Fruit Pericarp Research Articles

Coupled bio-solar photocatalytic treatment for reclamation of water polluted with pharmaceutical and pesticide residues. Impact on tomato irrigation

Reusing reclaimed water for crop irrigation can mitigate water scarcity in agriculture; however, contaminants such as pharmaceuticals and pesticides in wastewater pose risks. This study investigated the impact of a coupled bio-solar photocatalytic treatment on the reclamation of water polluted with seven pharmaceuticals and seven pesticides for irrigation of two tomato crop cycles. Pollutant residues were removed using natural sunlight and TiO2/Na2S2O8 in a pilot plant located in Murcia, Spain. Efficient removal (> 96%) of all target pollutants was achieved in the effluent after coupled treatment. Reclaimed water was then used to irrigate the tomato crops, and several yield and quality parameters were analysed to evaluate the effects on the harvested tomatoes. No significant differences were observed in the total yield, number and mean fruit weight, size, pericarp firmness, external colour, and nutritional data between the crops irrigated with reclaimed, control, and polluted water. However, differences in the degree of ripeness were observed. None of the investigated pollutants was detected above the limit of quantification in tomato samples irrigated with reclaimed water, except for venlafaxine (0.028µgkg-1) in the second crop cycle. When the crop was irrigated with polluted water, different pollutant residues were detected in soil (10) and tomato (4) samples. The results suggest that coupled bio-solar photocatalytic treatment is an effective method for reclaiming water polluted with pharmaceutical and pesticide residues, and the reclaimed water can be safely used for tomato irrigation without compromising crop yield and quality.

Effects of Postharvest SO2 Treatment on Longan Aril Flavor and Glucosinolate Metabolites.

SO2 fumigation treatment (commonly known as sulfur treatment, ST) is a key method in the postharvest preservation of imported and exported fresh longan fruits, effectively reducing pericarp browning and enhancing color. Nonetheless, distinctive aromas, often referred to as "sulfur flavor", may develop in the aril during the extended preservation period. This study employed "Caopu" longan as the test material and patented SO2-releasing paper (ZL201610227848.7) as a treatment to perform a 35-day low-temperature (5 °C) storage of the fruit. The changes in glucosinolates (GSLs) and associated metabolites in the aril of treated fruit (ST) were examined utilizing ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) detection and widely targeted metabolomics technology. The findings indicated that following 35 days of storage, nearly all control (CK) fruit pericarp turned to brown, resulting in an edible fruit rate of 75.41% and a commercial fruit rate of 0%. In contrast, the treated (ST) fruit demonstrated an edible fruit rate and a commercial rate of 99.44%, while the pericarp color changed from dark yellow-brown to light earthy yellow. The sulfur-containing metabolites identified in longan fruit aril predominantly consist of amino acids and their derivatives (60.44%), followed by alkaloids (15.38%), nucleotides and their derivatives (1.10%), and other types (23.08%), which include GSLs. SO2 treatment significantly reduced the content of oxidized glutathione in fruit aril but increased the content of GSLs and related amino acids and their derivatives. Via screening, 19 differential sulfur-containing metabolites were obtained between ST and CK, including 11 GSLs. The identified differential metabolites of GSLs were all increased, primarily comprising aliphatic GSLs, such as 1-hydroxymethyl glucosinolate, 2-Propenyl glucosinolate (Sinigrin), and 4-Methylsulfinylbutyl glucosinolate (Glucoraphanin). Pathway analysis showed that these differential metabolites were mainly involved in coenzyme factor synthesis, cysteine and methionine metabolism, and amino acid synthesis, among other pathways. To the best of our knowledge, this is the first study to reveal the causes of the special flavor of longan aril after SO2 treatment, which is a great concern for longan consumers. Moreover, this study provides a scientific basis for exploring the reasons and mechanisms for the development of the sulfur flavor in the SO2-treated fruits during postharvest storage.

