Determination of α-methylenecyclopropylglycine in Shahi and China litchi cultivars at three different maturity stages: A quantitative study using liquid chromatography tandem mass spectrometry.

This study presents the contents of α-methylenecyclopropylglycine, a potentially toxic amino acid, in the peel, pulp and seed fractions of two well-known litchi varieties, namely Shahi and China, over a span of three harvest-seasons. For analysing α-methylenecyclopropylglycine, an LC-MS/MS-based method was validated. The method-accuracies fell within 75-110 % (RSD, <15 %) at 0.1 mg/kg (LOQ) and higher levels. A comparative evaluation of the results in peel, pulp and seed at 30 days before harvest (DBH), 15-DBH, and edible-ripe stage revealed that α-methylenecyclopropylglycine content increased as the litchi seeds grew towards maturity, regardless of the cultivar. In arils, at maturity, the concentration of α-methylenecyclopropylglycine ranged from not-detected to 11.7 µg/g dry weight. The Shahi cultivar showed slightly higher α-methylenecyclopropylglycine content in comparison to China litchi. This paper presents the first known analysis of combined seasonal data on different fruit components at various growth stages for the two chosen litchi cultivars grown in India.

Targeted Metabolites and Transcriptome Analysis Uncover the Putative Role of Auxin in Floral Sex Determination in Litchi chinensis Sonn.

Litchi exhibits a large number of flowers, many flowering batches, and an inconsistent ratio of male and female flowers, frequently leading to a low fruit-setting rate. Floral sexual differentiation is a crucial phase in perennial trees to ensure optimal fruit production. However, the mechanism behind floral differentiation remains unclear. The objective of the study was to identify the role of auxin in floral differentiation at the transcriptional level. The results showed that the ratio of female flowers treated with naphthalene acetic acid (NAA) was significantly lower than that of the control stage (M0/F0). The levels of endogenous auxin and auxin metabolites were measured in male and female flowers at different stages of development. It was found that the levels of IAA, IAA-Glu, IAA-Asp, and IAA-Ala were significantly higher in male flowers compared to female flowers. Next-generation sequencing and modeling were employed to perform an in-depth transcriptome analysis on all flower buds in litchi 'Feizixiao' cultivars (Litchi chinensis Sonn.). Plant hormones were found to exert a significant impact on the litchi flowering process and flower proliferation. Specifically, a majority of differentially expressed genes (DEGs) related to the auxin pathway were noticeably increased during male flower bud differentiation. The current findings will enhance our comprehension of the process and control mechanism of litchi floral sexual differentiation. It also offers a theoretical foundation for implementing strategies to regulate flowering and enhance fruit production in litchi cultivation.

Integrative approaches to improve litchi (Litchi chinensis Sonn.) plant health using bio-transformations and entomopathogenic fungi.

Bio-transformations refer to the chemical modifications made by an organism on a chemical compound that often involves the interaction of plants with microbes to alter the chemical composition of soil or plant. Integrating bio-transformations and entomopathogenic fungi into litchi cultivation can enhance symbiotic relationships, microbial enzymatic activity in rhizosphere, disease suppression and promote overall plant health. The integration of biological formulations and entomopathogenic fungi can significantly influence growth, nutrient dynamics, physiology, and rhizosphere microbiome of air-layered litchi (Litchi chinensis Sonn.) saplings. Biological modifications included, K-mobilizers, AM fungi, Pseudomonas florescence and Azotobacter chroococcum along with Metarhizium, entomopathogenic fungi have been used. The treatments included, T1-Litchi orchard soil + sand (1:1); T2-Sand + AM fungi + Azotobacter chroococcum (1:2:1); T3-Sand + Pseudomonas florecence + K-mobilizer (1:1:1); T4- AM fungi + K-mobilizers (1:1); T5, P. Florecence + A. chroococcum + K-mobilizer (1:1:1); T6-Sand + P. florecence (1:2) and T7-Uninoculated control for field performance. Treatments T4-T6 were further uniformly amended with drenching of Metarrhizium in rhizosphere. T2 application significantly increased resident microbe survival, total chlorophyll content and root soil ratio in seedlings. A. chroococcum, Pseudomonas, K-mobilizers and AM fungi increased in microbial biomass of 2.59, 3.39, 2.42 and 2.77 times, respectively. Acidic phosphatases, dehydrogenases and alkaline phosphatases were increased in rhizosphere. Leaf nutrients reflected through DOP were considerably altered by T2 treatment. Based on Eigen value, PCA-induced changes at biological modifications showed maximum total variance. The study inferred that the bio-transformations through microbial inoculants and entomopathogenic fungi could be an encouraging strategy to enhance the growth of plants, health and productivity. Such practices align well with the goals of sustainable agriculture through biological means by reducing dependency on chemical inputs. By delving into these aspects, the research gaps including microbial processes, competitive and symbiotic relationships, resistance in microbes and how complex interactions among bio-transformations, entomopathogenic fungi and microbes can significantly impact the health and productivity of litchi. Understanding and harnessing these interactions can lead to more effective and sustainable farming practices.

