Optimizing the extract yield of bioactive compounds in Valeriana officinalis root: a D-optimal design.

It is estimated that 80% of all synthetic drugs are derived from medicinal plants, and nowadays, many synthetic drugs are derived from medicinal plants. Valeriana officinalis can treat many diseases of the nervous system. A crucial aspect of valerian extract is that it inhibits the proliferation of breast cancer cells. To optimize the yield of bioactive compounds in the V. officinalis root extraction, a response surface methodology-based D-optimal design was used. To fulfill this aim, the effects of various factors such as solvent type and concentration, mixing temperature, ultrasound time, and drying method were examined. The optimal conditions for solvent percentages, mixing temperature, ultrasound time, solvent type, and drying methods were determined to be 94.88%, 25 °C, 48.95 min, methanol, and microwave, respectively, with a desirability of 0.921. The predicted valerenic acid, total phenols, total flavonoids, and antioxidant activity in V. officinalis extract were 1.19 (mg/g DW), 8.22 (mg/g DW), 5.27 (mg/g DW), and 92.64%, respectively. In optimal conditions, the extracted amounts of valerenic acid, total phenols, total flavonoids, and antioxidant activity were 2.07 mg/g DW, 7.96 mg/g DW, 5.52 mg/g DW, and 78.68%, respectively, which were consistent with the model predicted amounts (based on 95% prediction interval). This study could be useful as a model for demonstrating the efficacy of microwave drying to maximize the biochemical content of V. officinalis, as well as the antioxidant activity of the root extracts of V. officinalis on industrial scale.

Thymol antifungal mode of action involves telomerase inhibition.

The antifungal mode of action of thymol was investigated by a chemical-genetic profile analysis. Growth of each of ~4700 haploid Saccharomyces cerevisiae gene deletion mutants was monitored on medium with a subinhibitory concentration (50 µg/ml) of thymol and compared to growth on non-thymol control medium. This analysis revealed that, of the 76 deletion mutants with the greatest degree of susceptibility to thymol, 29% had deletions in genes involved in telomere length maintenance. A telomere restriction fragment (TRF) length assay showed that yeast exposed to a subinhibitory concentration of thymol for 15 days had telomere size reductions of 13-20% compared to non-thymol controls. By accelerating telomere shortening, thymol may increase the rate of cell senescence and apoptosis. Furthermore, real-time RT-PCR analysis revealed approximately two-fold reductions in EST2 mRNA but no change in TLC1 RNA in thymol-treated S. cerevisiae relative to untreated cells. EST2 encodes the essential reverse transcriptase subunit of telomerase that uses TLC1 RNA as a template during addition of TG(1-3) repeats to maintain telomere ends. This study provides compelling evidence that a primary mode of thymol antifungal activity is through inhibition of transcription of EST2 and thus telomerase activity.

Stimulation of Secondary Metabolites and γ-Terpinene Synthase by Silver Nanoparticles in Callus Cultures of Carum carvi.

Biotechnology and nanotechnology are important tools for understanding biochemical pathways. They can be used efficiently for stimulating and increasing the production of secondary metabolites in medicinal plants. The present study aimed to identify the γ-terpinene synthase gene (CcTPS2) as an effective contributor to the biosynthetic pathway of monoterpenes. The effects of silver nanoparticles (AgNPs; 50 and 100 mg l- 1) and time (24 and 48 h) were examined on secondary metabolites in cell suspension cultures of Carum carvi. This involved the identification, isolation, and sequencing of a partial sequence in the CcTPS2 gene of C. carvi. The genomic sequence of CcTPS2 comprised 292 bp which were organized into two exons (110 and 82 bp) and one intron (100 bp), while the cDNA was 192 bp. In the scale of nucleotides, the CcTPS2 gene showed 96% similarity with the TPS2 gene of Oliveria decumbens. We generated sequence data of the CcTPS2 gene for the first time in this species, thereby enabling further developments in understanding the molecular mechanisms responsible for terpene biosynthesis and other chemical derivatives in C. carvi. The results of GC/MS and GC/FID showed that AgNPs strongly affected the secondary metabolites in cell suspension cultures of C. carvi. According to the results, the AgNPs (50 mg l- 1) increased p-cymene and carvone contents in comparison with the control. The exposure of plants to 100 mg l- 1 AgNPs induced the production of thymol and carvacrol. The results of real-time PCR revealed that the exposure of plants to 100 mg l- 1 AgNPs caused a significant upregulation of CcTPS2 expression for 24 h. These cell suspension cultures were elicited by AgNPs, the application of which proved as an effective method to improve the production of secondary metabolites in vitro.

