Introduction: The need for healthy foods has become a major concern in our modern world, as the global population continues to grow and environmental challenges intensify. In response to these challenges, researchers have started to explore a range of sustainable solutions, including organic farming practices, precision agriculture, and the development and testing of innovative biofertilizers. Consistent with these ideas come the aim of this study, which sets out to give new insights into the cultivation of two sweet pepper cultivars with economic and nutritional importance in Romania. Methods: Two sweet pepper cultivars (Blancina and Brillant), chemically (Nutrifine®), organically (Orgevit®) and biologically (Micoseed®) fertilized were cultivated over the course of two years (2019 and 2020), between April and October, in high-tunnel, by following a split-plot design with three replications. Production parameters (number of fruits, fruit weight, yield), proximate composition (water content, dry matter, total soluble solids, acidity, ash), the content of phytonutrients (polyphenols, lycopene, ß-carotene, antioxidant activity), phytochemical composition (phenolic compounds) and minerals (macro- and micro-elements) were analyzed in order to determine the impact of fertilization on the quality of sweet peppers. Results: The results showed that the biological and organic fertilizations had a significant positive impact on most of the parameters analyzed, starting with yield and continuing with acidity, phytonutrient content (total phenolic content, lycopene, ß-carotene), antioxidant activity and phytochemical composition (chlorogenic acid, p-coumaric acid, quercetin and isoquercetin). Only in the case of mineral content, the chemical treatment gave better results compared with the organic and biological fertilizers. Conclusion: Overall, this study provides valuable information on the potential of organic and biological fertilizers to enhance the nutritional value of sweet peppers from Blancina F1 and Brillant F1 cultivars, paving the way for subsequent research aimed at achieving superior quality and increased yields.

Polysaccharides and Phenolic Compounds Recovered from Red Bell Pepper, Tomato and Basil By-Products Using a Green Extraction by Extractor Timatic®.

Fruits and vegetables processing produces significant amounts of by-products rich in valuable bioactive compounds such as polyphenols and dietary fiber. Food by-product re-use promotes the eco-sustainability of several crops. This study aimed to apply green extractions of bioactive compounds from by-products of basil, tomato, and red bell pepper production. Tests were performed by applying extraction procedures both at laboratory scale and using the Timatic® extractor. Water and ethanol 10% and 20% were used for extraction of red bell pepper and tomato, testing different temperatures (30, 50, and 90 °C; water at 90 °C and ethanol 20% were applied for basil. The obtained phenolic extracts were analyzed by HPLC-DAD-MS. Polysaccharides of tomato and red bell pepper were extracted at laboratory scale and chemically characterized using 1H-NMR to define the methylation and acylation degree, and DLS to estimate the hydrodynamic volume. Laboratory extraction tests allowed efficient scaling-up of the process on the Timatic® extractor. Phenolic content in the dried extracts (DE) ranged 8.0-11.2 mg/g for tomato and red bell pepper and reached 240 mg/g for basil extracts. Polysaccharide yields (w/w on DM) reached 6.0 and 10.4% for dried tomato and red bell pepper, respectively. Dry extracts obtained using the Timatic® extractor and water can be useful sources of bioactive phenols. The study provided new data on tomato and red bell pepper polysaccharides that may be useful for future applications.

Amplicon sequencing data profiling of rhizospheric microbiome associated with Capsicum annuum L. var. Kulai cultivated under organic farming.

Data on the 16S rRNA and 18S rRNA amplicon sequencing from the rhizosphere of Capsicum annuum L. var. Kulai cultivated under organic farming are unveiled. The most dominant phyla for the 16S rRNA gene were Actinobacteriota and Proteobacteria. As for the 18S rRNA gene amplicon, Charophyta and Fungi were the major taxonomic groups.

Molecular Regulatory Mechanism of Exogenous Hydrogen Sulfide in Alleviating Low-Temperature Stress in Pepper Seedlings.