α-Mangostin: A Xanthone Derivative in Mangosteen with Potent Anti-Cancer Properties

α-Mangostin, a xanthone derivative extracted from the pericarp of the mangosteen fruit (Garcinia mangostana L.), has garnered significant attention for its potential as a natural anti-cancer agent. This review provides a comprehensive analysis of the current literature on the anti-cancer properties of α-mangostin across various cancer types. Through an extensive analysis of in vitro and in vivo studies, this review elucidates the multifaceted mechanisms underlying α-mangostin’s cytotoxicity, apoptosis induction through both intrinsic and extrinsic pathways, and modulation of key cellular processes implicated in cancer progression in a diverse array of cancer cells. It causes mitochondrial dysfunction, activates caspases, and regulates autophagy, endoplasmic reticulum stress, and oxidative stress, enhancing its anti-cancer efficacy. Moreover, α-mangostin exhibits synergistic effects with conventional chemotherapeutic agents, suggesting its utility in combination therapies. The ability of α-mangostin to inhibit cell proliferation, modulate cell cycle progression, and induce apoptosis is linked to its effects on key signaling pathways, including Akt, NF-κB, and p53. Preclinical studies highlight the therapeutic potential and safety profile of α-mangostin, demonstrating significant tumor growth inhibition without adverse effects on normal cells. In summary, understanding the molecular targets and mechanisms of action of α-mangostin is crucial for its development as a novel chemotherapeutic agent, and future clinical investigations are warranted to explore its clinical utility and efficacy in cancer prevention and therapy.

Anti-neoplastic Effects of Juglans Regia L. Green Fruit Pericarp on Breast Cancer Cell Lines

Background: Recently, more attention has been paid to the use of complementary medicine in breast cancer (BC) treatment. Juglans green fruit pericarp was found to have anti-cancer characteristics. Objectives: We aimed here to assess the possible anti-proliferative effects of methanolic extract of Juglans green fruit pericarp in BC cell lines. Methods: MCF-7 and MDA-MB-231 cells were examined with different concentrations of Juglans green fruit pericarp extract. The cell viability was investigated using a 3 - 2, 5-diphenyl tetrazolium bromide (MTT) assay. Also, different phases of the cell cycle were analyzed utilizing a flow cytometry method. Finally, the ability of cancer cells to create colonies was studied post-treatment with Juglans green fruit pericarp. Results: Our findings showed that the methanol extract has substantial cytotoxicity on MCF-7 and MDA-MB-231 cell lines. We also observed a significant arrest in the G0/G1 phase in cancer cells post-treatment with the methanol extract. Conclusions: In summary, our results introduced a cytotoxic property for Juglans green fruit pericarp methanol extract for MCF-7 and MDA-MB-231 cell lines. Future studies are needed to further evaluate its utility as a potential complementary therapy for BC.

Effects of salt stress on the fruit and yield quality of some selected tomato (<i>Lycopersicum esculentum</i> L.) varieties.

The growth, production, and nutritional characteristics of crops are impacted by abiotic factors such as salinity stress. The study aimed to assess the impact of salt stress on the fruit and yield characteristics of three distinct tomato cultivars, namely Rio, Dan syria, and UTC. Salt solutions with varying concentrations of NaCl were created by dissolving NaCl in deionized water. Four treatments were established, consisting of solutions with salt concentrations of 0g/L (control, without salt), 0.5g/L, 1.0g/L, and 1.5g/L. Each treatment was reproduced three times. The NaCl solutions were administered with a frequency of 7 days. The data in the study underwent Analysis of Variance (ANOVA). Rio outperformed the other varieties in terms of fruit quantity, fresh fruit weight, and fruit pericarp thickness under high salt stress, closely followed by UTC variety. The study also found that Dan syria performed better than the other varieties in terms of fresh and dry weight of shoot, as well as fresh weight of root, under mild and extreme salinity stress. However, Rio performed better than the other varieties in terms of dry weight of root under both mild and extreme salinity stress. The salt tolerance index of the Rio, UTC, and Dan Syria varieties under extreme salinity stress are 46.79%, 20.64%, and 34.70% respectively. This indicated that the Rio variety is the most salt-tolerant of the three types, with Dan Syria variety coming close.

Updating the Pharmacological Effects of α-Mangostin Compound and Unraveling Its Mechanism of Action: A Computational Study Review.