Stipagrostis pennata (Trin.) De Winter Artificial Seed Production and Seedlings Multiplication in Temporary Immersion Bioreactors

This study was conducted to develop the protocol for artificial seed production of Stipagrostis pennata (Trin.) De Winter via somatic embryo encapsulation as well as test a temporary bioreactor system for germination and seedling growth. Embryogenic calli were encapsulated using sodium alginate and calcium chloride and then sowed in the Murashige and Skoog (MS) germination medium in in vitro cultures. The experiments were conducted as a factorial based on a completely randomized design with three replications. The treatments include three concentrations of sodium alginate (1.5%, 2.5%, and 3.5%), two ion exchange times (20 and 30 min), and two artificial seed germination media (hormone-free MS and MS supplemented with zeatin riboside and L-proline). Germination percentage and number of days needed until the beginning of germination were studied. The highest percentage of artificial seed germination was obtained when 2.5% sodium alginate was used for 30 min (ion exchange time) and when the seeds were placed on the MS germination medium supplemented with zeatin riboside and L-proline. The results of the analysis of variance in the temporary immersion bioreactor system showed that the main effects observed on the seedling growth were associated with different growth hormones in culture media and the number of feeding cycles. Experimental results also indicated that the total protein analyses of zygotic seedlings and seedlings originating from the synthetic seeds showed no statistically significant differences between these samples.

Molecular and Physiological Variability in Bread Wheat and Its Wild Relative (Aegilops tauschii Coss.) Species under Water-Deficit Stress Conditions.

Aegilops and Triticum spp. are two ideal gene pools for the breeding purposes of wheat. In this study, a set of Iranian accessions of Aegilops tauschii Coss. and Triticum aestivum L. species were evaluated in terms of some physiological and biochemical features under control and water-deficit stress conditions. Moreover, several simple sequence repeat (SSR) markers were employed to identify marker loci associated with the measured traits. The results indicated that water-deficit stress significantly affected all measured traits and the highest reductions due to water-deficit were recorded for shoot fresh and dry biomasses (SFB and SDB), stomatal conductance (Gs), leaf relative water content (RWC), and chlorophyll b content (Chl b). In molecular analysis, 25 SSR markers generated 50 fragments, out of which 49 fragments (98%) were polymorphic. Furthermore, the genetic variation observed within species is more than between species. The results of cluster and Bayesian model analysis classified all evaluated accessions into three main clusters. Under control and water-deficit stress conditions, 28 and 27 significant marker-trait associations (MTAs) were identified, respectively. Furthermore, 10 MTAs showed sufficiently stable expression across both growth conditions. Of these, the markers Xgwm-111, Xgwm-44, Xgwm-455, Xgwm-272, and Xgwm-292 were associated with multiple traits. Hence, these markers could serve as useful molecular tools for population characterization, gene tagging, and other molecular breeding studies.

Protocol development for somatic embryogenesis, SSR markers and genetic modification of Stipagrostis pennata (Trin.) De Winter.