Pepper (Capsicum annuum L.) is sensitive to low temperatures, with low-temperature stress affecting its plant growth, yield, and quality. In this study, we analyzed the effects of exogenous hydrogen sulfide (H2S) on pepper seedlings subjected to low-temperature stress. Exogenous H2S increased the content of endogenous H2S and its synthetase activity, enhanced the antioxidant capacity of membrane lipids, and protected the integrity of the membrane system. Exogenous H2S also promoted the Calvin cycle to protect the integrity of photosynthetic organs; enhanced the photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), and photosynthesis; and reduced the intercellular CO2 concentration (Ci). Moreover, the activities of superoxide dismutase, peroxidase, catalase, and anti-cyclic glutathione (ASA-GSH) oxidase were improved to decompose excess reactive oxygen species (ROS), enhance the oxidative stress and detoxification ability of pepper seedlings, and improve the resistance to low-temperature chilling injury in 'Long Yun2' pepper seedlings. In addition, the H2S scavenger hypotaurine (HT) aggravated the ROS imbalance by reducing the endogenous H2S content, partially eliminating the beneficial effects of H2S on the oxidative stress and antioxidant defense system, indicating that H2S can effectively alleviate the damage of low temperature on pepper seedlings. The results of transcriptome analysis showed that H2S could induce the MAPK-signaling pathway and plant hormone signal transduction; upregulate the expression of transcription factors WRKY22 and PTI6; induce defense genes; and activate the ethylene and gibberellin synthesis receptors ERF1, GDI2, and DELLA, enhancing the resistance to low-temperature chilling injury of pepper seedlings. The plant-pathogen interaction was also significantly enriched, suggesting that exogenous H2S also promotes the expression of genes related to plant-pathogen interaction. The results of this study provide novel insights into the molecular mechanisms and genetic modifications of H2S that mitigate the hypothermic response.

Novel transcriptome networks are associated with adaptation of capsicum fruit development to a light-blocking glasshouse film.

Light-blocking films (LBFs) can contribute to significant energy savings for protected cropping via altering light transmitting, such as UVA, photosynthetically active radiation, blue and red spectra affecting photosynthesis, and capsicum yield. Here, we investigated the effects of LBF on orange color capsicum (O06614, Capsicum annuum L.) fruit transcriptome at 35 (mature green) and 65 (mature ripe) days after pollination (DAP) relative to untreated control in a high-technology glasshouse. The results of targeted metabolites showed that LBF significantly promotes the percentage of lutein but decreased the percentage of zeaxanthin and neoxanthin only at 35 DAP. At 35 DAP, fruits were less impacted by LBF treatment (versus control) with a total of 1,192 differentially expressed genes (DEGs) compared with that at 65 DAP with 2,654 DEGs. Response to stress and response to light stimulus in biological process of Gene Ontology were found in 65-DAP fruits under LBF vs. control, and clustering analysis revealed a predominant role of light receptors and phytohormone signaling transduction as well as starch and sucrose metabolism in LBF adaptation. The light-signaling DEGs, UV light receptor UVR8, transcription factors phytochrome-interacting factor 4 (PIF4), and an E3 ubiquitin ligase (COP1) were significantly downregulated at 65 DAP. Moreover, key DEGs in starch and sucrose metabolism (SUS, SUC, and INV), carotenoid synthesis (PSY2 and BCH1), ascorbic acid biosynthesis (VTC2, AAO, and GME), abscisic acid (ABA) signaling (NCED3, ABA2, AO4, and PYL2/4), and phenylpropanoid biosynthesis (PAL and DFR) are important for the adaptation of 65-DAP fruits to LBF. Our results provide new candidate genes for improving quality traits of low-light adaptation of capsicum in protected cropping.

Effect of Hydrogen Peroxide Application on Salt Stress Mitigation in Bell Pepper (Capsicum annuum L.).

The present study aimed to evaluate the effects of the foliar application of hydrogen peroxide on the attenuation of salt stress on the growth, photochemical efficiency, production and water use efficiency of 'All Big' bell pepper plants. The experiment was conducted under greenhouse conditions in Campina Grande, PB, Brazil. Treatments were distributed in a randomized block design, in a 5 × 5 factorial scheme, corresponding to five levels of electrical conductivity of irrigation water (0.8, 1.2, 2.0, 2.6 and 3.2 dS m-1) and five concentrations of hydrogen peroxide (0, 15, 30, 45 and 60 µM), with three replicates. Foliar application of hydrogen peroxide at concentration of 15 µM attenuated the deleterious effects of salt stress on photochemical efficiency, biomass accumulation and production components of bell pepper plants irrigated using water with an electrical conductivity of up to 3.2 dS m-1. Foliar spraying of hydrogen peroxide at a concentration of 60 µM intensified the effects of salt stress. The 'All Big' bell pepper was classified as moderately sensitive to salt stress, with an irrigation water salinity threshold of 1.43 dS m-1 and a unit decrease of 8.25% above this salinity level.