Litchi Procyanidins Ameliorate DSS-Induced Colitis through Gut Microbiota-Dependent Regulation of Treg/Th17 Balance.

Ulcerative colitis (UC) is a common chronic, relapsing inflammatory bowel condition. Procyanidins (PC) are known for their antiangiogenic, anti-inflammatory, antioxidant, and antimetastatic properties. However, there is comparatively limited information on how PC interacts with UC. In this study, 5 mg/10 mL/kg body weight of PC was administered to mice with dextran sulfate sodium (DSS)-induced colitis mice. PC treatment prolonged the survival period of mice, ameliorated UC symptoms, reduced damage to the intestinal mucosal barrier, and increased the protein expression of ZO-1 and occludin in the DSS-treated mice. Importantly, PC treatment significantly reduced gene expression related to Th17 cell differentiation, including STAT3, SMAD3, TGF-ß, and JAK1. The results of the flow cytometry analysis indicated significant increase in the number of Treg cells and a concomitant decrease in the proportion of Th17 cells in the colon following PC treatment. Additionally, PC increased the abundance of gut microbiota such as Bacteroidota, Oscillospiraceae, Muribaculaceae, and Desulfovibrionaceae, as well as the concentrations of acetate acid, propionate acid, and butyrate acid in the feces. PC also activated short-chain fatty acid receptors, such as G-protein coupled receptor 43 in the colon, which promoted the proliferation of Treg cells. The depletion of gut microbiota and subsequent transplantation of fecal microbiota demonstrated that PC's effects on gut microbiota were effective in improving UC and restoring intestinal Th17/Treg homeostasis in a microbiota-dependent manner. This suggests that PC could be a promising functional food for the prevention and treatment of UC in the future.

Hydrogen sulfide alleviates pericarp browning in lichi fruit by modulating energy and sugar metabolisms.

Postharvest litchi is susceptible to browning that limits the development of litchi industry. Hydrogen sulfide (H2S) is an important bioactive molecule that can regulate many physiological processes. This study examined the effects of exogenous H2S on pericarp browning and related physiological mechanisms in postharvest litchi. The results exhibited that exogenous H2S treatment delayed the browning of litchi pericarp and reduced the damage to cell membrane integrity during storage. This treatment inhibited the energy losses of litchi fruit by increasing the activities of H+-ATPase, Ca2+- ATPase, cytochrome C oxidase (CCO) and succinate dehydrogenase (SDH) and regulating the expression of energy metabolism-related genes, including LcAtpB, LcSnRK2, LcAAC1, LcAOX1 and LcUCP1. In addition, H2S treatment increased the levels of fructose, glucose, sucrose, inositol, galactose and sorbose in litchi fruit, and promoted sucrose synthesis by regulating the activities of sucrose phosphate synthase (SPS), sucrose synthase (SS), acid invertase (AI) and neutral invertase (NI). Based on the current findings, we suggest that exogenous H2S enhances the energy supply and antioxidant activity of litchi by modulating energy and sugar metabolism, thereby inhibiting fruit browning and senescence. These results indicated that H2S treatment is an effective approach to maintaining the quality of litchi fruit and extending its shelf life.

