A hybrid RSM-BPNN-GA approach for optimizing ultrasound-assisted deep eutectic solvents extraction conditions for Mesona chinensis benth. and investigation of the extraction mechanism.

Mesona chinensis Benth (MCB) is the source of the most commonly consumed herbal beverage in Southeast Asia and China and is thus an economically important agricultural plant. Therefore, optimal extraction and production procedures have significant commercial value. Currently, in terms of green chemistry, researchers are investigating the use of greener solvents and innovative extraction techniques to increase extract yields. This study represents the first investigation of the optimal conditions for ultrasound-assisted deep eutectic solvent (DES) extraction from MCB. The major factors influencing ultrasound-assisted DESs were optimized using the response surface methodcentral-genetic algorithm-back propagation neural networks. This model demonstrated superior predictability and accuracy compared to the RSM model. Various types of DESs were used for the extraction of MCB constituents, with choline chloride-ethylene glycol resulting in the highest yield. The optimal conditions for maximal extraction were the use of choline chloride-ethylene glycol (1:4) as the solvent with a 40% water content, an extraction duration of 60 min at 60°C, and maintaining a leaf-to-solvent ratio of 20 mL/g. Noticeable enhancements in Van der Waals forces and more robust interactions between DESs and the target chemicals were observed relative to those seen with ethanol (70%, v/v) or water. This investigation not only introduced an environmentally friendly approach for highly efficient extraction from MCB but also identified the mechanisms underlying the improved extraction efficacy. These findings have the potential to contribute to the broader utilization of MCB and provide valuable insights into the extraction mechanisms utilizing deep eutectic solvents. PRACTICAL APPLICATION: This work describes an efficient and green ultrasound-assisted deep eutectic solvent (DES) method for Mesona chinensis Benth (MCB) extraction. Molecular dynamics was used to examine the intermolecular interactions between the solvent and the extracted compounds. It is anticipated that green and environmentally friendly solvents, such as DESs, will be used in further research on foods and their bioactive components. With the development of the herbal tea industry, new products made of MCB are becoming increasingly popular, thus gradually making it a research hotspot.

Hypolipidemic Effects of Mesona chinensis Benth Polysaccharides with Different Structures and Molecular Weights.

Four novel Mesona chinensis Benth polysaccharides were isolated using aqueous alcohol precipitation. Their molecular weights were determined using high-performance gel permeation chromatography: MA1 (2.3 kDa), MA2 (80.5 kDa), MA3 (180.9 kDa), and MA4 (635.2 kDa), and their compositions were analyzed using GC-MS. The polysaccharides were mainly D-glucose, D-galactose, L-Rhamnose, D-arabinose, D-xylose, and D-mannose. The structural characteristics were further analyzed using infrared spectrophotometry and were identified as a type of pyrrhic sugar. An insulin-induced insulin resistance model of HepG2 cells and oleic acid-induced fat accumulation model of insulin were established to evaluate the hypolipidemic effects. Three Bacteroides spp. [Bacteroides thetaiotaomicron (BT), B. ovatus (BO), and B. cellulosilyticus (BC)] that were negatively correlated with lipid-lowering activity were used to evaluate the lipid-lowering activity of polysaccharides. The Bacteroides metabolites of MA1 and MA2 exhibited hypolipidemic effects and antioxidant activities and could potentially be used as lipid-lowering supplements.

Preparation technologies, structural features, and biological activities of polysaccharides from Mesona chinensis Benth.: A review.

