Identification of PP2Cs in six rosaceae species highlights RcPP2C24 as a negative regulator in rose drought tolerance.

Drought is a major environmental stress that limits plant growth, so it's important to identify drought-responsive genes to understand the mechanism of drought response and breed drought-tolerant roses. Protein phosphatase 2C (PP2C) plays a crucial role in plant abiotic stress response. In this study, we identified 412 putative PP2Cs from six Rosaceae species. These genes were divided into twelve clades, with clade A containing the largest number of PP2Cs (14.1%). Clade A PP2Cs are known for their important role in ABA-mediated drought stress response; therefore, the analysis focused on these specific genes. Conserved motif analysis revealed that clade A PP2Cs in these six Rosaceae species shared conserved C-terminal catalytic domains. Collinearity analysis indicated that segmental duplication events played a significant role in the evolution of clade A PP2Cs in Rosaceae. Analysis of the expression of 11 clade A RcPP2Cs showed that approximately 60% of these genes responded to drought, high temperature, and salt stress. Among them, RcPP2C24 exhibited the highest responsiveness to both drought and ABA. Furthermore, overexpression of RcPP2C24 significantly reduced drought tolerance in transgenic tobacco by increasing stomatal aperture after exposure to drought stress. The transient overexpression of RcPP2C24 weakened the dehydration tolerance of rose petal discs, while its silencing increased their dehydration tolerance. In summary, our study identified PP2Cs in six Rosaceae species and highlighted the negative role of RcPP2C24 on rose's drought tolerance by inhibiting stomatal closure. Our findings provide valuable insights into understanding the mechanism behind rose's response to drought.

Comparative metabolomics profiling reveals the unique bioactive compounds and astringent taste formation of rosehips.

Rosehips are a prominent source of numerous bioactive compounds. However, despite their extensive potential, the metabolic profiles among different rosehip species have not been fully elucidated. In this study, 523 secondary metabolites from rosehips of 12 Rosa species were identified using ultra-high-performance liquid chromatography-tandem mass spectrometry. They were primarily composed of flavonoids and phenolic acids. A K-means analysis revealed the characteristic metabolites in different rosehips. For example, R. persica contained a more abundant supply of phenolic acids, while R. roxburghii harbored a richer array of terpenoids. A total of 73 key active ingredients were screened from traditional Chinese medicine databases, and they indicated that R. persica is more promising for use in functional foods or health supplements compared with the other fruits. Moreover, a differential analysis identified 47 compounds as potential contributors to the astringent taste of rosehips, including ellagic acid 4-O-glucoside and cadaverine. This study provides valuable information to develop new functional foods of rosehips and improve the quality of their fruits.

The chromosome-level genome and functional database accelerate research about biosynthesis of secondary metabolites in Rosa roxburghii.

Rosa roxburghii Tratt, a valuable plant in China with long history, is famous for its fruit. It possesses various secondary metabolites, such as L-ascorbic acid (vitamin C), alkaloids and poly saccharides, which make it a high nutritional and medicinal value. Here we characterized the chromosome-level genome sequence of R. roxburghii, comprising seven pseudo-chromosomes with a total size of 531 Mb and a heterozygosity of 0.25%. We also annotated 45,226 coding gene loci after masking repeat elements. Orthologs for 90.1% of the Complete Single-Copy BUSCOs were found in the R. roxburghii annotation. By aligning with protein sequences from public platform, we annotated 85.89% genes from R. roxburghii. Comparative genomic analysis revealed that R. roxburghii diverged from Rosa chinensis approximately 5.58 to 13.17 million years ago, and no whole-genome duplication event occurred after the divergence from eudicots. To fully utilize this genomic resource, we constructed a genomic database RroFGD with various analysis tools. Otherwise, 69 enzyme genes involved in L-ascorbate biosynthesis were identified and a key enzyme in the biosynthesis of vitamin C, GDH (L-Gal-1-dehydrogenase), is used as an example to introduce the functions of the database. This genome and database will facilitate the future investigations into gene function and molecular breeding in R. roxburghii.

Combined Metabolite and Transcriptomic Profiling Unveil a Potential Gene Network Involved in the Triterpenoid Metabolism of Rose roxburghii.