α-Mangostin, initially identified in 1855, is a xanthone derivative compound predominantly located in the pericarp of the mangosteen fruit (Garcinia mangostana L). This compound is known for its beneficial properties as an antioxidant and anti-inflammatory agent, still holding promise for potential benefits in other related pathologies. In the investigative process, computational studies have proven highly valuable in providing evidence and initial screening before progressing to preclinical and clinical studies. This review aims to present the pharmacological findings and mechanisms of action of α-mangostin based on computational studies. The compilation of this review is founded on the analysis of relevant articles obtained from PubMed, Scopus, and ScienceDirect databases. The study commences with an elucidation of the physicochemical characteristics, drug-likeness, pharmacokinetics, and toxicity profile of α-mangostin, which demonstrates that α-mangostin complies with the Lipinski's Rule of Five, exhibits favorable profiles of absorption, distribution, metabolism, and excretion, and presents low toxicity. Subsequent investigations have revealed that computational studies employing various software tools including ArgusLab, AutoDock, AutoDock Vina, Glide, HEX, and MOE, have been pivotal to comprehend the pharmacology of α-mangostin. Beyond its well established roles as an antioxidant and anti-inflammatory agent, α-mangostin is now recognized for its pharmacological effects in Alzheimer's disease, diabetes, cancer, chronic kidney disease, chronic periodontitis, infectious diseases, and rheumatoid arthritis. Moreover, α-mangostin is projected to have applications in pain management and as a potent mosquito larvicide. All of these findings are based on the attainment of adequate binding affinity to specific target receptors associated with each respective pathological condition. Consequently, it is anticipated that these findings will serve as a foundation for future scientific endeavours, encompassing both in vitro and in vivo studies, as well as clinical investigations, to better understand the pharmacological effects of α-mangostin.

Synthesis of pH-sensitive polymeric micelle drug carries for potential cancer chemotherapy applications

Alpha mangostin, a natural xanthone derivative from mangosteen fruit pericarp, exhibits antiproliferative and apoptotic effects on different cancer cells by inhibiting cell cycle progression, inducing apoptosis, and modulating signaling pathways. However, this candidate is limited in medical treatment due to the poor water solubility. Nanoparticles have emerged as promising drug delivery systems to improve drug delivery efficiency but one of the problem of nanoparticles is the capability of endosomal escape. Therefore, pH-sensitive polymer nanosystems were utilized for targeted drug delivery, and enhanced efficacy by offering controlled release and endosomal escape capabilities. This study aimed to synthesize PEG- P(Asp-Hyd-Man) copolymer and create micelle for alpha mangostin delivery. The micelles were measured with particle size average of 80.2 ± 15 nm, and the PDI of 0.17. Additionally, the release behavior of alpha mangostin was examined in vitro that show pH-sensitive polymeric micelles rapidly release at pH 5.0 compared with the arterial pH 7.4. The findings of this study are significant in the development of an effective drug delivery system using alpha mangostin and other therapeutic agents.

Fruit anatomy and histogenesis in Mediterranean species of Arbutus (Ericaceae: Arbutoideae): ecological and morphogenetic aspects

Abstract Details of fruit anatomy and pericarp histogenesis were studied in Mediterranean species of Arbutus with the aim to determine the morphogenetic fruit type, to reveal the functional and ecological significance of fruit structure, and to suggest the most probable scenarios of fruit structural transformations in Arbutoideae (Ericaceae). The pericarp of the coenocarpous berries of Arbutus is differentiated into: one-layered exocarp, multilayered parenchymatous mesocarp with scattered solitary and groups of sclereids, and one-layered endocarp composed of thin-walled cells. The warts covering the fruit surface are formed by parenchymatous cells of the mesocarp and the exocarp. The process of pericarp development in Arbutus is divided into four periods, which correlate with the phenology and climatic factors of the Mediterranean region. The origin of the dormancy period in the middle part of fruit development in Arbutus is interpreted as an important adaptation to the arid Mediterranean climate. The data obtained suggest that both the berry of Arbutus and the pyrenariums of Arctostaphylos and Arctous are highly specialized fruit types that could not have derived from each other. The capsule of Hamamelis type of Enkianthoideae is recognized as the original fruit type of the berries and pyrenariums of Arbutoideae.

Domestication and Genetic Improvement Alter the Symbiotic Microbiome Structure and Function of Tomato Leaf and Fruit Pericarp.