ETHNOPHARMACOLOGICAL RELEVANCE: Mesona chinensis Benth. (or Platostoma palustre (Blume) A. J. Paton) is an important medicinal and edible plant also known as the Hsian-tsao in China and Southeast Asian countries. It is cold in nature and sweet in taste, with the effects of clearing heat, relieving heatstroke and diuretic, and traditionally used to treat heatstroke, erysipelas, hypertension, joint pain and other diseases in folk medicine. It is also a popular supplement with the function of detoxifying and heat-clearing use in Asia. It is used to be processed into the popular tea, Bean jelly, and so on. Published studies have demonstrated that polysaccharides from M. chinensis (MCPs) are one of the principal bioactive ingredients with a variety of health-promoting effects in the prevention and treatment of diseases, including antioxidant, immunomodulation, anti-inflammatory, hepatoprotective, anti-tumor, hypoglycemic, regulation of gut microbiota, and other pharmacological properties. AIM OF THE REVIEW: This review aims to compile the extraction and purification methods, structural characteristics, pharmacological activities including the mechanism of action of MCPs, and to further understand the applications of M. chinensis in order to lay the foundation for the development of MCPs. MATERIALS AND METHODS: By inputting the search term "Mesona chinensis polysaccharides", relevant research information was obtained from databases such as PubMed, Google Scholar, Web of Science, and China National Knowledge Infrastructure (CNKI). RESULTS: More than 40 polysaccharides have been extracted from M. chinensis, different extraction and purification methods have been described, as well as the structural features and pharmacological activities of MCPs have been systematically reviewed. Polysaccharides, as important components of M. chinensis, were mainly extracted by methods such as hot water dipping method, hot alkali extraction method, enzyme-assisted extraction method and ultrasonic-assisted extraction method, subsequently obtained by decolorization, deproteinization, removal of other small molecules and separation on various chromatographic columns. The chemical composition and structure of MCPs show diversity and have a variety of pharmacological activities, including antioxidant, immunomodulation, anti-inflammatory, hepatoprotective, anti-tumor, hypoglycemic, regulation of gut microbiota, and so on. CONCLUSIONS: This article systematically reviews the research progress of MCPs in terms of extraction and purification, structural characteristics, rheological gel properties, pharmacological properties, and safety assessment. The potentials and roles of M. chinensis in the field of medicine, functional food, and materials are further highlighted to provide references and bases for the high-value processing and utilization of MCPs.

Structural properties and adsorption capacities of Mesona chinensis Benth residues dietary fiber prepared by cellulase treatment assisted by Aspergillus niger or Trichoderma reesei.

The effects of enzyme hydrolysis treatment, Aspergillus niger fermentation treatment, Trichoderma reesei fermentation treatment, Aspergillus niger-enzyme hydrolysis treatment and Trichoderma reesei-enzyme hydrolysis treatment on structural properties and adsorption capacities of soluble dietary fiber from Mesona chinensis Benth residues were evaluated and compared. The Aspergillus niger-enzyme hydrolysis treatment sample possessed more diverse structure, lower crystallinity and thermal stability than other modified samples. Meanwhile, it also observed the highest soluble dietary fiber yield (20.76 ± 0.31 %), water-holding capacity and glucose adsorption capacity (38.03 ± 0.28 mg/g). The Aspergillus niger fermentation treatment sample generated a high oil-holding capacity, nitrite ion adsorption capacity (181.84 ± 6.67 ug/g), cholesterol adsorption capacity (16.40 ± 0.37 mg/g) and sodium cholate adsorption capacity (94.80 ± 1.41 mg/g). Additionally, different monosaccharide composition was exhibited due to diverse extraction methods. Our finding revealed that these two modification methods could effectively enhance the economic value of Mesona chinensis Benth residues.

The effects of Mesona chinensis Benth gum on the pasting, rheological, and microstructure properties of different types of starches.

The effect of Mesona chinensis Benth gum (MCG) on pasting, rheological and texture properties of different types of starches (tubers, cereals, and beans) were investigated. Pasting results showed that the pasting temperatures (PT) of native cereal and beans starch were higher, and MCG decreased the PT of starch granules by competing water with starch granules for water. MCG increased the peak viscosity and breakdown viscosity of native starches except potato starch, and effectively promoted the short-term retrogradation of all kinds of starches. Rheological results also revealed MCG increased apparent viscosity and dynamic modulus of native starch gels, given that the compacter network structures could be formed after adding MCG. The compacter network structures also contribute to the enhancement of gel strength and hardness, and the decreased spin relaxation time of starch gels. The information provided in this paper could help people to understand the different effects of MCG on the various starch, which had certain significance for starch-MCG product development.

Corrigendum: Hsian-Tsao (Mesona chinensis Benth.) extract improves the thermal tolerance of Drosophila melanogaster.

[This corrects the article DOI: 10.3389/fnut.2022.819319.].

Mesona chinensis polysaccharide accelerates the short-term retrogradation of debranched waxy corn starch.