Multi-environment association study highlights candidate genes for robust agronomic quantitative trait loci in a novel worldwide Capsicum core collection.

Investigating crop diversity through genome-wide association studies (GWAS) on core collections helps in deciphering the genetic determinants of complex quantitative traits. Using the G2P-SOL project world collection of 10 038 wild and cultivated Capsicum accessions from 10 major genebanks, we assembled a core collection of 423 accessions representing the known genetic diversity. Since complex traits are often highly dependent upon environmental variables and genotype-by-environment (G × E) interactions, multi-environment GWAS with a 10 195-marker genotypic matrix were conducted on a highly diverse subset of 350 Capsicum annuum accessions, extensively phenotyped in up to six independent trials from five climatically differing countries. Environment-specific and multi-environment quantitative trait loci (QTLs) were detected for 23 diverse agronomic traits. We identified 97 candidate genes potentially implicated in 53 of the most robust and high-confidence QTLs for fruit flavor, color, size, and shape traits, and for plant productivity, vigor, and earliness traits. Investigating the genetic architecture of agronomic traits in this way will assist the development of genetic markers and pave the way for marker-assisted selection. The G2P-SOL pepper core collection will be available upon request as a unique and universal resource for further exploitation in future gene discovery and marker-assisted breeding efforts by the pepper community.

Fine mapping of the flavonoid 3',5'-hydroxylase gene controlling anthocyanin biosynthesis in pepper anthers and stems.

Pepper (Capsicum annuum L) is one of the most important vegetables grown worldwide. Nevertheless, the key structural and regulatory genes involved in anthocyanin accumulation in pepper have not been well understood or fine mapped yet. In this study, F1, F2, BC1P1, and BC1P2 pepper populations were analyzed and these populations were derived from a cross between line 14-Z4, which has yellow anthers and green stems, and line 14-Z5, which has purple anthers and stems. The results showed that the yellow anthers and green stems were determined by a single recessive locus called to as ayw. While, using preliminary and fine mapping techniques, ayw locus was located between markers aywSNP120 and aywSNP124, with physical distance of 0.2 Mb. The CA11g18550 gene was identified as promising candidate for the ayw locus, as it co-segregated with the yellow anthers and green stems phenotypes. CA11g18550 encodes a homolog of the F3'5'H (flavonoid 3',5'-hydroxylase) anthocyanin synthesis structure gene. The missense mutation of CA11g18550 possibly resulted in a loss-of-function. The expression analysis showed that CA11g18550 was significantly expressed in the stems, leaves, anthers and petals in 14-Z5, and it's silencing caused the stems changing from purple to green. This study provides a theoretical basis for using yellow anthers and green stems in pepper breeding and helps to advance the understanding of anthocyanin synthesis.

Investigating the characteristics of fluorescence features on sweet peppers using UV light excitation.

Sweet peppers are popular worldwide due to their nutrition and taste. Conventional vegetable tracing methods have been trialed, but the application of such labels or tags can be laborious and expensive, making their commercial application impractical. What is needed is a label-free method that can identify features unique to each individual fruit. Our research team has noted that sweet peppers have unique textural fluorescence features when observed under UV light that could potentially be used as a label-free signature for identification of individual fruit as it travels through the postharvest supply chain. The objective of this research was to assess the feature of these sweet pepper features for identification purposes. The macroscopic and microscopic images were taken to characterize the fluorescence. The results indicate that all sweet peppers possess dot-like fluorescence features on their surface. Furthermore, it was observed that 93.60% of these features exhibited changes in fluorescence intensity within the cuticle layer during the growth of a pepper. These features on the macro-image are visible under 365 nm UV light, but challenging to be seen under white LEDs and to be classified from the fluorescence spectrum under 365 nm light. This research reported the fluorescence feature on the sweet pepper, which is invisible under white light. The results show that the uniqueness of fluorescent features on the surface of sweet peppers has the potential to become a traceability technology due to the presence of its unique physical modality.