Rose roxburghii, a horticulturally significant species within the Rosa genus of the Rosaceae family, is renowned for its abundance of secondary metabolites and ascorbate, earning it the title 'king of vitamin C'. Despite this recognition, the mechanisms underlying the biosynthesis and regulation of triterpenoid compounds in R. roxburghii remain largely unresolved. In this study, we conducted high-performance liquid chromatography profiling across various organs of R. roxburghii, including fruit, root, stem, and leaves, revealing distinct distributions of triterpenoid compounds among different plant parts. Notably, the fruit exhibited the highest total triterpenoid content, followed by root and stem, with leaf containing the lowest levels, with leaf containing the lowest levels. Transcriptomic analysis unveiled preferential expression of members from the cytochrome P450 (CYP) and glycosyltransferase (UGT) families, likely contributing to the higher accumulation of both ascorbate and triterpenoid compounds in the fruits of R. roxburghii compared to other tissues of R. roxburghii. Transcriptomic analysis unveiled a potential gene network implicated in the biosynthesis of both ascorbate and triterpenoid compounds in R. roxburghii. These findings not only deepen our understanding of the metabolic pathways in this species but also have implications for the design of functional foods enriched with ascorbate and triterpenoids in R. roxburghii.

Bioactive metabolite profiles and quality of Rosa rugosa during its growing and flower-drying process.

Rosa rugosa is extensively cultivated in China for its remarkable fragrance and flavor, however, the metabolic changes in roses during growth and drying remain unclear. Our results revealed significant variations in phenol and flavonoid contents and antioxidant capacity in roses (Rosa rugosa f. plena (Regel) Byhouwer) under different conditions. Phenol contents were positively correlated with antioxidant capacity, with phytochemicals being most prominent in unfolded petals. The highest antioxidant capacity and phenol and flavonoid contents were observed in April. Considering their greater consumption value, whole flowers were more suitable than petals alone. Furthermore, considerable sensory and nutritional differences were observed in dried roses. Different drying methods increased their total phenol content of roses by 4.2-5.4 times and the antioxidant capacity by 2.9 times. Metabolomics revealed the altered contents of flavonoids, anthocyanins, lipids, amino acids, and saccharides. This study provides baseline data for the potential of roses as a natural source of antioxidants in the food and pharmaceutical industries.

The transcription factor RhMYB17 regulates the homeotic transformation of floral organs in rose (Rosa hybrida) under cold stress.

Low temperatures affect flower development in rose (Rosa hybrida), increasing petaloid stamen number and reducing normal stamen number. We identified the low-temperature-responsive R2R3-MYB transcription factor RhMYB17, which is homologous to Arabidopsis MYB17 by similarity of protein sequences. RhMYB17 was up-regulated at low temperatures, and RhMYB17 transcripts accumulated in floral buds. Transient silencing of RhMYB17 by virus-induced gene silencing decreased petaloid stamen number and increased normal stamen number. According to the ABCDE model of floral organ identity, class A genes APETALA 1 (AP1) and AP2 contribute to sepal and petal formation. Transcription factor binding analysis identified RhMYB17 binding sites in the promoters of rose APETALA 2 (RhAP2) and APETALA 2-LIKE (RhAP2L). Yeast one-hybrid assays, dual-luciferase reporter assays, and electrophoretic mobility shift assays confirmed that RhMYB17 directly binds to the promoters of RhAP2 and RhAP2L, thereby activating their expression. RNA sequencing further demonstrated that RhMYB17 plays a pivotal role in regulating the expression of class A genes, and indirectly influences the expression of the class C gene. This study reveals a novel mechanism for the homeotic transformation of floral organs in response to low temperatures.

Telo boxes within the AGAMOUS second intron recruit histone 3 lysine 27 methylation to increase petal number in rose (Rosa chinensis) in response to low temperatures.