The effect of non-starch polysaccharides on the structural and functional properties of native starch have been extensively studied. However, the effect of non-starch polysaccharides on the structural characteristics of debranched starch, a kind of enzymatic modified starch, remains unclear. The aim of this study is to investigate the effects of Mesona chinensis polysaccharide (MP) on starch retrogradation and structural properties of debranched waxy corn starch (DWS). The results showed that only appropriate addition of MP (0.5 or 1%) can effectively promote the short-term retrogradation of DWS, while excessive MP (3 or 5%) had a negative effect. Gel hardness results revealed that the short-term retrogradation (24 h) of DWS could be divided into two phases. The retrogradation of DWS-MP gels mainly occurred at first stage (0-4 h), which was demonstrated by the rapid increase of gel hardness and relative crystallinity in this stage. In the second stage (4-24 h), DWS-MP gels were more likely to undergo the aggregation of starch granules as proved by SEM and particle size results. The degree of short-range ordered decreased during the total retrogradation stage. Overall, this work aims to provide an insight into the effect of non-starch polysaccharides on the short-term retrogradation of DWS.

The Antioxidant and Hypolipidemic Effects of Mesona Chinensis Benth Extracts.

In this study, the antioxidant and hypolipidemic effects of Mesona Chinensis Benth (MCB) extracts were evaluated. Seven fractions (F0, F10, F20, F30, F40, F50 and MTF) were obtained from the MCB ethanol extracts. Compared to the commercial antioxidants (vitamin C), MTF and F30 exhibited higher antioxidant activities in the antiradical activity test and the FRAP assay. The half-inhibition concentration (IC50) for MTF and F30 were 5.323 µg/mL and 5.278 µg/mL, respectively. MTF at 200 µg/mL significantly decreased the accumulation of TG in oleic acid (OA)-induced HepG2 cells and reversed the inhibitory effect of Compound C on AMPK (MTF and F30 significantly increased the glucose utilization of insulin-induced HepG2 cells). In addition, the components of MTF were identified by HPLC-MS, which were caffeic acid, quercetin 3-O-galactoside, isoquercetin, astragalin, rosmarinic acid, aromadendrin-3-O-rutinoside, rosmarinic acid-3-O-glucoside and kaempferol-7-O-glucoside. Through statistical correlations by Simca P software, it was found that the main antioxidant and hypolipidemic components of MCB might be caffeic acid, kaempferol-7-O-glucoside, rosmarinic acid-3-O-glucoside and aromadendrin-3-O-rutinoside, which may play important roles in the AMPK pathway. MTF and F30 in MCB could be potential health products for the treatment of hyperlipidemia.

Mesona chinensis Benth Polysaccharides Alleviate DSS-Induced Ulcerative Colitis via Inhibiting of TLR4/MAPK/NF-κB Signaling Pathways and Modulating Intestinal Microbiota.

SCOPE: Ulcerative colitis (UC) is a severe disease of the intestinal tract. To investigate the role of TLR4/Mitogen-activated protein kinase (MAPK)/Nuclear factor kappa-B(NF-κB) pathways and intestinal flora in UC, and the protective mechanisms of Mesona chinensis Benth polysaccharides (MBP), potential therapeutic agents due to their diabetes-relieving, cancer-suppressing, and immunomodulatory properties. METHODS AND RESULTS: A dextran sulfate sodium (DSS)-induced mouse colitis model is used for experiments; the histopathology, immunohistochemistry, and Western blotting's results suggest that MBP can alleviate the colitis symptoms, inhibits the overproduction of TNF-α, IL-1ß, promote IL-10, reduces myeloperoxidase activity, and alleviates the inflammatory response probably by inhibiting the activation of TLR4/MAPK/NF-κB pathways. Furthermore, MBP improvs the ratio of Bcl-2/BAX, maintains the intestinal integrity by promoting the levels of zonulin occludin-1 (ZO-1), occluding and mucin mucin-2 (MUC-2), reduces the levels of endotoxin (ET), lipopolysaccharide binding protein (LBP) in serum, and oxidative stress in liver. Moreover, using 16S rRNA Gene Sequencing analysis, MBP regulates gut microbiota by decreasing the abundances of Helicobacter and Prevotella and increasing the abundances of Lactobacillus and Coprococcus, reverses microbiota dysbiosis caused by DSS. CONCLUSION: These findings confirm the anti-inflammatory effects of MBP, restoration of the intestinal barrier and intestinal flora, and have therapeutic potential to attenuate the development of UC.

RNA-seq based elucidation of mechanism underlying Mesona chinensis Benth polysaccharide protected H2O2-induced oxidative damage in L02 cells.