Active bio-nanocomposites from litchi seed starch, tamarind kernel xyloglucan, and lignin nanoparticles to improve the shelf-life of banana (Musa acuminata).

Valorization of agricultural byproducts to biodegradable packaging films aids in reducing plastic dependency and addressing plastic perils. Herein, starch (LSS) from litchi seeds and xyloglucan (XG) from tamarind kernels were recovered, and composite films were developed. The XG addition strengthened the weak polymer networks of LSS and improved rheological, molecular, morphological, mechanical, and water vapor barrier properties. The incorporation of lignin nanoparticles (LNPs) into the LSS-XG network further increased the tensile strength (14.83 MPa), elastic modulus (0.41 GPa), and reduced surface wettability (80.07°), and water vapor permeability (5.63 ± 0.38 × 10-7 g m-1s-1Pa-1). The phenolic hydroxyls of LNPs imparted strong UV-shielding and free radical scavenging abilities to films. These attributes aided in preserving the quality of coated banana fruits with minimal weight loss and color change. Overall, this research highlights the potential transformation of underutilized abundant byproducts into sustainable active bio-nanocomposites for food packaging and shelf-life extension of fruits.

LcINH1 as an inhibitor of cell wall invertase LcCWIN5 regulates early seed development in Litchi chinensis Sonn.

Sugar signal mediated by Cell wall invertase (CWIN) plays a central role in seed development. In higher plants, invertase inhibitors (INHs) suppress CWIN activities at a post-translational level. In Litchi chinensis cultivar 'Nuomici', impaired CWIN expression is associated with seed abortion. Here, the expression of LcINH1 was significantly higher in the funicle of seed-aborting cultivar 'Nuomici' than big-seeded cultivar 'Heiye'. Promoter analyses found LcINH1 contained a 404 bp repeat fragment with an endosperm regulatory element of Skn-1_motif. LcINH1 and LcCWIN2/5 were located in plasma membrane. LcINH1 was able to interact with LcCWIN5, but not with LcCWIN2. In vitro enzyme activity assay demonstrated that LcINH1 could inhibit CWIN activity. Silencing LcINH1 in 'Nuomici' resulted in normal seed development, paralleled increased CWIN activities and glucose levels. Transcriptome analysis identified 1079 differentially expressed genes (DEGs) in LcINH1-silenced fruits. KEGG analysis showed significant enrichment of DEGs in pathways related to transporters and plant hormone signal transduction. Weighted gene co-expression network analysis indicated that the turquoise module was highly correlated with fructose content, and LcSWEET3b was closely associated with early seed development. These findings suggest that LcINH1 regulate LcCWIN5 activity at the post-translational level to alter sucrose metabolism, thereby affecting early seed development in litchi.

High hydrostatic pressure reduces inflammation induced by litchi thaumatin-like protein via altering active domain.

Thaumatin-like proteins (TLP), existing in various fruits, have allergenic and pro-inflammatory activities. The current research attempts to reduce the pro-inflammatory activity of litchi TLP (LcTLP) through high hydrostatic pressure (HHP). This study demonstrated that HHP (250-500 MPa, 5-10 min) was a potential technique to reduce the pro-inflammatory activity of LcTLP, which was attributed to the irreversible destruction of the active domain, ie., V-cleft. SDS-PAGE showed no change in the protein profile. Continuous HHP treatment promoted LcTLP unfolding and then reassembling (400 MPa was the transition pressure), and the content of ß-sheets decreased from 35.4% to 31.1%. HHP treatment could mitigate inflammatory responses of LcTLP, as confirmed by ELISA and western blot. Molecular dynamics simulations showed significant changes in the residue network under HHP, thereby affecting the V-cleft. These findings provide a theoretical explanation and structural insights into the HHP-induced reduction of pro-inflammatory activity of LcTLP.