The petals of rose (Rosa sp.) flowers determine the ornamental and industrial worth of this species. The number of petals in roses was previously shown to be subject to fluctuations in ambient temperature. However, the mechanisms by which rose detects and responds to temperature changes are not entirely understood. In this study, we identified short interstitial telomere motifs (telo boxes) in the second intron of AGAMOUS (RcAG) from China rose (Rosa chinensis) that play an essential role in precise temperature perception. The second intron of RcAG harbors two telo boxes that recruit telomere repeat binding factors (RcTRBs), which interact with CURLY LEAF (RcCLF) to compose a repressor complex. We show that this complex suppresses RcAG expression when plants are subjected to low temperatures via depositing H3K27me3 marks (trimethylation of lysine 27 on histone H3) over the RcAG gene body. This regulatory mechanism explains the low-temperature-dependent decrease in RcAG transcript levels, leading to the production of more petals under these conditions. Our results underscore an interesting intron-mediated regulatory mechanism governing RcAG expression, enabling rose plants to perceive temperature cues and establish petal numbers.

The Antiobesity Effects of Rosehip (Rosa canina) Flesh by Antagonizing the PPAR Gamma Activity in High-Fat Diet-Fed Mice.

SCOPE: The rosehip (Rosa canina) is a perennial shrub with a reddish pseudofruit that has demonstrated antidiabetic, antiatherosclerotic, and antiobesogenic effects in rodent models but there is low information about the molecular mechanisms underlying these effects on the onset and progression of diet-induced obesity. METHODS AND RESULTS: Four-week-old C57BL/6J male mice are subjected to a high-fat diet (HFD)-supplemented or not with R. canina flesh for 18 weeks. The results indicated that the R. canina flesh exerts a preventive effect on HFD-induced obesity with a significant reduction in body-weight gain and an improvement of hyperglycemia and insulin resistance caused by a HFD. At the tissue level, subcutaneous white adipose tissue exhibits a higher number of smaller adipocytes, with decreased lipogenesis. On its side, the liver shows a significant decrease in lipid droplet content and in the expression of genes related to lipogenesis, fatty acid oxidation, and glucose metabolism. Finally, the data suggest that most of these effects agree with the presence of a putative Perosxisome proliferator-activated receptor gamma (PPARγ) antagonist in the R. canina flesh. CONCLUSIONS: R. canina flesh dietary supplementation slows down the steatotic effect of a HFD at least in part through the regulation of the transcriptional activity of PPARγ.

The F-box protein RhSAF destabilizes the gibberellic acid receptor RhGID1 to mediate ethylene-induced petal senescence in rose.

Roses are among the most popular ornamental plants cultivated worldwide for their great economic, symbolic, and cultural importance. Nevertheless, rapid petal senescence markedly reduces rose (Rosa hybrida) flower quality and value. Petal senescence is a developmental process tightly regulated by various phytohormones. Ethylene accelerates petal senescence, while gibberellic acid (GA) delays this process. However, the molecular mechanisms underlying the crosstalk between these phytohormones in the regulation of petal senescence remain largely unclear. Here, we identified SENESCENCE-ASSOCIATED F-BOX (RhSAF), an ethylene-induced F-box protein gene encoding a recognition subunit of the SCF-type E3 ligase. We demonstrated that RhSAF promotes degradation of the GA receptor GIBBERELLIN INSENSITIVE DWARF1 (RhGID1) to accelerate petal senescence. Silencing RhSAF expression delays petal senescence, while suppressing RhGID1 expression accelerates petal senescence. RhSAF physically interacts with RhGID1s and targets them for ubiquitin/26S proteasome-mediated degradation. Accordingly, ethylene-induced RhGID1C degradation and RhDELLA3 accumulation are compromised in RhSAF-RNAi lines. Our results demonstrate that ethylene antagonizes GA activity through RhGID1 degradation mediated by the E3 ligase RhSAF. These findings enhance our understanding of the phytohormone crosstalk regulating petal senescence and provide insights for improving flower longevity.

Chromosomal-scale genomes of two Rosa species provide insights into genome evolution and ascorbate accumulation.