Many studies have attempted to explore the changes in the structure and function of symbiotic microbiomes, as well as the underlying genetic mechanism during crop domestication. However, most of these studies have focused on crop root microbiomes, while those on leaf and fruit are rare. In this study, we generated a comprehensive dataset including the metagenomic (leaf) and metatranscriptomic (fruit pericarp in the orange stage) data of hundreds of germplasms from three tomato clades: Solanum pimpinellifolium (PIM), cherry tomato (S. lycopersicum var. cerasiforme) (CER), and S. lycopersicum group (BIG). We investigated the effect of domestication and improvement processes on the structure of the symbiotic microbiome of tomato leaf and fruit pericarp, as well as its genetic basis. We were able to obtain the composition of the symbiotic microbiome of tomato leaf and fruit pericarp, based on which the tomato clade (PIM, CER, or BIG) was predicted with high accuracy through machine learning methods. In the processes of tomato domestication and improvement, changes were observed in the relative abundance of specific bacterial taxa, Bacillus for example, in the tomato leaf and fruit pericarp symbiotic microbiomes, as well as in the function of these symbiotic microbiomes. In addition, SNP loci that were significantly associated with microbial species that are characteristic of tomato leaf were identified. Our results show that domestication and genetic improvement processes alter the symbiotic microbiome structure and function of tomato leaf and fruit pericarp. We propose that leaf and fruit microbiomes are more suitable for revealing changes in symbiotic microbiomes during the domestication process and the underlying genetic basis for these changes due to the exclusion of the influence of environmental factors such as soil types on the microbiome structure.

Structural elucidation a complex galactosyl andglucosyl-rich pectin from the pericarp of immature fruits of Juglans mandshurica Maxim.

A glucosyl-rich pectin, JMMP-3 (Mw, 2.572 × 104g/mol, O-methyl % = 3.62%), was isolated and purified from the pericarp of the immature fruit of Juglans mandshurica Maxim. (QingLongYi). The structure of JMMP-3 was studied systematically by infrared spectroscopy, monosaccharide compositions, methylation analysis, partial acid hydrolysis, and 1/2D-NMR. The backbone of JMMP-3 possessed a smooth region (→ 4GalA1 →) and a hairy region (→ 4GalA1 → 2Rha1 →) with a molar ratio of 2: 5. The substitution of four characteristic side chains (R1-R4) occurs at C-4 of → 2,4)-α-Rhap-(1→, where R1 is composed of → 5)-α-Araf-(1→, R2 is composed of → 4)-β-Galp-(1 → and β-Galp-(1→, R3 is composed of α-Glcp-(1→, →4)-α-Glcp-(1 → and → 4,6)-α-Glcp-(1→, and R4 is composed of → 5)-α-Araf-(1→, β-Galp-(1→, → 4)-β-Galp-(1→, → 3,4)-β-Galp-(1→, → 4,6)-β-Galp-(1 → and → 2,4)-β-Galp-(1 → . In addition, the antitumor activity of JMMP-3 on HepG2 cells was preliminarily investigated.

INFLUENCE OF DROUGHT STRESS ON THE FRUIT AND YIELD QUALITY OF THREE DIFFERENT VARIETIES OF TOMATO (Lycopersicum esculentum L.)

Drought impacts various physiological processes in plants, ultimately affecting yield. The study aimed to determine the influence of drought stress on the fruit and yield quality of three different varieties of tomato namely; Rio, Dan Syria and UTC. The plants were subjected to four treatments which were subjected to 80-85% WHC (water holding capacity) (control, T1), 55-60% WHC (light drought stress, T2), 40-45% WHC (moderate drought stress, T3) and 30-35% WHC (severe drought stress, T4) and each replicated three times. The data generated were subjected to Analysis of Variance (ANOVA). According to the findings, Rio outperformed the other varieties in terms of fresh fruit weight (21.59g), fruit pericarp thickness (3.96mm) and drought tolerance index (56.17%) under severe drought conditions. However, under severe drought conditions, the highest average number of fruits (2.33) was produced by the UTC, closely followed by Dan Syria (2). The results also showed that under severe drought stress, Rio outperformed the other varieties in terms of fresh and dry weight of shoot, as well as fresh and dry weight of root (18.82g, 3.47g and 3.34g, 1.29g) closely followed by Dan Syria measuring 12.47g, 1.66g, 3.10g, and 0.62g respectively. Under conditions of severe drought stress, Rio, UTC, and Dan Syria exhibit drought tolerance indices of 56.17%, 37.49%, and 20.44% respectively. These suggest that Rio is the most resilient to drought compared to the other varieties. Therefore, farmers should consider using Rio, which has a high level of drought resistance, as a means to mitigate the impact of drought.

Xanthone Inhibitors of Unfolded Protein Response Isolated from Calophyllum caledonicum.