Total flavonoids of litchi Seed alleviates schistosomiasis liver fibrosis in mice by suppressing hepatic stellate cells activation and modulating the gut microbiomes.

Infection with Schistosoma japonicum (S. japonicum) is an important zoonotic parasitic disease that causes liver fibrosis in both human and domestic animals. The activation of hepatic stellate cells (HSCs) is a crucial phase in the development of liver fibrosis, and inhibiting their activation can alleviate this progression. Total flavonoids of litchi seed (TFL) is a naturally extracted drug, and modern pharmacological studies have shown its anti-fibrotic and liver-protective effects. However, the role of TFL in schistosomiasis liver fibrosis is still unclear. This study investigated the therapeutic effects of TFL on liver fibrosis in S. japonicum infected mice and explored its potential mechanisms. Animal study results showed that TFL significantly reduced the levels of Interleukin-1ß (IL-1ß), Tumor Necrosis Factor-α (TNF-α), Interleukin-4 (IL-4), and Interleukin-6 (IL-6) in the serum of S. japonicum infected mice. TFL reduced the spleen index of mice and markedly improved the pathological changes in liver tissues induced by S. japonicum infection, decreasing the expression of alpha-smooth muscle actin (α-SMA), Collagen I and Collagen III protein in liver tissues. In vitro studies indicated that TFL also inhibited the activation of HCSs induced by Transforming Growth Factor-ß1 (TGF-ß1) and reduced the levels of α-SMA. Gut microbes metagenomics study revealed that the composition, abundance, and functions of the mice gut microbiomes changed significantly after S. japonicum infection, and TLF treatment reversed these changes. Therefore, our study indicated that TFL alleviated granulomatous lesions and improved S. japonicum induced liver fibrosis in mice by inhibiting the activation of HSCs and by improving the gut microbiomes.

LcMPK3 and LcMPK6 positively regulate fruitlet abscission in litchi.

Mitogen-activated protein kinase (MAPK) cascades have been discovered to play a fundamental role in regulating organ abscission. However, the identity of protein substrates targeted by MAPK cascades, as well as whether the role of MAPK protein cascades in the abscission process is conserved across different plant species, remain unknown. Here, the role of homologs of MPK3 and MPK6 in regulating fruit abscission were characterized in litchi. Ectopic expression of LcMPK3 or LcMPK6 in Arabidopsis mpk3 mpk6 mutant rescued the deficiency in floral organ abscission, while silencing of LcMPK3 or LcMPK6 in litchi significantly decreased fruitlet abscission. Importantly, a total of 49 proteins interacting with LcMPK3 were identified through yeast two-hybrid screening, including two components of the MAPK signaling cascade, five transcription factors, and two aquaporins. Furthermore, the interaction between LcMPK3/6 with LcBZR1/2, core components in brassinosteroids signaling that suppress litchi fruitlet abscission, was confirmed using in vitro and in vivo assays. Moreover, phos-tag assays demonstrated that LcMPK3/6 could phosphorylate LcBZR1/2, with several phosphorylation residues identified. Together, our findings suggest that LcMPK3 and LcMPK6 play a positive regulatory role in fruitlet abscission in litchi, and offer crucial information for the investigation of mechanisms underlying MPK3/6-mediated organ abscission in plants.

Antibacterial activity of a polysaccharide isolated from litchi (Litchi chinensis Sonn.) pericarp against Staphylococcus aureus and the mechanism investigation.

The long-term use of antibiotics can cause drug resistance. Natural polysaccharides are a novel means of treating bacterial infections, and the development and utilization of litchi pericarp polysaccharide (LPPs) as a bacteriostatic active substance offer a new research direction for the high-value utilization of litchi by-products. This study revealed that LPPs inhibited Staphylococcus aureus more than Escherichia coli, Listeria monocytogenes, and Salmonella typhimurium, with the minimum inhibitory concentrations of 145, 205, 325, and 445 µg/mL, respectively. The inhibitory activity of LPPs was insignificant for Bacillus subtilis at 505 µg/mL. The assessment of antibacterial mechanisms revealed that LPPs influenced the growth, conductivity, protein, and nucleic acid, reducing sugar, respiratory chain dehydrogenase activity, bacterial lipid peroxidation, intracellular adenosine triphosphate, and extracellular alkaline phosphatase levels of S. aureus. Of note, LPPs could modify the cell wall integrity and cell membrane permeability of S. aureus, resulting in the leakage of intracellular large and small molecules, inhibition of cellular respiratory metabolism, and oxidative losses. These processes exhibited an inhibitory effect and made the bacterium nonfunctional, thereby affecting its growth and metabolism or causing cell death. These findings provide support and insights into the potential application of LPPs as a natural antimicrobial agent.