BACKGROUND: Stipagrostis pennata (Trin.) De Winter is an important species for fixing sand in shifting and semi-fixed sandy lands, for grazing, and potentially as a source of lignocellulose fibres for pulp and paper industry. The seeds have low viability, which limits uses for revegetation. Somatic embryogenesis offers an alternative method for obtaining large numbers of plants from limited seed sources. RESULTS: A protocol for plant regeneration from somatic embryos of S. pennata was developed. Somatic embryogenesis was induced on Murashige & Skoog (MS) medium supplemented with 3 mg·L-1 2,4-D subsequently shoots were induced on MS medium and supplemented with 5 mg·L-1 zeatin riboside. The highest shoots induction was obtained when embryogenic callus derived from mature embryos (96%) in combination with MS filter-sterilized medium was used from Khuzestan location. The genetic stability of regenerated plants was analysed using ten simple sequence repeats (SSR) markers from S. pennata which showed no somaclonal variation in regenerated plants from somatic embryos of S. pennata. The regenerated plants of S. pennata showed genetic stability without any somaclonal variation for the four pairs of primers that gave the expected amplicon sizes. This data seems very reliable as three of the PCR products belonged to the coding region of the genome. Furthermore, stable expression of GUS was obtained after Agrobacterium-mediated transformation using a super binary vector carried by a bacterial strain LBA4404. CONCLUSION: To our knowledge, the current work is the first attempt to develop an in vitro protocol for somatic embryogenesis including the SSR marker analyses of regenerated plants, and Agrobacterium-mediated transformation of S. pennata that can be used for its large-scale production for commercial purposes.

A comparative proteome approach to decipher the mechanism of rice adaptation to phosphorous deficiency.

Mineral deficiency limits crop production in most soils and in Asia alone, about 50% of rice lands are phosphorous deficient. In an attempt to determine the mechanism of rice adaptation to phosphorous deficiency, changes in proteome patterns associated with phosphorous deficiency have been investigated. We analyzed the parental line Nipponbare in comparison to its near isogenic line (NIL6-4) carrying a major phosphorous uptake QTL (Pup1) on chromosome 12. Using 2-DE, the proteome pattern of roots grown under 1 and 100 microM phosphorous were compared. Out of 669 proteins reproducibly detected on root 2-DE gels, 32 proteins showed significant changes in the two genotypes. Of them, 17 proteins showed different responses in two genotypes under stress condition. MS resulted in identification of 26 proteins involved in major phosphorous deficiency adaptation pathways including reactive oxygen scavenging, citric acid cycle, signal transduction, and plant defense responses as well as proteins with unknown function. Our results highlighted a coordinated response in NIL in response to phosphorous deficiency which may confer higher adaptation to nutrient deficiency.

Effect of ultrasonic waves on crocin and safranal content and expression of their controlling genes in suspension culture of saffron (Crocus sativus L.).

The expression of biosynthesis controlling genes of crocin and safranal in saffron (Crocus sativus) can be influenced by ultrasonic waves. Sterilized saffron corms were cultured in a ½-MS medium supplemented by 2-4-D and BAP.  Saffron callus cells were treated with ultrasonic waves in a cellular suspension culture under optimal growth conditions. The samples were collected at 24 and 72 hours after treatment in three replications. The secondary metabolites were measured by high-performance liquid chromatography and the gene expression was analysed by the real-time polymerase chain reaction. Results indicate that this elicitor can influence the expressions of genes CsBCH, CsLYC and CsGT-2; the ultrasonic waves acted as an effective mechanical stimulus to the suspension cultures. The analysis of variance of the ultrasonically produced amounts of safranal and crocin indicates that there is a significant difference between once- and twice-treated samples in that the amount of safranal was the highest within the samples taken from the twice-treated suspension culture at 72 h after the ultrasound treatment, and the crocin was maximised after 24 h passed the twice-applied ultrasound treatment.

Comparative analysis of the root and leaf transcriptomes in Chelidonium majus L.

