Genetics aspect of vitamin C (Ascorbic Acid) biosynthesis and signaling pathways in fruits and vegetables crops.

Vitamin C, also known as ascorbic acid, is an essential nutrient that plays a critical role in many physiological processes in plants and animals. In humans, vitamin C is an antioxidant, reducing agent, and cofactor in diverse chemical processes. The established role of vitamin C as an antioxidant in plants is well recognized. It neutralizes reactive oxygen species (ROS) that can cause damage to cells. Also, it plays an important role in recycling other antioxidants, such as vitamin E, which helps maintain the overall balance of the plant's antioxidant system. However, unlike plants, humans cannot synthesize ascorbic acid or vitamin C in their bodies due to the absence of an enzyme called gulonolactone oxidase. This is why humans need to obtain vitamin C through their diet. Different fruits and vegetables contain varying levels of vitamin C. The biosynthesis of vitamin C in plants occurs primarily in the chloroplasts and the endoplasmic reticulum (ER). The biosynthesis of vitamin C is a complex process regulated by various factors such as light, temperature, and plant hormones. Recent research has identified several key genes that regulate vitamin C biosynthesis, including the GLDH and GLDH genes. The expression of these genes is known to be regulated by various factors such as light, temperature, and plant hormones. Recent studies highlight vitamin C's crucial role in regulating plant stress response pathways, encompassing drought, high salinity, and oxidative stress. The key enzymes in vitamin C biosynthesis are L-galactose dehydrogenase (GLDH) and L-galactono-1, 4-lactone dehydrogenase (GLDH). Genetic studies reveal key genes like GLDH and GLDH in Vitamin C biosynthesis, offering potential for crop improvement. Genetic variations influence nutritional content through their impact on vitamin C levels. Investigating the roles of genes in stress responses provides insights for developing resilient techniques in crop growth. Some fruits and vegetables, such as oranges, lemons, and grapefruits, along with strawberries and kiwi, are rich in vitamin C. Guava. Papaya provides a boost of vitamin C and dietary fiber. At the same time, red and yellow bell peppers, broccoli, pineapple, mangoes, and kale are additional sources of this essential nutrient, promoting overall health. In this review, we will discuss a brief history of Vitamin C and its signaling and biosynthesis pathway and summarize the regulation of its content in various fruits and vegetables.

Probing Antibacterial and Anticancer Potential of Selenicereus undatus, Pistacia vera L. and Olea europaea L. against Uropathogens, MCF-7 and A2780 Cancer Cells.

Urinary tract infection is an infectious disease that requires immediate treatment. It can occur in any age group and involves both genders equally. The present study was to check the resistance of some antibiotics and to assess the antibacterial potential of three extracts of three plants against notorious bacteria involved in urinary tract infections. Along with assessing the antibacterial activity of plant extracts, we checked for the anticancer potential of these extracts against the cancer cell lines MCF-7 and A2780. Cancer is the leading cause of mortality in developed countries. Determinations of total flavonoid content, total phenolic content, total alkaloid content, total tannin content, total carotenoid content, and total steroid content were performed. The disk diffusion method was used to analyze the antibacterial activity of plant extracts. Ethanolic extract of Selenicereus undatus showed sensitivity (25-28 mm) against bacteria, whereas chloroform and hexane extracts showed resistance against all bacteria except Staphylococcus (25 mm). Ethanolic extract of Pistacia vera L. showed sensitivity (22-25 mm) against bacteria, whereas chloroform and hexane extracts showed resistance. Ethanolic extract of Olea europaea L. showed sensitivity (8-16 mm) against all bacteria except Staphylococcus, whereas chloroform and hexane extracts showed resistance. Positive controls showed variable zones of inhibition (2-60 mm), and negative control showed 0-1 mm. The antibiotic resistance was much more prominent in the case of hexane and chloroform extracts of all plants, whereas ethanolic extract showed a sensitivity of bacteria against extracts. Both cell lines, MCF-7 and A2780, displayed decreased live cells when treated with plant extracts.