Rosa roxburghii and Rosa sterilis, two species belonging to the Rosaceae family, are widespread in the southwest of China. These species have gained recognition for their remarkable abundance of ascorbate in their fresh fruits, making them an ideal vitamin C resource. In this study, we generated two high-quality chromosome-scale genome assemblies for R. roxburghii and R. sterilis, with genome sizes of 504 and 981.2 Mb, respectively. Notably, we present a haplotype-resolved, chromosome-scale assembly for diploid R. sterilis. Our results indicated that R. sterilis originated from the hybridization of R. roxburghii and R. longicuspis. Genome analysis revealed the absence of recent whole-genome duplications in both species and identified a series of duplicated genes that possibly contributing to the accumulation of flavonoids. We identified two genes in the ascorbate synthesis pathway, GGP and GalLDH, that show signs of positive selection, along with high expression levels of GDP-d-mannose 3', 5'-epimerase (GME) and GDP-l-galactose phosphorylase (GGP) during fruit development. Furthermore, through co-expression network analysis, we identified key hub genes (MYB5 and bZIP) that likely regulate genes in the ascorbate synthesis pathway, promoting ascorbate biosynthesis. Additionally, we observed the expansion of terpene synthase genes in these two species and tissue expression patterns, suggesting their involvement in terpenoid biosynthesis. Our research provides valuable insights into genome evolution and the molecular basis of the high concentration of ascorbate in these two Rosa species.

Nano-silicone and Ascophyllum nodosum-based biostimulant down-regulates the negative effect of in vitro induced-salinity in Rosa damascena.

BACKGROUND: Rosa damascena is extensively cultivated in various regions of Iran due to its aesthetic attributes, medicinal qualities, and essential oil production. This study investigated the efficacy of Ascophyllum nodosum extract (AnE) at concentrations of 0, 2, and 3 g L- 1 and Nano-silicon (nSiO2) at concentrations of 0, 50, and 100 mg L- 1 in ameliorating the impact of salinity on two genotypes of Damask rose ('Chaharfasl' and 'Kashan') under in vitro culture conditions. Additionally, various physio-chemical characteristics of R. damascena explants were assessed. RESULTS: The findings revealed that exposure to 100 mM NaCl resulted in a substantial reduction in the Relative Water Content (RWC), Membrane Stability Index (MSI), leaf pigments (Chlorophyll b, Chlorophyll a, total Chlorophyll, and carotenoids), chlorophyll fluorescence parameters, and protein content in both genotypes when compared to control conditions. Salinity induced a significant increase in the parameter F0 and a decrease in the parameter Fv/Fm compared to the control conditions in both genotypes. Nonetheless, the genotype Kashan treated with 3 g L- 1 AnE + 100 mg L- 1 nSiO2 exhibited the maximum Fm value under control conditions, with a significant difference compared to other treatments. Furthermore, salinity caused a considerable reduction in Fm in both 'Kashan' and 'Chaharfasl' by 22% and 17%, respectively, when compared to the control condition. 'Kashan' displayed the maximum Fv/Fm compared to the other genotype. The maximum levels of Malondialdehyde (MAD) and hydrogen peroxide (H2O2) were also observed in explants affected by salinity. The combination of 3 g L- 1 AnE + 100 mg L- 1 nSiO2, followed by 2 g L- 1 AnE + 100 mg L- 1 nSiO2, exhibited substantial positive effects. Salinity also led to an increase in proline content and the activity of peroxidase (POD), superoxide dismutase (SOD), guaiacol peroxidase (GPX), and catalase (CAT) in both genotypes. The activity of these enzymes was further enhanced when AnE was applied at concentrations of 2 and 3 g L- 1 in combination with 100 mg L- 1 nSiO2. CONCLUSIONS: The 'Kashan' genotype displayed greater tolerance to salinity by enhancing water balance, maintaining membrane integrity, and augmenting the activity of antioxidant enzymes compared to 'Chaharfasl'. The utilization of nSiO2 and AnE biostimulants demonstrated potential benefits for R. damascena, both under salinity and control conditions. These findings hold substantial importance for researchers, policymakers, and farmers, offering valuable insights into the development of salinity-tolerant crop varieties.

Ethanol Extract of Rosa rugosa Ameliorates Acetaminophen-Induced Liver Injury via Upregulating Sirt1 and Subsequent Potentiation of LKB1/AMPK/Nrf2 Cascade in Hepatocytes.