The homeostasis of oxidative stress is vital to the physiological behavior of normal human or animal cells, and its underlying molecular mechanism is contributed to the exploitation of functional food used in chronic diseases. Thus, the mechanism of protective effect of Mesona chinensis Benth polysaccharides (MP) in H2O2-induced oxidative damage was investigated thoroughly. Results showed that MP significantly recovered cell viability and elevated activity of antioxidant enzymes. Based on RNA-seq analysis, we found that MP mainly exhibited protection effect thought regulation mitochondrial function and affect PI3K and MAPK signaling pathways. Furthermore, we found that MP affected mitochondrial function via improved mitochondrial membrane potential (MMP), thereby elevating ATP biosynthesis. Moreover, western blot analysis verified that MP mitigated H2O2-induced oxidative damage via PI3K/Akt, MAPK, and mitochondrial-mediated apoptosis signaling pathway. These findings provided a possible mechanism for MP on preventing and treating chronic diseases involved in oxidative stress, which was a benefit for development of functional food.

Physicochemical structure and functional properties of soluble dietary fibers obtained by different modification methods from Mesona chinensis Benth. residue.

Alkaline hydrogen peroxide (AHP), high-temperature cooking combined with ultrasonic (HTCU) and high-temperature cooking combined with complex enzyme hydrolysis (HTCE) were used to modify soluble dietary fiber (SDF) in Mesona chinensis Benth. residue (MCBR), then the structural and in vitro functional properties of A-SDF, HU-SDF and HE-SDF were investigated. Results showed that the three treatments significantly increased the yield of SDF. Scanning electron microscopy, FT-IR, monosaccharide composition, X-ray diffraction, molecular weight distribution and thermal stability analysis were employed to determine the structural changes. Compared with the control SDF (CK-SDF), HE-SDF and HU-SDF had looser and more porous microstructure, as well as lower crystallinity. In contrast to HE-SDF and HU-SDF, A-SDF exhibited a dense wavy microstructure, and elevated crystallinity and thermal stability. In addition, the monosaccharide composition and molecular weight of HU-SDF, HE-SDF and A-SDF were significantly altered as compared to CK-SDF. Moreover, the functional properties of HE-SDF and HU-SDF, including water holding capacity (WHC), oil holding capacity (OHC), glucose adsorption capacity (GAC), α-amylase activity inhibition ratio (α-AAIR), cholesterol adsorption capacity (CAC) and nitrite ion adsorption capacity (NIAC), were significantly higher than those of CK-SDF. However, the dense structure and high crystallinity of A-SDF resulted in a significantly lower GAC and NIAC than that of CK-SDF, with only WHC and α-AAIR being improved. Overall, this study showed that HTCU and HTCE could be used as ideal modification methods for MCBR SDF, HE-SDF and HU-SDF have potential as functional additives in food.

Hsian-Tsao (Mesona chinensis Benth.) Extract Improves the Thermal Tolerance of Drosophila melanogaster.

Global warming has prompted scientific communities to consider how to alleviate thermal stress in humans and animals. The present study assessed the supplementation of hsian-tsao extract (HTE) on thermal stress in Drosophila melanogaster and preliminarily explicated its possible physiological and molecular mechanisms. Our results indicated that the lethal time for 50% of female flies fed on HTE was significantly longer than that of male flies at the same heat stress temperature. Under thermal stress, the survival time of females was remarkably increased in the HTE addition groups compared to the non-addition group. Thermal hardening by acute exposure to 36°C for 30 min (9:00 to 9:30 a.m.) every day could significantly prolong the longevity of females. Without thermal hardening, HTE increased the antioxidant capacity of females under heat stress, accompanied by an increment of catalase (CAT) activity, and the inhibition for hydroxyl radicals (OH⋅) and superoxide anions (⋅O2 -). Superoxide dismutase (SOD) activity and the inhibition for ⋅O2 - was significantly affected by thermal hardening in the non-HTE addition groups, and significant differences were shown in CAT and SOD activities, and the inhibition for ⋅O2 - among groups with thermal hardening. After heat exposure, heat shock protein 70 (Hsp70) was only up-regulated in the group with high levels of added HTE compared with the group without and this was similar in the thermal hardening group. It was concluded that the heat stress-relieving ability of HTE might be partly due to the enhancement of enzymatic activities of SOD and CAT, and the inhibition for OH⋅ and ⋅O2 -. However, the expression levels of Hsp70 were not well related to thermal tolerance or heat survival.

Characteristics and comparative analysis of Mesona chinensis Benth chloroplast genome reveals DNA barcode regions for species identification.