The unfolded protein response (UPR) is a key component of fungal virulence. The prenylated xanthone γ-mangostin isolated from Garcinia mangostana (Clusiaceae) fruit pericarp, has recently been described to inhibit this fungal adaptative pathway. Considering that Calophyllum caledonicum (Calophyllaceae) is known for its high prenylated xanthone content, its stem bark extract was fractionated using a bioassay-guided procedure based on the cell-based anti-UPR assay. Four previously undescribed xanthone derivatives were isolated, caledonixanthones N-Q (3, 4, 8, and 12), among which compounds 3 and 8 showed promising anti-UPR activities with IC50 values of 11.7 ± 0.9 and 7.9 ± 0.3 μM, respectively.

Morphological and agronomical characterization of beef type tomato hybrids

Tomato (Solanum lycopersicum L.) is one of the most important vegetable crops and agro-morphological characterization has a key role in the development of new varieties. In this study, 228 samples of the tomato hybrid type “Beef” (Solanum lycopersicum L.) were characterized by comparing with 11 standard varieties based on 24 quantitative traits and 2 qualitative traits to reveal the phenotypic diversity by using conventional descriptors proposed by IPGRI (1996) and UPOV (2011). A significant level of variability was found in most of the traits studied among the genotypes in two locations. A high level of broad-sense heritability (H2) was detected for many traits such as the number of fruits, firmness, immature fruit color, stem length up to the first inflorescence, total height, and number of days to the first flowering in both locations. There was a highly significant positive correlation among the color values (L*, a*, b*, c*, h*) but no positive correlation between a* and h*. Number of locule had a positive correlation with fruit width and fruit weight, and a positive correlation was determined between fruit length and pericarp thickness in both locations. While fruit weight had a highly significant negative correlation with the number of fruits and number of flowers, there was a highly significant negative correlation between the number of locules and the fruit length-to-width ratio in both locations. Results of PCA showed that PC1 and PC2 accounted for around 15.6% and 13.7% of total variation and 13.8% and 11.8% of total variation for Location 1 and Location 2, respectively. The first five principal components accounted for around 54.2% of the total variation for Location 1 and 48.2% of the total variation for Location 2. Cluster analysis grouped the 239 genotypes under six cluster groups for Location 1 and seven cluster groups for Location 2. Results of the cluster analysis revealed that Cluster 3 for Location 1 and Cluster 2 for Location 2 had prominent genotypes for some of the agronomically important traits like yield. The results showed that present phenotypic diversity could be useful in the selection of best-performing genotypes, which would be important candidates for the beef red tomato market in the spring season.

Effects of Foliar Ca and Mg Nutrients on the Respiration of ‘Feizixiao’ Litchi Pulp and Identification of Differential Expression Genes Associated with Respiration

The ‘Feizixiao’ litchi cultivar, predominantly grown in Hainan Province, faces the issue of “sugar receding” during fruit ripening. The application of mixed foliar nutrients containing calcium and magnesium (Ca+Mg) during the fruit pericarp’s full coloring stage was investigated to overcome this issue. Experimental trials unveiled significant alterations in litchi pulp physiochemical properties, including the main nutrient and flavor quality, the total respiration rates of the main respiratory pathways, and the activities of some important enzymes associated with Embden–Meyerhof–Parnas (EMP), the tricarboxylic acid cycle (TCA) and the pentose phosphate pathway (PPP). The Ca+Mg treatment showed higher sugar levels than the control (CK) during ripening. Notably, the application of Ca+Mg in litchi pulp inhibited respiration rates through the EMP, TCA, and PPP pathways, resulting in a strong effect. RNA sequencing analysis revealed the impact of Ca+Mg treatment on respiratory pathways, revealing differentially expressed genes (DEGs) such as pyruvate PK1, PK2 (pyruvate kinase), and PDC (pyruvate dehydrogenase complex), validated through qRT-PCR with a significant correlation to RNA-seq results. In general, Ca+Mg treatment during litchi fruit ripening overcame “sugar receding” by inhibiting the expression of respiration key metabolic pathway genes. These findings provide insights for enhancing cultivation management strategies.