A High-K+ Affinity Transporter (HKT) from Actinidia valvata Is Involved in Salt Tolerance in Kiwifruit.

Ion transport is crucial for salt tolerance in plants. Under salt stress, the high-affinity K+ transporter (HKT) family is mainly responsible for the long-distance transport of salt ions which help to reduce the deleterious effects of high concentrations of ions accumulated within plants. Kiwifruit is well known for its susceptibility to salt stress. Therefore, a current study was designed to decipher the molecular regulatory role of kiwifruit HKT members in the face of salt stress. The transcriptome data from Actinidia valvata revealed that salt stress significantly induced the expression of AvHKT1. A multiple sequence alignment analysis indicated that the AvHKT1 protein contains three conserved amino acid sites for the HKT family. According to subcellular localization analysis, the protein was primarily present in the cell membrane and nucleus. Additionally, we tested the AvHKT1 overexpression in 'Hongyang' kiwifruit, and the results showed that the transgenic lines exhibited less leaf damage and improved plant growth compared to the control plants. The transgenic lines displayed significantly higher SPAD and Fv/Fm values than the control plants. The MDA contents of transgenic lines were also lower than that of the control plants. Furthermore, the transgenic lines accumulated lower Na+ and K+ contents, proving this protein involvement in the transport of Na+ and K+ and classification as a type II HKT transporter. Further research showed that the peroxidase (POD) activity in the transgenic lines was significantly higher, indicating that the salt-induced overexpression of AvHKT1 also scavenged POD. The promoter of AvHKT1 contained phytohormone and abiotic stress-responsive cis-elements. In a nutshell, AvHKT1 improved kiwifruit tolerance to salinity by facilitating ion transport under salt stress conditions.

Role of Actin Dynamics and GhACTIN1 Gene in Cotton Fiber Development: A Prototypical Cell for Study.

Cotton crop is considered valuable for its fiber and seed oil. Cotton fiber is a single-celled outgrowth from the ovule epidermis, and it is a very dynamic cell for study. It has four distinct but overlapping developmental stages: initiation, elongation, secondary cell wall synthesis, and maturation. Among the various qualitative characteristics of cotton fiber, the important ones are the cotton fiber staple length, tensile strength, micronaire values, and fiber maturity. Actin dynamics are known to play an important role in fiber elongation and maturation. The current review gives an insight into the cotton fiber developmental stages, the qualitative traits associated with cotton fiber, and the set of genes involved in regulating these developmental stages and fiber traits. This review also highlights some prospects for how biotechnological approaches can improve cotton fiber quality.

Functional characterization of a novel, highly expressed ion-driven sugar antiporter in the thoracic muscles of Helicoverpa armigera.

Sugar transporters (STs), which mainly mediate cellular sugar exchanges, play critical physiological roles in living organisms, and they may be responsible for sugar exchanges among various insect tissues. However, the molecular and physiological functions of insect STs are largely unknown. Here, 16 STs of Helicoverpa armigera were identified. A phylogenetic analysis classified the putative HaSTs into 12 sub-families, and those identified in this study were distributed into 6 sub-families. Real-time polymerase chain reaction indicated that the 16 HaSTs had diverse tissue-specific expression levels. One transporter, HaST10, was highly expressed in thoracic muscles. A functional study using a Xenopus oocyte expression system revealed that HaST10 mediated both H+ -driven trehalose and Na+ -driven glucose antiport activities with high transport efficiency and low affinity levels. A HaST10 knockout clearly impaired the performance of H. armigera. Thus, HaST10 may participate in sugar-supply regulation and have essential physiological roles in H. armigera.

Cold stress activates disease resistance in Arabidopsis thaliana through a salicylic acid dependent pathway.