Mechanisms of Litchi Response to Postharvest Energy Deficiency via Energy and Sugar Metabolisms.

In the post-harvest phase, fruit is inexorably subjected to extrinsic stressors that expedite energy expenditure and truncate the storage lifespan. The present study endeavors to elucidate the response strategies of litchi to the alterations of energy state caused by 2,4-Dinitrophenol (DNP) treatment through energy metabolism and sugar metabolism. It was observed that the DNP treatment reduced the energy state of the fruit, exacerbated membrane damage and triggered rapid browning in the pericarp after 24 h of storage. Furthermore, the expression of genes germane to energy metabolism (LcAtpB, LcAOX1, LcUCP1, LcAAC1, and, LcSnRK2) reached their peak within the initial 24 h of storage, accompanied by an elevation in the respiratory rate, which effectively suppressed the rise in browning index of litchi pericarp. The study also posits that, to cope with the decrease of energy levels and membrane damage, litchi may augment the concentrations of fructose, glucose, inositol, galactose, and sorbose, thus safeguarding the canonical metabolic functions of the fruit. Collectively, these findings suggest that litchi can modulate energy and sugar metabolism to cope with fruit senescence under conditions of energy deficiency. This study significantly advances the understanding of the physiological responses exhibited by litchi fruit to post-harvest external stressors.

Substantially altered bacterial diversity associated with developmental stages of litchi stink bug, Tessaratoma javanica (Thunberg) (Hemiptera: Tessaratomidae).

The mutualistic symbiotic relationship between insects and bacteria greatly influences the growth and development of host insects. Tessaratoma javanica (Thunberg) (Hemiptera: Tessaratomidae), also referred to as the litchi stink bug, has recently been established as an important insect pest of Litchi chinensis Sonn. and causes substantial yield loss in India. To design effective and environmentally safe management strategies, an understanding of the diversity and functions of microbiota harbored across the development stages is very important. The assessment of the diversity of development-associated bacteria in T. javanica and their predicted functions was conducted using 16S rRNA gene sequences obtained by the Illumina MiSeq technology. The result showed that taxonomic analysis of associated bacteria in different developmental stages includes a total of 46 phyla, encompassing 139 classes, 271 orders, 474 families, and 893 genera of bacteria. All developmental stages of T. javanica shared a total of 42.82 percent of operational taxonomic units (OTUs), with a 97 % similarity threshold. Alpha diversity indices showed maximum species richness in the egg and adult stages. The phyla Proteobacteria followed by Firmicutes, Bacteriodetes, and Actinobacteria, exhibited the highest levels of abundance across all the developmental stages of T. javanica. Microbiota were most different between the egg and the 4th nymphal stage (χ2 = 711.67) and least different between the 2nd and 4th nymphal instars (χ2 = 44.45). The predicted functions of the microbiota associated with T. javanica are mainly involved in amino acid metabolism, cell motility, cellular processes and signaling, glycan biosynthesis and metabolism, lipid metabolism, and membrane transport. The present study documentation and information on symbiotic bacteria across T. javanica life stages will prompt the development of novel biological management strategies.

Methanolic extracts of litchi (Litchi chinensis Sonn.): A novel approach of targeting glucose-6-phosphate dehydrogenase for liver cancer therapy.