Vitexin is a potential postharvest treatment for ameliorating litchi fruit pericarp browning by regulating autophagy

Pericarp browning is a vital factor limiting postharvest life of litchi fruit. The influence of vitexin on pericarp browning as well as the related mechanisms in litchi fruit were investigated. Results demonstrated that 1 mM vitexin ameliorated pericarp browning when litchi fruit were stored at 25 °C. Meanwhile, vitexin blocked reactive oxygen species (ROS) production but increased the glutathione peroxidase activity, thereby playing a protective role in oxidative injury. Additionally, vitexin attenuated ATP content decline in relation to regulation of LcSnRK1 as well as LcbZIP1/3 expressions. Furthermore, vitexin regulated expression levels of autophagy-related genes. Finally, LcbZIP3 activated the expressions of LcATG2 and Lcbeclin-1-like protein based on dual-luciferase report (DLR) assay. This is the first report that confers vitexin-meditated protective role in delaying litchi pericarp browning that could be linked to its effects on autophagy particularly regulated via LcSnRK1a–LcbZIP1/3 signaling pathway. Vitexin treatment might be an effective approach to control postharvest senescence of fruit during storage.

Exogenous melatonin delays oxidative browning in litchi during cold storage by regulating biochemical attributes and gene expression.

Oxidative damage leading to loss of nutritional quality and pericarp discoloration of harvested litchi fruits drastically limits consumer acceptance and marketability. In the present investigation, the impact of postharvest melatonin application at different concentrations, i.e., 0.1 mM, 0.25 mM, and 0.5 mM, on fruit quality and shelf life of litchi fruits under cold storage conditions was studied. The results revealed the positive effect of melatonin application at all concentrations on fruit quality and shelf life. However, treatment with 0.5 mM concentration of melatonin resulted in minimum weight loss, decay loss, pericarp discoloration, and also retained higher levels of TSS, acidity, total sugar, ascorbic acid, anthocyanin, antioxidant, and phenolics content during cold storage. Melatonin administration also restricted the enzymatic activity of the polyphenol oxidase (PPO) and peroxidase (POD) enzymes in the fruit pericarp and maintained freshness of the fruits up to 30 days in cold storage. At the molecular level, a similar reduction in the expression of browning-associated genes, LcPPO, LcPOD, and Laccase, was detected in preserved litchi fruits treated with melatonin. Anthocyanin biosynthetic genes, LcUFGT and LcDFR, on the other hand showed enhanced expression in melatonin treated fruits compared to untreated fruits. Melatonin, owing to its antioxidant properties, when applied to harvested litchi fruits retained taste, nutritional quality and red color pericarp up till 30 days in cold storage.

Adsorptive Sequestration of Methylene Blue Dye from Aqueous Solution Using Novel Roystonea regia fruit Pericarp: Isotherm, Kinetics, and Thermodynamics

The batch adsorptive sequestration of methylene blue from an aqueous solution using unripe Roystonea regia fruit pericarp biomass was investigated in this study. The characteristic nature of the biosorbent was studied using various analytical instruments including Fourier Transform Infra-red spectrophotometer, Scanning Electron Microscope, Energy Dispersive X-ray, X-ray diffractometer, and the Brunauer-Emmett Teller. The adsorption study was perfomed at different experimental conditions including pH, contact time, initial dye concentration, temperature, agitation speed, and biosobent dose. From the results of this study, the optimum biosorption of MB was achieved at 120 min contact time, pH 10, room temperature (298 K), 150 rpm agitation speed and dosage of 100 mg/150 mL dye solution. With 132.30 mgg-1 maximum sorption capacity, the Langmuir isotherm best describes the biosorption equilibrium data. At all initial concentrations, the biosorption kinetics of methylene blue onto the biosorbent fitted best to the pseudo-second order kinetics model, with R2 values ≥ 0.999 and qcal being similar to the qexp. The kinetics study also showed the involvement of intra-particle diffusion in the rate-determining step; although not as the sole limiting step of the sorption process. The results of the thermodynamics study showed the high feasibility, spontaneity, and exothermic nature of the biosorption of methylene blue onto the biosorbent. This study concludes that Roystnea regia fruit pericarp would make an economically viable and renewable biosorbent for practical eco-friendly sequestration of MB dye from wastewaters.