Exposure to short-term cold stress influences disease resistance by mechanisms that remain poorly characterized. The molecular basis of cold-activated immunity was therefore investigated in Arabidopsis thaliana inoculated with the bacterial pathogen Pst DC3000, using a transcriptomic analysis. Exposure to cold stress for 10 hr was sufficient to activate immunity, as well as H2 O2 accumulation and callose deposition. Transcriptome changes induced by the 10-hr cold treatment were similar to those caused by pathogen infection, including increased expression of the salicylic acid (SA) pathway marker genes, PR2 and PR5, and genes playing positive roles in defence against (hemi)-biotrophs. In contrast, transcripts encoding jasmonic acid (JA) pathway markers such as PR4 and MYC2 and transcripts with positive roles in defence against necrotrophs were less abundant following the 10-hr cold treatment. Cold-activated immunity was dependent on SA, being partially dependent on NPR1 and ICS1/SID2. In addition, transcripts encoding SA biosynthesis enzymes such as ICS2, PAL1, PAL2, and PAL4 (but not ICS1/SID2) and MES9 were more abundant, whereas GH3.5/WES1 and SOT12 transcripts that encode components involved in SA modification were less abundant following cold stress treatment. These findings show that cold stress cross-activates innate immune responses via a SA-dependent pathway.

Systems biology based meth-miRNA-mRNA regulatory network identifies metabolic imbalance and hyperactive cell cycle signaling involved in hepatocellular carcinoma onset and progression.

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the leading cause of cancer associated deaths worldwide. Independent studies have proposed altered DNA methylation pattern and aberrant microRNA (miRNA) levels leading to abnormal expression of different genes as important regulators of disease onset and progression in HCC. Here, using systems biology approaches, we aimed to integrate methylation, miRNA profiling and gene expression data into a regulatory methylation-miRNA-mRNA (meth-miRNA-mRNA) network to better understand the onset and progression of the disease. METHODS: Patients' gene methylation, miRNA expression and gene expression data were retrieved from the NCBI GEO and TCGA databases. Differentially methylated genes, and differentially expressed miRNAs and genes were identified by comparing respective patients' data using two tailed Student's t-test. Functional annotation and pathway enrichment, miRNA-mRNA inverse pairing and gene set enrichment analyses (GSEA) were performed using DAVID, miRDIP v4.1 and GSEA tools respectively. meth-miRNA-mRNA network was constructed using Cytoscape v3.5.1. Kaplan-Meier survival analyses were performed using R script and significance was calculated by Log-rank (Mantel-Cox) test. RESULTS: We identified differentially expressed mRNAs, miRNAs, and differentially methylated genes in HCC as compared to normal adjacent tissues by analyzing gene expression, miRNA expression, and methylation profiling data of HCC patients and integrated top miRNAs along with their mRNA targets and their methylation profile into a regulatory meth-miRNA-mRNA network using systems biology approach. Pathway enrichment analyses of identified genes revealed suppressed metabolic pathways and hyperactive cell cycle signaling as key features of HCC onset and progression which we validated in 10 different HCC patients' datasets. Next, we confirmed the inverse correlation between gene methylation and its expression, and between miRNA and its targets' expression in various datasets. Furthermore, we validated the clinical significance of identified methylation, miRNA and mRNA signatures by checking their association with clinical features and survival of HCC patients. CONCLUSIONS: Overall, we suggest that simultaneous (1) reversal of hyper-methylation and/or oncogenic miRNA driven suppression of genes involved in metabolic pathways, and (2) induction of hyper-methylation and/or tumor suppressor miRNA driven suppression of genes involved in cell cycle signaling have potential of inhibiting disease aggressiveness, and predicting good survival in HCC.

Novel tumor suppressor SPRYD4 inhibits tumor progression in hepatocellular carcinoma by inducing apoptotic cell death.