Mesona chinensis Benth (MCB) is an important medicinal and edible plant in Southern China and Southeast Asian countries. Chloroplast (cp) genome is usually used for plant phylogeny, species identification, and chloroplast genetic engineering. To characterize the cp genome and determine the evolutionary position and perform the genetic diversity analysis of MCB, we sequence and characterize the MCB cp genome. The results show that the cp genome of MCB is a single circular molecule with a length of 152,635 bp. It is a typical quadripartite structure, comprising a large single-copy region (LSC, 83,514 bp) and a small single-copy region (SSC, 17,751 bp) separated by two inverted repeat regions (IRs, 51,370 bp). It encodes 129 unique genes, including 84 protein-coding genes (PCGs), 37 transfer RNAs (tRNAs), and 8 ribosomal RNAs (rRNAs). Altogether 127 simple sequence repeats (SSRs) are identified in the MCB cp genome with 86.61% of mononucleotide repeats. Phylogenetic analysis reveals that MCB is most closely related to Ocimum basilicum based on the whole cp genomes. Several highly divergent regions are found, such as trnH_psbA, rps16_trnQ, trnS_trnG, trnE_trnT, psaA_ycf3, rpl32_trnL, ccsA_ndhD, ndhG_ndhI, and rps15_ycf1, which can be proposed for use as DNA barcode regions. Genetic diversity analysis unveils a relatively narrow genetic basis of MCB germplasm resources. Therefore, the innovative breeding of MCB is very urgent and necessary in future research.

Changes in polysaccharides structure and bioactivity during Mesona chinensis Benth storage.

Mesona chinensis Benth has been consumed as a functional food for many years. It is widely believed that storage times affect its health benefits. In this study, Mesona chinensis Benth polysaccharides with two different storage times (fresh and storage for 1 year) were prepared, namely, FMP and AMP. The physicochemical properties and bioactivity were comparatively assessed. Results indicated that FMP was mainly composed of galacturonic acid, galactose, and glucose with a molecular weight of 44.39 kDa. AMP was composed of galacturonic acid, galactose, and fructose with a molecular weight of 64.34 kDa. However, the principal structural characteristics of polysaccharides remained stable. Furthermore, assays of antioxidant activity showed that Mesona chinensis Benth polysaccharide had an antioxidant effect against DPPH radical, ABTS radical cation, among which FMP was stronger. Additionally, flow cytometry indicated that the apoptosis rate of FMP and AMP on HepG2 tumor cells was 22.50 ± 1.25% and 15.49 ± 1.30%, respectively. In general, antioxidant and antitumor activities of Mesona chinensis Benth polysaccharides were decreased as the storage for 1 year. The change of physicochemical properties was responsible for the enhanced bioactivities. These results explained how polysaccharides contributed to the decreased health benefits of Mesona chinensis Benth during storage.

Physio-Morphological, Biochemical and Transcriptomic Analyses Provide Insights Into Drought Stress Responses in Mesona chinensis Benth.

Drought stress affects the normal growth and development of Mesona chinensis Benth (MCB), which is an important medicinal and edible plant in China. To investigate the physiological and molecular mechanisms of drought resistance in MCB, different concentrations of polyethylene glycol 6000 (PEG6000) (0, 5, 10, and 15%) were used to simulate drought conditions in this study. Results showed that the growth of MCB was significantly limited under drought stress conditions. Drought stress induced the increases in the contents of Chla, Chlb, Chla + b, soluble protein, soluble sugar, and soluble pectin and the activities of superoxide dismutase (SOD), catalase (CAT), total antioxidant capacity (TAC), hydrogen peroxide (H2O2), and malondialdehyde (MDA). Transcriptome analysis revealed 3,494 differentially expressed genes (DEGs) (1,961 up-regulated and 1,533 down-regulated) between the control and 15% PEG6000 treatments. These DEGs were identified to be involved in the 10 metabolic pathways, including "plant hormone signal transduction," "brassinosteroid biosynthesis," "plant-pathogen interaction," "MAPK signaling pathway-plant," "starch and sucrose metabolism," "pentose and glucuronate interconversions," "phenylpropanoid biosynthesis," "galactose metabolism," "monoterpenoid biosynthesis," and "ribosome." In addition, transcription factors (TFs) analysis showed 8 out of 204 TFs, TRINITY_DN3232_c0_g1 [ABA-responsive element (ABRE)-binding transcription factor1, AREB1], TRINITY_DN4161_c0_g1 (auxin response factor, ARF), TRINITY_DN3183_c0_g2 (abscisic acid-insensitive 5-like protein, ABI5), TRINITY_DN28414_c0_g2 (ethylene-responsive transcription factor ERF1b, ERF1b), TRINITY_DN9557_c0_g1 (phytochrome-interacting factor, PIF3), TRINITY_DN11435_c1_g1, TRINITY_DN2608_c0_g1, and TRINITY_DN6742_c0_g1, were closely related to the "plant hormone signal transduction" pathway. Taken together, it was inferred that these pathways and TFs might play important roles in response to drought stress in MCB. The current study provided important information for MCB drought resistance breeding in the future.