Acetaminophen (APAP)-induced liver injury is a common hepatic disease resulting from drug abuse. Few targeted treatments are available clinically nowadays. The flower bud of Rosa rugosa has a wide range of biological activities. However, it is unclear whether it alleviates liver injury caused by APAP. Here, we prepared an ethanol extract of Rosa rugosa (ERS) and analyzed its chemical profile. Furthermore, we revealed that ERS significantly ameliorated APAP-induced apoptosis and ferroptosis in AML-12 hepatocytes and dampened APAP-mediated cytotoxicity. In AML-12 cells, ERS elevated Sirt1 expression, boosted the LKB1/AMPK/Nrf2 axis, and thereby crippled APAP-induced intracellular oxidative stress. Both EX527 and NAM, which are chemically unrelated inhibitors of Sirt1, blocked ERS-induced activation of LKB1/AMPK/Nrf2 signaling. The protection of ERS against APAP-triggered toxicity in AML-12 cells was subsequently abolished. As expression of LKB1 was knocked down, ERS still upregulated Sirt1 but failed to activate AMPK/Nrf2 cascade or suppress cytotoxicity provoked by APAP. Results of in vivo experiments showed that ERS attenuated APAP-caused hepatocyte apoptosis and ferroptosis and improved liver injury and inflammation. Consistently, ERS boosted Sirt1 expression, increased phosphorylations of LKB1 and AMPK, and promoted Nrf2 nuclear translocation in the livers of APAP-intoxicated mice. Hepatic transcriptions of HO-1 and GCLC, which are downstream antioxidant genes of Nrf2, were also significantly increased in response to ERS. Our results collectively indicated that ERS effectively attenuates APAP-induced liver injury by activating LKB1/AMPK/Nrf2 cascade. Upregulated expression of Sirt1 plays a crucial role in ERS-mediated activation of LKB1.

The Basic/Helix-Loop-Helix Transcription Factor Family Gene RcbHLH112 Is a Susceptibility Gene in Gray Mould Resistance of Rose (Rosa Chinensis).

The basic/helix-loop-helix (bHLH) family is a major family of transcription factors in plants. Although it has been reported that bHLH plays a defensive role against pathogen infection in plants, there is no comprehensive study on the bHLH-related defence response in rose (Rosa sp.). In this study, a genome-wide analysis of bHLH family genes (RcbHLHs) in rose was carried out, including their phylogenetic relationships, gene structure, chromosome localization and collinearity analysis. Via phylogenetic analysis, a total of 121 RcbHLH genes in the rose genome were divided into 21 sub-groups. These RcbHLHs are unevenly distributed in all 7 chromosomes of rose. The occurrence of gene duplication events indicates that whole-genome duplication and segmental duplication may play a key role in gene duplication. Ratios of non-synonymous to synonymous mutation frequency (Ka/Ks) analysis showed that the replicated RcbHLH genes mainly underwent purification selection, and their functional differentiation was limited. Gene expression analysis showed that 46 RcbHLHs were differentially expressed in rose petals upon B. cinerea infection. It is speculated that these RcbHLHs are candidate genes that regulate the response of rose plants to B. cinerea infection. Virus-induced gene silencing (VIGS) confirmed that RcbHLH112 in rose is a susceptibility factor for infection with B. cinerea. This study provides useful information for further study of the functions of the rose bHLH gene family.

In vitro assessment of physiological traits and ROS detoxification pathways involved in tolerance of Damask rose genotypes under salt stress.

Rosa damascena is one of the most important medicinal and ornamental plants in Iran which is tolerant of salinity to some extent. However, the selection of genotypes that are more tolerant to salinity will influence on Damask cultivation in salt stress-affected regions. For this purpose, a factorial experiment in a completely randomized design with three replicates was performed under in vitro conditions on four Damask rose genotypes (Atashi, Bi-Khar, Chahar-Fasl and Kashan) at 5 concentrations of NaCl (0, 25, 50, 75, and 100 mM), and the physico-chemical traits were measured 14 and 28 days after treatment.The results showed that Atashi genotype with high levels of Chl a, Chl b, total Chl content, carotenoids, relative leaf water content, proline, total soluble protein, TPC, TFC, TAA, and the highest increase in the activity of antioxidant enzymes such as GPX, APX, CAT, SOD, and POD as well as the lowest amount of hydrogen peroxide showed a better protection mechanism against oxidative damage than the other three genotypes (Bi-Khar, Chahar-Fasl and Kashan) in the 14th and 28th days by maintaining the constructive and induced activities of antioxidant enzymes, it was shown that Bi-Khar genotype had moderate tolerance and Kashan and Chahar-Fasl genotypes had low tolerance to salinity stress. In vitro selection methods can be used effectively for salt tolerant screening of Damask rose genotypes, although the same experiment should be conducted in open filed cultures to verify the in vitro experimental results.