Cancer metabolism has emerged as a potential target for innovative therapeutic approaches in the treatment of cancer. Cancer metabolism has received much attention, particularly in relation to glucose metabolism. It has been observed that human malignancies have high levels of glucose-6-phosphate dehydrogenase (G6PD) activity which is an important enzyme of glucose metabolism. This overactivity is associated with the cell death and angiogenesis, highlighting its potential as a viable target for cancer treatment. This study was conducted to examine the methanolic extracts from the seeds, bark and leaves of litchi (Litchi chinensis Sonn.) in order to discover effective compounds targeting G6PD and potentially active entities against liver cancer. Plant extract screening for the target protein was carried out through enzymatic activity assay. The recombinant plasmid pET-24a-HmG6PD was expressed in E. coli (BL21-DE3) strain, then purified and assessed using metal affinity chromatography with Ni-NTA columns and SDS-PAGE. The cytotoxicity of plant extracts against liver cancer HepG2 cells was assessed using the MTT assay. All three extracts demonstrated significant inhibitory effects (>80% inhibition) against G6PD. They were then subjected to testing at various concentrations, and their IC50 values were subsequently determined. The extracts of litchi (leaf, IC50: 1.199 µg/mL; bark, IC50: 2.350 µg/mL; seeds, IC50: 1.238 µg/mL) displayed significant inhibition of G6PD activity at lower concentrations. Subsequently, the leaf extract of litchi was further assessed for its impact on HepG2 cell lines in a dose-dependent manner and exhibited strong potential as an inhibitor of cancer cell progression. Moreover, the results of acute toxicity study in mice revealed nontoxic effects of litchi leaf extract on hepatocytes. The results imply that Litchi chinensis leaf extract could be considered as a promising candidate for safer drug development in the treatment of liver cancer.

Diversification of FT-like genes in the PEBP family contributes to the variation of flowering traits in Sapindaceae species.

Many species of Sapindaceae, such as lychee, longan, and rambutan, provide nutritious and delicious fruit. Understanding the molecular genetic mechanisms that underlie the regulation of flowering is essential for securing flower and fruit productivity. Most endogenous and exogenous flowering cues are integrated into the florigen encoded by FLOWERING LOCUS T. However, the regulatory mechanisms of flowering remain poorly understood in Sapindaceae. Here, we identified 60 phosphatidylethanolamine-binding protein-coding genes from six Sapindaceae plants. Gene duplication events led to the emergence of two or more paralogs of the FT gene that have evolved antagonistic functions in Sapindaceae. Among them, the FT1-like genes are functionally conserved and promote flowering, while the FT2-like genes likely serve as repressors that delay flowering. Importantly, we show here that the natural variation at nucleotide position - 1437 of the lychee FT1 promoter determined the binding affinity of the SVP protein (LcSVP9), which was a negative regulator of flowering, resulting in the differential expression of LcFT1, which in turn affected flowering time in lychee. This finding provides a potential molecular marker for breeding lychee. Taken together, our results reveal some crucial aspects of FT gene family genetics that underlie the regulation of flowering in Sapindaceae.

Spectrum-effect relationship between HPLC fingerprint and hypoglycemic of litchi leaves (Litchi chinensis Sonn) in vitro.

Litchi chinensis Sonn (Litchi) has been listed in the Chinese Pharmacopeia, and is an economically and medicinally valuable species within the family Sapindaceae. However, the material basis of its pharmacological action and the pharmacodynamic substances associated with its hypoglycemic effect are still unclear. The predominant objective of this study was to establish the fingerprint profile of litchi leaves and to evaluate the relationship between the components of the high-performance liquid chromatography (HPLC) fingerprint of litchi leaves, assess its hypoglycemic effect by measuring α-glucosidase and α-amylase inhibition, and find the spectrum-effect relationship of litchi leaves by bivariate correlation analysis, Grey relational analysis and partial least squares regression analysis. In this study, the fingerprint of litchi leaves was established by HPLC, and a total of 15 common peaks were identified that clearly calibrated eight components, with P1 being gallic acid, P2 being protocatechuic acid, P3 being catechin, P6 being epicatechin, P12 being rutin, P13 being astragalin, P14 being quercetin and P15 being kaempferol. The similarities between the fingerprints of 11 batches of litchi leaves were 0.766-0.979. Simultaneously, the results of the spectrum-effect relationship showed that the chemical constituents represented by peaks P8, P3, P12, P14, P2, P13, and P11 were relevant to the hypoglycemic effect.