Mitochondrial genome characteristics and phylogenetic analysis of the medicinal and edible plant Mesona chinensis Benth.

Mesona chinensis Benth (MCB) (or Platostoma palustre or Platostoma chinense) is an important edible and medicinal plant in China. However, the mitochondrial genome (mitogenome, or mtDNA) of MCB has not been characterized or reported yet. In this study, we first sequenced and characterized the complete mitogenome of MCB. The MCB mitogenome was 494,599 bp in length and encoded 59 genes containing 37 protein-coding genes (PCGs), 19 tRNAs, and 3 rRNAs. Gene transfer analysis revealed that a total of 12 transfer segments with more than 93% identity (total length of 25,427 bp) were detected in the MCB mitogenome. Simple sequence repeats (SSR) analysis showed that 212 simple sequence repeats (SSR) were identified. Repeat sequence analysis revealed 305 repeat sequences (158 forward and 147 palindromic repeats) ranging from 30 bp to 48,383 bp and the 30-39 bp repeats were the majority type. Relative synonymous codon usage (RSCU) analysis uncovered that in total, 9,947 codons were encoding the protein-coding genes (PCGs). Serine (909, 9.1%) and leucine (879, 8.8%) were the two most abundant amino acids, while terminator (32, .3%) was the least abundant amino acid. Ka/Ks analysis indicated that almost all genes were subject to purification selection, except ccmB. Analysis of Lamiaceae mitogenomes constitution revealed that atpB and atpE were unique to the Rotheca serrata and Salvia miltiorrhiza mitogenomes. mttB gene loss was unique to the Boea hygrometrica mitogenome. The core fragments of the Lamiaceae mitogenomes harbored a higher GC content than the specific and variable fragments. In addition, phylogenetic analysis revealed that MCB was closely related to Salvia miltiorrhiza based on the mitogenomes. The current study provided valuable genomic resources for understanding and utilizing this important medicinal plant in the future.

Identification of Differentially Expressed Genes and Pathways Involved in Growth and Development of Mesona chinensis Benth Under Red- and Blue-Light Conditions.

Mesona chinensis Benth (MCB) is an important Chinese herbal medicine. The plant factories might be one of the ways to solve the shortage of MCB supply. In this study, the MCB seedlings were treated under the red (R) and blue (B) lights in the plant factory. Results showed that the red light promoted the growth and development of MCB in comparison with the blue light. Under the red-light condition, the biomass, plant height, and root characteristics were significantly higher than those under blue-light condition, while the soil and plant analyzer development (SPAD) under the red-light treatment was significantly lower than that under the blue-light treatment. Red light also significantly promoted the content of soluble sugar and pectin of MCB compared with blue light. Transcriptome analysis showed that a total of 4,165 differentially expressed genes (DEGs) were detected including 2,034 upregulated and 2,131 downregulated. Of these, 1,112 DEGs including 410 upregulated and 702 downregulated genes were associated with 111 pathways. Moreover, a total of 8,723 differentially expressed transcription factors (TFs) were identified in R vs. B, and these TFs were distributed in 56 gene families. Metabonomic results revealed that a total of 184 metabolites and 99 differentially expressed metabolites (DEMs) (42 upregulated and 57 downregulated) were identified in the red- and blue-light treatments. Integrative analysis of transcriptome and metabolome unveiled that a total of 24 pathways included 70 compounds (metabolites) and were associated with 28 unigenes. In particular, these pathways included starch and sucrose metabolism, phenylpropanoid biosynthesis, cysteine and methionine metabolism, glycolysis/gluconeogenesis, and pentose and glucuronate interconversions. The unigenes included asparagine synthetase (AS), thymidine kinase (TK), alpha, alpha-trehalose-phosphate synthase (TPS), phosphatase IMPL1 (IMPL1), dihydroflavonol 4-reductase (D4R), and 4-coumarate-CoA ligase-like 6 (4CL6), bifunctional aspartokinase-homoserine dehydrogenase 1 (thrA), and abscisic acid 8'-hydroxylase 2 isoform X1 (ABA8). It was indicated that these pathways and genes might play important roles in the growth and development of MCB. This study laid a foundation for the future research of MCB.

