Characterization of P5CS gene in Calotropis procera plant from the de novo assembled transcriptome contigs of the high-throughput sequencing dataset

Proteomics and Metabolomics Analysis Reveal the Regulation Mechanism of Linoleate Isomerase Activity and Function in Propionibacterium acnes

Conjugated linoleic acid (CLA) holds significant application prospects due to its anticancer, anti-atherosclerosis, lipid-lowering, weight-loss, and growth-promoting functions. The key to its efficient production lies in optimizing the biocatalytic performance of linoleic acid isomerase (LAI). Here, we constructed a Propionibacterium acnes mutant library and screened positive mutants with high linoleate isomerase activity. The proteomics and metabolomics were used to explore the mechanism in the regulation of linoleic acid isomerase activity. High-throughput proteomics revealed 104 differentially expressed proteins unique to positive mutant strains of linoleic acid isomerase of which 57 were upregulated and 47 were downregulated. These differentially expressed proteins were primarily involved in galactose metabolism, the phosphotransferase system, starch metabolism, and sucrose metabolism. Differential metabolic pathways were mainly enriched in amino acid biosynthesis, including glutamate metabolism, the Aminoacyl-tRNA biosynthesis pathway, and the ABC transporter pathway. The upregulated metabolites include dl-valine and Acetyl coA, while the downregulated metabolites include Glutamic acid and Phosphoenolpyruvate. Overall, the activity of linoleic acid isomerase in the mutant strain was increased by the regulation of key proteins involved in galactose metabolism, sucrose metabolism, and the phosphotransferase system. This study provides a theoretical basis for the development of high-yield CLA food.

First report of triterpenes pathway in Calotropis prtocera revealed to accumulate beta-amyrin

The major reports on Calotropis procera (C. procera) indicated the importance of this plant as a resource of pharmaceutically active ingredients as well as its medical advantages. β-amyrin (BA) is a significant substance in this plant and has a pharmacological effects in some frameworks, like focal and fringe sensory system, digestive and immune systems. In this study, the impact of sunlight before and after irrigation on the BA production in C. procera is studied its pathway with involved eight key enzymes. The eight enzymes' genes were characterized and successfully submitted to NCBI; AAS (acc.no. KU997645) for α-amyrin synthase, BAS (acc.no. MW976955) for β-amyrin synthase, SE (acc.no. MW976956) for squalene epoxidase, SS (acc.no. MW976957) for squalene synthase, GPPS, (acc.no. MW976958) for geranyl pyrophosphate synthase, FPPS (acc.no. MW976959) for farnasyl pyrophosphate synthase, CAS1, (acc.no. MZ00598) for cycloartenol synthase1 and LS (acc.no. MZ005982) for lupeol synthase. qRT-PCR analysis revealed high expression levels of GPPS, FPPS, SS, SE, and BAS genes at all times specially midday. Otherwise, CAS1, LS and BAS expression levels were very low at all daylight periods. The UPLC β-amyrin data are in accordance with qRT-PCR results. This indicates that triterpenes biosynthetic pathway in C. procera is going to β-amyrin accumulation with the highest level at midday.

Light/heat effects on RNA editing in chloroplast NADH-plastoquinone oxidoreductase subunit 2 (ndhB) gene of Calotropis (Calotropis procera)

Background

RNA editing is common in terrestrial plants, especially in mitochondria and chloroplast. In the photosynthesis process, NAD dehydrogenase plays a very important role. Subunit 2 of NADH-dehydrogenase is one of the major subunits in NAD dehydrogenase complex. Using desert plant Calotropis (Calotropis procera), this study focuses on the RNA editing activity of ndhB based on light time.

Results

NdhB (NADH-dehydrogenase subunit 2) gene accession no. MK144329 was isolated from Calotropis procera genomic data (PRJNA292713). Additionally, using RNA-seq data, the cDNA of the ndhB gene of C. procera was isolated at three daylight periods, i.e., dawn (accession no. MK165161), at midday (accession no. MK165160), and pre-dusk (accession no. MK165159). Seven RNA editing sites have been found in several different positions (nucleotide no. C467, C586, C611, C737, C746, C830, and C1481) within the ndhB coding region. The rate of these alterations was deferentially edited across the three daylight periods. RNA editing rate of ndhB gene was highest at dawn, (87.5, 79.6, 78.5, 76, 68.6, 39.3, and 96.9%, respectively), less in midday (74.8, 54.1, 62.6, 47.4, 45.5, 47.4, and 93.4%, respectively), and less at pre-dusk (67, 52.6, 56.9, 40.1, 40.7, 33.2, and 90%, respectively), also all these sites were validated by qRT-PCR.

Conclusion

The differential editing of chloroplast ndhB gene across light periods may be led to a somehow relations between the RNA editing and control of photosynthesis.

Characterization and expression analysis of P5CS (Δ1-pyrroline-5-carboxylate synthase) gene in two distinct populations of the Atlantic Forest native species Eugenia uniflora L

Eugenia uniflora is an Atlantic Forest native species, occurring in contrasting edaphoclimatic environments. The identification of genes involved in response to abiotic factors is very relevant to help in understanding the processes of local adaptation. 1-Pyrroline-5-carboxylate synthetase (P5CS) is one interesting gene to study in this species since it encodes a key enzyme of proline biosynthesis, which is an osmoprotectant during abiotic stress. Applying in silico analysis, we identified one P5CS gene sequence of E. uniflora (EuniP5CS). Phylogenetic analysis, as well as, gene and protein structure investigation, revealed that EuniP5CS is a member of P5CS gene family. Plants of E. uniflora from two distinct environments (restinga and riparian forest) presented differences in the proline accumulation and P5CS expression levels under growth-controlled conditions. Both proline accumulation and gene expression level of EuniP5CS were higher in the genotypes from riparian forest than those from restinga. When these plants were submitted to drought stress, EuniP5CS gene was up-regulated in the plants from restinga, but not in those from riparian forest. These results demonstrated that EuniP5CS is involved in proline biosynthesis in this species and suggest that P5CS gene may be an interesting candidate gene in future studies to understand the processes of local adaptation in E. uniflora.

Control of β-sitosterol biosynthesis under light and watering in desert plant Calotropis procera

Most scientific studies on Calotropis procera refer to the plant as an important source of pharmaceutical compounds and its valuable benefits in medicine. One of the most important substances in this plant is the potential immunostimulant β-sitosterol (BS) that acts in improving human health. This study focused on the effects of lighting before and after irrigation on the BS accumulation pathway namely steroid biosynthesis. Studying the enzymes in BS biosynthetic pathway indicated the upregulation at dawn and predusk of the SMT2 and SMO2 genes encoding sterol methyltransferase 2 and methylsterol monooxygenase, two key enzymes in BS accumulation in C. procera. The results almost indicated no regulation at the different time points of the CYP710A gene encoding sterol 22-desaturase, an enzyme that acts in depleting β-sitosterol towards the biosynthesis of stigmasterol. RNA-Seq data was validated via quantitative RT-PCR and results were positive. The data of ultra-performance liquid chromatography-tandem mass spectrometry analysis with regard to BS accumulation also aligned with those of RNA-Seq analysis. We focused on the effects of light before and after watering on BS accumulation in C. procera. Our results show that BS accumulation is high at dawn in both dehydrated and well-watered condition. While, the BS was dramatically decrease at midday in well-watered plants. This increase/decrease in BS content is correlated with rates of expression of SMT 2 gene. This gene is a key convertor between the different branches in the cardiac glycoside biosynthesis. Accordingly, it could be suggested that BS (or one of the descendent product) may play an important role in C. procera tolerance to drought/light intensity conditions.