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-associated deaths worldwide. Although recent studies have proposed different biomarkers for HCC progression and therapy resistance, a better understanding of the molecular mechanisms underlying HCC progression and recurrence, as well as the identification of molecular markers with a higher diagnostic accuracy, are necessary for the development of more effective clinical management strategies. Here, we aimed to identify novel players in HCC progression. METHODS: SPRYD4 mRNA and protein expression analyses were carried out on a normal liver-derived cell line (HL-7702) and four HCC-derived cell lines (HepG2, SMMC7721, Huh-7, BEL-7402) using qRT-PCR and Western blotting, respectively. Cell proliferation Cell Counting Kit-8 (CCK-8) assays, protein expression analyses for apoptosis markers using Western blotting, and Caspase-Glo 3/7 apoptosis assays were carried out on the four HCC-derived cell lines. Expression comparison, functional annotation, gene set enrichment, correlation and survival analyses were carried out on patient data retrieved from the NCBI Gene module, the NCBI GEO database and the TCGA database. RESULTS: Through a meta-analysis we found that the expression of SPRYD4 was downregulated in primary HCC tissues compared to non-tumor tissues. We also found that the expression of SPRYD4 was downregulated in HCC-derived cells compared to normal liver-derived cells. Subsequently, we found that the expression of SPRYD4 was inversely correlated with a gene signature associated with HCC cell proliferation. Exogenous SPRYD4 expression was found to inhibit HCC cell proliferation by inducing apoptotic cell death. We also found that SPRYD4 expression was associated with a good prognosis and that its expression became downregulated when HCCs progressed towards more aggressive stages and higher grades. Finally, we found that SPRYD4 expression may serve as a biomarker for a good overall and relapse-free survival in HCC patients. CONCLUSIONS: Our data indicate that a decreased SPRYD4 expression may serve as an independent predictor for a poor prognosis in patients with HCC and that increased SPRYD4 expression may reduce HCC growth and progression through the induction of apoptotic cell death, thereby providing a potential therapeutic target.

HISTONE DEACETYLASE 6 represses pathogen defence responses in Arabidopsis thaliana.

Plant defence mechanisms are suppressed in the absence of pathogen attack to prevent wasted energy and growth inhibition. However, how defence responses are repressed is not well understood. Histone deacetylase 6 (HDA6) is a negative regulator of gene expression, and its role in pathogen defence response in plants is not known. In this study, a novel allele of hda6 (designated as shi5) with spontaneous defence response was isolated from a forward genetics screening in Arabidopsis. The shi5 mutant exhibited increased resistance to hemibiotrophic bacterial pathogen Pst DC3000, constitutively activated expression of pathogen-responsive genes including PR1, PR2, etc. and increased histone acetylation levels at the promoters of most tested genes that were upregulated in shi5. In both wild type and shi5 plants, the expression and histone acetylation of these genes were upregulated by pathogen infection. HDA6 was found to bind to the promoters of these genes under both normal growth conditions and pathogen infection. Our research suggests that HDA6 is a general repressor of pathogen defence response and plays important roles in inhibiting and modulating the expression of pathogen-responsive genes in Arabidopsis.

[Forest soil organic carbon density and its distribution characteristics along an altitudinal gradient in Lushan Mountains of China].

To understand the spatial distribution characteristics of organic carbon in northern subtropical forest soils along an altitudinal gradient in Lushan Mountains of China, six and five sampling plots with a 200-m interval of elevation and covered by different vegetation types were installed on the southern and northern slopes, respectively in July-August in 2010 to collect soil profiles, with the soil thickness, bulk density, organic carbon content, and organic carbon density of 0-10 cm, 10-20 cm, 20-30 cm, 30-40 cm, and >40 cm layers measured. The soil organic carbon density was significantly affected by altitude and slope. On northern slope, soil organic carbon content increased with increasing altitude, and had significant negative correlations with soil bulk density and pH value. On southern slope, soil organic carbon content had no obvious variation pattern along the altitudinal gradient and had less correlation with soil bulk density and pH value, but soil organic carbon density decreased with increasing soil depth. The soil organic carbon density on northern and southern slopes was within the range of 7.07 - 10. 34 kg x m(-2) and 6.03 - 12.89 kg x m(-2), respectively. The larger variation of soil organic carbon density along altitudinal gradient and soil depth on southern slope suggested that the destruction of original vegetation and the establishment of forest plantation could be one of the important factors affecting the spatial distribution of soil organic carbon.