Analysis of codon usage bias and evolution in the chloroplast genome of Mesona chinensis Benth.

Mesona chinensis Benth (MCB) is one of the main economic crops in tropical and subtropical areas. To understand the codon usage bias (CUB) in M. chinensis Benth, chloroplast genome is essential to study its genetic law, molecular phylogenetic relationships, and exogenous gene expression. Results showed that the GC content of 53 CDS sequences was 37.95%, and GC1, GC2, and GC3 content were 46.02%, 38.26%, and 29.85%, respectively. The general GC content order was GC1>GC2>GC3. Moreover, the majority of genes had an effective number of codon (ENC) value greater than 40, except ndhE, rps8, and rps18. Correlation analysis results revealed that the GC content was significantly correlated with GC1, GC2, GC3, and ENC. Neutrality plot analysis, ENC-plot analysis, and PR2-plot analysis presented that the CUB of M. chinensis Benth chloroplast genome was mainly affected by mutation and selection. In addition, GGG, GCA, and TCC were found to be the optimal codons. Furthermore, results of cluster analysis and evolutionary tree showed that M. chinensis Benth was closely related to Ocimum basilicum, indicating that there was a certain correlation between the CUB of the chloroplast gene and the genetic relationship of plant species. Overall, the study on the CUB of chloroplast genome laid a basis for genetic modification and phylogenetic research of M. chinensis Benth chloroplast genome.

The role of alkali in sweet potato starch-Mesona chinensis Benth polysaccharide gels: Gelation, rheological and structural properties.

According to the Chinese traditional black jelly production process, a critical step to ensure the quality of jelly is to add alkali to it. In this study, the effects of sodium carbonate (Na2CO3) and sodium bicarbonate (NaHCO3) on the pasting, rheological, textural, and structural properties of sweet potato starch (SPS)-Mesona chinensis Benth polysaccharide (MCP) gels were evaluated. Adding Na2CO3 at low concentration reduced the final viscosity (FV) of SPS-MCP gels, whereas adding it at a high concentration increased the FV. Adding NaHCO3 can increase the FV of SPS-MCP gels in a concentration-dependent manner. Rheological results indicated that adding NaHCO3 at a low concentration decreased the storage modulus of SPS-MCP gels, whereas adding it at a high concentration increased the storage modulus. The storage modulus of SPS-MCP gels increased with increasing concentration of NaHCO3. The addition of Na2CO3 and NaHCO3 improved the textural properties of SPS-MCP gels and decreased the water mobility. Infrared results indicated that adding alkali can enhance the hydrogen bonding between SPS and MCP. Scanning electron microscopy results suggested that alkali can reduce the size of gels, and make the structure more compact.

Interaction between rice starch and Mesona chinensis Benth polysaccharide gels: Pasting and gelling properties.

Interactions between starch and non-starch polysaccharides are very important for predicting and controlling the structure and function of starch-.based products. In this study, the effects of Mesona chinensis Benth polysaccharide (MCP) on the pasting, rheological, structural, and water mobility properties of rice starch (RS)-MCP gels were evaluated. Results indicated that MCP can increase the pasting viscosity, and gel properties of RS-MCP gels. Rheological results showed that RS-MCP gels exhibited shear-thinning behavior and that MCP can enhance the viscoelasticity of RS-MCP gels. Fourier-transform infrared spectra results indicated no covalent interaction between RS and MCP, and MCP could increase the degree of short-range order of RS-MCP gels. MCP also enhanced the water-retention capacity of RS-MCP gels. Scanning electron microscopy results suggested that MCP could decrease the pore sizes of RS gels and the microstructure of RS gels became more ordered at 0.1 % concentration of MCP. The results suggested that the amylose and MCP molecules interacted through hydrogen bonds and electrostatic forces, which enhanced the gelling properties of RS-MCP gels. Overall, this study shows the potential applications of MCP, and also provides the theoretical basis of interactions in starch-hydrocolloids systems.