Rosa laevigata Michx. Polysaccharide Ameliorates Diabetic Nephropathy in Mice through Inhibiting Ferroptosis and PI3K/AKT Pathway-Mediated Apoptosis and Modulating Tryptophan Metabolism.

Diabetic nephropathy (DN) is a metabolic disease wherein chronic hyperglycemia triggers various renal cell dysfunctions, eventually leading to progressive kidney failure. Rosa laevigata Michx. is a traditional Chinese herbal medicine. Many studies have confirmed its antioxidative, anti-inflammatory, and renoprotective effects. However, the effects and mechanisms of Rosa laevigata Michx. polysaccharide (RLP) in DN remain unclear. In this study, a DN mouse model was established to investigate the therapeutic effect of RLP on DN mice. Then, nontargeted metabolomics was used to analyze the potential mechanism of RLP in the treatment of DN. Finally, the effects of RLP on ferroptosis and the PI3K/AKT pathway were investigated. The results demonstrated that RLP effectively alleviated renal injury and reduced inflammation and oxidative stress in the kidney. In addition, nontargeted metabolomic analysis indicated that RLP could modulate riboflavin metabolism and tryptophan metabolism in DN mice. Notably, ferroptosis and PI3K/AKT pathway-mediated apoptosis in the kidney were also ameliorated following RLP treatment. In conclusion, this study confirmed that RLP had a significant therapeutic effect on DN mice. Furthermore, RLP treatment modulated tryptophan metabolism and inhibited ferroptosis and PI3K/AKT pathway-mediated apoptosis in the kidney.

Evaluation of the flavonol-rich fraction of Rosa damascena in an animal model of liver fibrosis by targeting the expression of fibrotic cytokines, antioxidant/oxidant ratio and collagen cross-linking.

INTRODUCTION: The flavonoid-rich fraction of Rosa damascena (FRFRD) contains antioxidant and active compounds. Therefore, this study aimed to investigate the role of FRFRD, rich in quercetin and kaempferol, in liver fibrosis induced by CCl4. MATERIALS AND METHODS: The FRFRD fraction was separated and standardized by High-Performance Liquid Chromatography (HPLC) based on the levels of quercetin and kaempferol. Liver fibrosis was induced over CCl4 over 12 weeks in 30 male Wistar rats, and three concentrations of FRFRD were administered to them during the last four weeks. Subsequently, after evaluation of liver serum markers and fibrotic parameters, the relative expression of transforming growth factor-beta-1 (TGF-ß1), platelet-derived growth factor (PDGF), and lysyl oxidase homolog 2 (Loxl2) genes were assessed, along with the measurement of lysyl oxidase activity and oxidative markers. RESULTS: Fibrotic markers demonstrated progressive recovery of liver damage in the treated group compared to the non-treatment group (p < 0.01). These results were accompanied by a significant decrease in the expression of TGF-ß1, PDGF, and Loxl2 genes, as well as, a reduction in lysyl oxidase activity (p < 0.001). The antioxidant effects of the treatment were observed through a significant decrease in malondialdehyde (MDA) levels and an increase in catalase enzyme (CAT) and glutathione peroxidase (GPx) activity in the treatment group compared to the fibrotic group (p < 0.01). CONCLUSION: The flavonoid-rich fraction of Rosa damascena ameliorates liver damage by affecting collagen cross-linking and lowering oxidative and inflammatory levels.

CuZn-superoxide dismutase is differentially modified in localization and expression by three abiotic stresses in miniature rose bushes.