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.

A crosslinked and percolation network alginate coating for litchi prevention.

The short shelf life of Litchi is due to its rapid metabolism after being harvested. Refrigeration is not a suitable method for preserving litchi, as the browning process of litchi that has been cryogenic will accelerate when it is brought to room temperature. This study introduces an alginate-based coating as a solution to control the post-harvest metabolism of litchi. The coating achieves this by simultaneously establishing crosslink and percolation networks, both of which act as barriers. The percolation network is created using rod-like cellulose nanocrystals, which possess excellent percolation properties. This network effectively reduces moisture loss. Compared to the control group, the coated litchi exhibited a 38.1 % lower browning index and a 62.5 % lower decay rate. Additionally, the soluble solid content increased by 107.1 %. The inclusion of cellulose nanocrystals and the crosslinking of calcium ions enhanced the mechanical properties of the composite membrane. Specifically, the tensile strength and elongation at break increased by 70 % and 366 % respectively. As all the components in the coating are edible, it is environmentally friendly and safe for human consumption.

Genome-Wide Identification and Expression Analysis of the Class III Peroxidase Gene Family under Abiotic Stresses in Litchi (Litchi chinensis Sonn.).

Class III peroxidases (CIII PRXs) are plant-specific enzymes with high activity that play key roles in the catalysis of oxidation-reduction reactions. In plants, CIII PRXs can reduce hydrogen peroxide to catalyze oxidation-reduction reactions, thereby affecting plant growth, development, and stress responses. To date, no systematic analysis of the CIII PRX gene family in litchi (Litchi chinensis Sonn.) has been documented, although the genome has been reported. In this study, a total of 77 CIII PRX (designated LcPRX) gene family members were predicted in the litchi genome to provide a reference for candidate genes in the responses to abiotic stresses during litchi growth and development. All of these LcPRX genes had different numbers of highly conserved PRX domains and were unevenly distributed across fifteen chromosomes. They were further clustered into eight clades using a phylogenetic tree, and almost every clade had its own unique gene structure and motif distribution. Collinearity analysis confirmed that there were eleven pairs of duplicate genes among the LcPRX members, and segmental duplication (SD) was the main driving force behind the LcPRX gene expansion. Tissue-specific expression profiles indicated that the expression levels of all the LcPRX family members in different tissues of the litchi tree were significantly divergent. After different abiotic stress treatments, quantitative real-time PCR (qRT-PCR) analysis revealed that the LcPRX genes responded to various stresses and displayed differential expression patterns. Physicochemical properties, transmembrane domains, subcellular localization, secondary structures, and cis-acting elements were also analyzed. These findings provide insights into the characteristics of the LcPRX gene family and give valuable information for further elucidating its molecular function and then enhancing abiotic stress tolerance in litchi through molecular breeding.

Litchi (Litchi chinensis Sonn.): A comprehensive and critical review on cancer prevention and intervention.

Litchi (Litchi chinensis Sonn.) is a tropical fruit with various health benefits. The objective of this study is to present a thorough analysis of the cancer preventive and anticancer therapeutic properties of litchi constituents and phytocompounds. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis criteria were followed in this work. Various litchi extracts and constituents were studied for their anticancer effects. In vitro studies showed that litchi-derived components reduced cell proliferation, induced cytotoxicity, and promoted autophagy via increased cell cycle arrest and apoptosis. Based on in vivo studies, litchi flavonoids and other extracted constituents significantly reduced tumor size, number, volume, and metastasis. Major signaling pathways impacted by litchi constituents were shown to stimulate proapoptotic, antiproliferative, and antimetastatic activities. Despite promising antineoplastic activities, additional research, especially in vivo and clinical studies, is necessary before litchi-derived products and phytochemicals can be used for human cancer prevention and intervention.