Oxylipin biosynthesis via an unprecedented 16-hydroperoxide lyase pathway in green tissues of cucumber (Cucumis sativus L.) plants

The plant lipoxygenase cascade is a source of various regulatory oxylipins that play a role in cell signalling, stress adaptation, and immune response. Recently, we detected an unprecedented 16(S)-lipoxygenase, CsLOX3, in the leaves and fruit pericarp of cucumber (Cucumis sativus L.). In the present work, an array of products biosynthesized through the conversions of α-linolenic acid 16-hydroperoxide (16-HPOT) was detected. Firstly, a prominent 15-hydroxy-9,12-pentadecadienoic acid (Me/TMS) was detected, the product of hydroperoxide lyase (HPL) chain cleavage of 16-HPOT and further reduction of aldehyde 15-oxo-9,12-pentadecadienoic acid to alcohol. Besides, the presence of dicarboxylic acid, 3,6-pentadecadiene-1,15-dioic acid, was deduced from the detection of its catalytic hydrogenation product, pentadecane-1,15-dioic acid. Finally, 12,15-dihydroxypentadecanoic acid (Me/TMS) was detected amongst the hydrogenated products, thus indicating the presence of the parent 12,15-dihydroxy-9,13-pentadecadienoic acid. To confirm the proposed HPL chain cleavage, the 16(S)-HPOT was prepared and incubated with the recombinant cucumber HPL CYP74B6 enzyme. The CYP74B6 possessed high activity towards 16-HPOT. Chain cleavage yields the (9Z,12Z)-15-oxo-9,12-pentadecadienoic acid, undergoing a spontaneous isomerization into (9Z,13E)-15-oxo-9,13-pentadecadienoic acid. Thus, the cucumber plants as well as the recombinant cucumber HPL CYP74B6 possessed unprecedented 16-HPL activity, cleaving 16-HPOT into a C15 fragment, 15-oxo-9,12-pentadecadienoic acid, and a complementary volatile C3 fragment, propionic aldehyde. The 16-LOX/16-HPL route of oxylipin biosynthesis presents a novel facet of the plant LOX pathway.

REDUCED CHLOROPLAST COVERAGE proteins are required for plastid proliferation and carotenoid accumulation in tomato.

Increasing the amount of cellular space allocated to plastids will lead to increases in the quality and yield of crop plants. However, mechanisms that allocate cellular space to plastids remain poorly understood. To test whether the tomato (Solanum lycopersicum L.) REDUCED CHLOROPLAST COVERAGE (SlREC) gene products serve as central components of the mechanism that allocates cellular space to plastids and contribute to the quality of tomato fruit, we knocked out the 4-member SlREC gene family. We found that slrec mutants accumulated lower levels of chlorophyll in leaves and fruits, accumulated lower levels of carotenoids in flowers and fruits, allocated less cellular space to plastids in leaf mesophyll and fruit pericarp cells, and developed abnormal plastids in flowers and fruits. Fruits produced by slrec mutants initiated ripening later than wild type and produced abnormal levels of ethylene and abscisic acid (ABA). Metabolome and transcriptome analyses of slrec mutant fruits indicated that the SlREC gene products markedly influence plastid-related gene expression, primary and specialized metabolism, and the response to biotic stress. Our findings and previous work with distinct species indicate that REC proteins help allocate cellular space to plastids in diverse species and cell types and, thus, play a central role in allocating cellular space to plastids. Moreover, the SlREC proteins are required for the high-level accumulation of chlorophyll and carotenoids in diverse organs, including fruits, promote the development of plastids and influence fruit ripening by acting both upstream and downstream of ABA biosynthesis in a complex network.

The YABBY Transcription Factor, SlYABBY2a, Positively Regulates Fruit Septum Development and Ripening in Tomatoes.

The tomato fruit is a complex organ and is composed of various structures from the inside out, such as columella, septum, and placenta. However, our understanding of the development and function of these internal structures remains limited. In this study, we identified a plant-specific YABBY protein, SlYABBY2a, in the tomato (Solanum lycopersicum). SlYABBY2a exhibits relatively high expression levels among the nine YABBY genes in tomatoes and shows specific expression in the septum of the fruit. Through the use of a gene-editing technique performed by CRISPR/Cas9, we noticed defects in septum development in the Slyabby2a mutant fruits, leading to the inward concavity of the fruit pericarp and delayed septum ripening. Notably, the expression levels of key genes involved in auxin (SlFZY4, SlFZY5, and SlFZY6) and ethylene (SlACS2) biosynthesis were significantly downregulated in the septum of the Slalkbh10b mutants. Furthermore, the promoter activity of SlYABBY2a was regulated by the ripening regulator, SlTAGL1, in vivo. In summary, these discoveries provide insights into the positive regulation of SlYABBY2a on septum development and ripening and furnish evidence of the coordinated regulation of the auxin and ethylene signaling pathways in the ripening process, which expands our comprehension of septum development in the internal structure of the fruit.