Three abiotic stresses, copper application (CS), mechanical rubbing (MS) and water deprivation (WS) applied on miniature rose bushes specifically activate the expression of the CuZn-Superoxide dismutase (SOD). The Cu/Zn-SOD protein immunodetected in the 4th internode was shown engaged in lignification in phloem, cambium and xylem cells. The SOD occurrence was detailed in the vessel associated cells (VACs), using immunogold labeling observed in transmission electron microscopy. The enzyme was detected in mitochondria, plastids, Golgi vesicles, endoplasmic reticulum and plasma membrane. In addition, in pit-fields without plasmodesmata linking vessel associated cells to vessels, the abiotic stresses increased the transfer apparatus volume. The content in unmethylatedpectins increased in wall ingrowths after CS and MS, but not in WS. In addition to the different localization, the SOD was differentially overexpressed according to the applied stress: an isoform detected at 17 kDa under CuSO4 application, two isoforms respectively detected at 20 and 17 kDa under MS and detected at 17 and 15 kDa under WS. Notably, the only 17 kDa isoform was detected in plasma membrane vesicles from plants submitted to the three stresses. Thus, by increasing the transfer apparatus development, the key role of VACs was emphasized in establishing an adaptative response to abiotic stresses, in miniature rose bushes. Additionally, it has been observed that the differential SOD localization under such stresses sustained the regulatory function of VACs in the transitory sink function of xylem.

Hibiscus rosa-sinensis as a potential hyperaccumulator in metal contaminated magnesite mine tailings.

Mining is one of the major contributors for land degradation and severe heavy metals based soil pollution. In this study, the physicochemical properties of magnesite mine soil was investigated and assess the optimistic and eco-friendly remediation approach with Hibiscus rosa-sinensis with the effect of pre-isolated Acidithiobacillus thiooxidans. The physicochemical properties analysis results revealed that most the parameter were either too less or beyond the permissible limits. The pre-isolated A. thiooxidans showed remarkable multi-metal tolerance up to 800 µg mL-1 concentration of Cr, Cd, Pb, and Mn. Heavy metal content in polluted soil was reduced to avoid more metal toxicity by diluting with fertile control soil as 80:20 and 60:40. The standard greenhouse experiment was performed to evaluate the phytoextraction potential of H. rosa-sinensis under the influence of A. thiooxidans in various treatment groups (G-I to G-V). The outcome of this investigation was declared that the multi-metal tolerant A. thiooxidans from G-III and G-II showed remarkable effect on growth and phytoextraction ability of H. rosa-sinensis on metal polluted magnesite mine soil in 180 d greenhouse study. These results suggested that the combination of H. rosa-sinensis and A. thiooxidans could be used as an excellent hyper-accumulator to extract metal pollution from polluted soil.

Mechanistic Insights into Roseoflavin Synthesis by N,N-8-Demethyl-8-aminoriboflavin Dimethyltransferase (RosA): Molecular Dynamics Simulations and Residue Conservation Analysis.

8-Demethyl-8-dimethylaminoriboflavin (Roseoflavin or RoF) is a natural riboflavin analogue found in Streptomyces davaonensis and Streptomyces cinnabarinus. RoF displays potent antibiotic properties because it affects FMN riboswitches and flavoproteins of cellular targets. N,N-8-Demethyl-8-aminoriboflavin dimethyltransferase (RosA) is an enzyme that catalyzes the last step of RoF biosynthesis, a consecutive dimethylation of 8-demethyl-8-aminoriboflavin (AF) to generate RoF. Thus, understanding mechanistic insights into RosA structures and mechanisms could lead to the improvement of the RoF product yield. Herein, mechanistic insights into roseoflavin synthesis by RosA were evaluated using molecular dynamics simulations. The obtained results revealed that RosA possibly catalyzes the reaction by positioning the substrate binding to have proper distance and orientation to the methyl group donor, S-adenosylmethionine. No direct participation of catalytic residues in the reaction was identified. The enzyme's active site structures change drastically to accommodate the ligand binding. On the basis of the MM/GBSA calculations and conservation analysis, the amino acid residues involved in substrate binding were identified. The structural information obtained from this study could be beneficial in designing RosA to efficiently produce roseoflavin.