Chelidonium majus is a traditional medicinal plant, which commonly known as a rich resource for the major benzylisoquinoline alkaloids (BIAs), including morphine, sanguinarine, and berberine. To understand the biosynthesis of C. majus BIAs, we performed de novo transcriptome sequencing of its leaf and root tissues using Illumina technology. Following comprehensive evaluation of de novo transcriptome assemblies produced with five programs including Trinity, Bridger, BinPacker, IDBA-tran, and Velvet/Oases using a series of k-mer sizes (from 25 to 91), BinPacker was found to produce the best assembly using a k-mer of 25. This study reports the results of differential gene expression (DGE), functional annotation, gene ontology (GO) analysis, classification of transcription factor (TF)s, and SSR and miRNA discovery. Our DGE analysis identified 6,028 transcripts that were up-regulated in the leaf, and 4,722 transcripts that were up-regulated in the root. Further investigations showed that most of the genes involved in the BIA biosynthetic pathway are significantly expressed in the root compared to the leaf. GO analysis showed that the predominant GO domain is "cellular component", while TF analysis found bHLH to be the most highly represented TF family. Our study further identified 10 SSRs, out of a total of 39,841, that showed linkage to five unigenes encoding enzymes in the BIA pathway, and 10 conserved miRNAs that were previously not detected in this plant. The comprehensive transcriptome information presented herein provides a foundation for further explorations on study of the molecular mechanisms of BIA synthesis in C. majus.

The antifungal eugenol perturbs dual aromatic and branched-chain amino acid permeases in the cytoplasmic membrane of yeast.

Eugenol is an aromatic component of clove oil that has therapeutic potential as an antifungal drug, although its mode of action and precise cellular target(s) remain ambiguous. To address this knowledge gap, a chemical-genetic profile analysis of eugenol was done using ∼4700 haploid Saccharomyces cerevisiae gene deletion mutants to reveal 21 deletion mutants with the greatest degree of susceptibility. Cellular roles of deleted genes in the most susceptible mutants indicate that the main targets for eugenol include pathways involved in biosynthesis and transport of aromatic and branched-chain amino acids. Follow-up analyses showed inhibitory effects of eugenol on amino acid permeases in the yeast cytoplasmic membrane. Furthermore, phenotypic suppression analysis revealed that eugenol interferes with two permeases, Tat1p and Gap1p, which are both involved in dual transport of aromatic and branched-chain amino acids through the yeast cytoplasmic membrane. Perturbation of cytoplasmic permeases represents a novel antifungal target and may explain previous observations that exposure to eugenol results in leakage of cell contents. Eugenol exposure may also contribute to amino acid starvation and thus holds promise as an anticancer therapeutic drug. Finally, this study provides further evidence of the usefulness of the yeast Gene Deletion Array approach in uncovering the mode of action of natural health products.

In vitro influences of TiO2 nanoparticles on barley (Hordeum vulgare L.) tissue culture.

In the last decades, extensive research on the effects of nano-TiO2 on plant systems and different microorganisms has confirmed its photocatalytic and antimicrobial activity. However, there is no report on its application in plant cell and tissue culture as well as its role in eliminating contaminating microorganisms in tissue culture. In this work, barley mature embryos were cultured in Murashige and Skoog medium with four concentrations (0, 10, 30, 60 µg/ml) of TiO2 suspension in four repetitions. Quantitative and qualitative characteristics of calli were analyzed after each subculture. Data analysis for calli number in the first culture and callus size in all three cultures showed that the effect of treatment was significant at p > 0.95. As a result, quantitative features such as callus color, shape, embryogenesis, etc. were completely similar in both control and TiO2 nanoparticle treatments; there is no doubt that TiO2 nanoparticles could dramatically increase callugenesis and the size of calli. As well, TiO2 nanoparticles are effective bactericides with an aseptic effect, causing no negative change in the quality of the callus. It is necessary to do more complementary works to identify mechanisms involved for the increased calli size and embryogenesis of explants in darkness.