جستجوی مقالات مرتبط با کلیدواژه « secondary metabolite » در نشریات گروه « بیوتکنولوژی و ژنتیک گیاهی »

Plants with special compounds in their root exudates can strengthen a specific microbial community in the rhizosphere and prevent harmful microbial community from forming. The rhizosphere is a dynamic region around the plant root that is governed by the interaction between the plant and microorganisms. Plant root secretions can be influenced by plant species, plant growth stages and stress conditions and can be different; therefore, each microbial strain can regulate the expression of its genes at each stage of plant growth. Microbes are an unknown and huge source of secondary metabolites that play a very important role in the field of medicine and other industries. The present review focuses on factors inducing the production of new secondary metabolites from rhizosphere microbes. Each microbial strain has the potential to produce several compounds, but considering that the production of secondary metabolites is very costly for the cell, their synthesis is highly controlled by the cell. Studies have shown that changing the growth conditions of microbes, such as: temperature, salinity, co-cultivation (bacteria-bacteria, fungi-fungi, bacteria-fungi), change in oxygen concentration, aeration speed, addition of soil elements and rare metal ions, light radiation and also genetic engineering methods such as: insertion of strong inducible promoters, ribosome engineering, chromatin rearrangement, overexpression of pathway-specific regulatory genes and small molecules and chemical stimuli can help to discover new compounds. In this study, the above cases are explained in detail.

Gall oak (Quercus infectoria) is one of the extraordinary tree species with functional medicinal properties within the oak family. Various studies have confirmed the presence of numerous secondary metabolites with therapeutic properties in this plant. Despite the significance of gall oak, its genetic structure remains elusive. Therefore, unraveling the genetic structure of gall ok may provide valuable insights into its potential applications across diverse industries. MicroRNAs emerge as pivotal genetic elements implicated in the biosynthesis of crucial metabolites across a wide range of different plant species. Despite the significant role of miRNAs in plants, as of yet, no miRNAs have been reported in Q. infectoria.. Therefore, in the present study, after assembling the transcriptome of Q. infectoria, the conserved microRNAs were identified.  Leaf and root samples of Q. infectoria were collected from trees in the Shineh region, and 2-year-old seedlings were grown from mature oaks in Khorramabad (Lorestan Province, Iran). Total RNA was extracted from roots and leaves using the Djami-Tchatchou method. After sequencing by the Illumina HiSeq 2500 platform and checking the quality of all the generated reads, the adapter sequences were removed, and the high-quality reads were assembled using Trinity package. To identify miRNAs and their target genes, all plant miRNAs sequences were downloaded from the miRbase database. The BLASTn algorithm was employed to identify the highest similarity between unigenes and mature plant miRNAs. Furthermore, BLASTx was used to search against the non-redundant proteins (NR) database to remove protein-coding unigenes. The investigation of miRNA second-structure prediction involved assessing the similarity between potential unigenes and mature miRNA sequences using the mfold web tool. Identification of miRNA target genes and gene ontology (GO) was performed using the psRNAtarget web-tool and OmicsBox software, respectively. Following a range of strict filtering criteria, four miRNAs belonging to conserved miRNAs families were identified, including qin-miR156, qin-miR399, qin-miR160, and qin-miR172. KEGG pathway analysis showed the target genes were involved in the citrate cycle pathway. Examining miRNA target genes in Q. infectoria and analyzing their interaction network, finally led to the identification of three hub genes. Identified miRNA target genes were associated with the biosynthesis of various enzyme groups, suggesting that most of miRNAs regulating hydrolases, transferases, and oxidoreductases. Given the role of microRNAs in regulating transcription factors and their impact on genes involved in secondary metabolite biosynthesis, future breeding programs in Q. infectoria may benefit from the potential of such regulatory elements as a guide and key.

Medicinal plants have long been recognized as a rich source of essential oils and have been cultivated for a variety of uses since ancient times. White savory (Satureja mutica fisch & CA mey) is one of the medicinal plants belonging to the mint family with high content of carvacrol in its essential oil. A large body of literature has suggested that abiotic stresses, especially drought stress, could considerably boost the production of essential oils in plants. The aim of this study was to evaluate the effect of drought stress on the expression of genes affecting the biosynthesis of the main component of white savory essential oil carvacrol.

For this goal, a number of 20 pot-planted seedlings of white savory at the 6-8 leaf stage were subjected in a greenhouse to two conditions of control and drought stress (10 pots for each condition) with irrigation regimes of 100% and 30% of field capacity, respectively. In order to ensure the implementation of stress on plants and to determine the appropriate time for sampling, leaf proline and relative water content of plants were measured.

The results of both proline and relative water content tests revealed a significant statistical difference between the control and stress conditions in white savory at 30% of field capacity. The KEGG (Kyoto Encyclopedia of Genes and Genomes) database was used to obtain information on carvacrol biosynthesis pathway. The three key genes geranyl diphosphate synthase (gpps), terpene synthase (tps), and limonene hydroxylase (lh) were chosen for gene expression analysis. Due to the lack of genomic information on white savory, the sequence information of the genes in the closest genera within the family mint was used to design primers. The result of melting curve analysis from the real-time quantitative PCR (qPCR) assay confirmed the accuracy of the primer design. The raw qPCR data normalized to the housekeeping gene Actin, then differential expression analysis was preformed using the delta delta Ct method. qPCR result showed that expression of the genes gpps, tps, and lh were increased in stressed plants proximately 20, 18, 50 times, compared to those in control, respectively. 

The conclusion that must be drawn from the data available is that water stress leads to the process of plant response to stress and changes the expression of genes involved in the biosynthesis pathway of the active substance carvacrol.

Silybum marianum L. from the Asteraceae is an annual or biennial plant widely distributed in the north, west and south of Iran. The fruits are containing medicinal flavonoids such as silymarin. This study was conducted to optimize the growing conditions for hairy roots and to assay the diverse factors affecting the induction and growth of hairy roots induced by Agrobacterium rhizogenes. The seeds were cultured on MS medium and were kept in the growth chamber. After germination and seedling growth; explants from the leaves, hypocotyl and roots were taken behind growth and after 5, 10 and 15 days. The explants were inoculated (treated) with two (R1000 and 15834) Agrobacterium rhizogenes strains. Furthermore, the effects of two inoculation methods (floating and injection) were assayed on the hairy roots emergence percentage. MS and 1/2 MS growing media were compared regarding the establishment of the hairy roots in the liquid medium. In a separate experiment, the effect of sucrose amount (20, 30 and 40 gl-1) were evaluated on hairy root induction and the roots emergence percentage was recorded. To verify the transgenic identity, PCR test with specific marker genes was carried out. The results revealed that 15834 strain was the strain of choice in 5 days old hypocotyl explants and produced more hairy roots than other strain. The best rooting percentage belonged to leaf explants at 15 days-old, treated with R1000. Floating was the method of choice for inoculation. 30 gL-1 sucrose was the best treatment for the root induction as well.

In this study for the first time, different strains of Agrobacterium rhizogenes, co-cultivation times, and concentrations of acetosyringon in leaf explants of Echium khuzistanicum were examined to produce hairy roots.

The leaves of 21-day-old plant, different concentrations of acetosyringone (0,100,200 µM) and 3 strains of Agrobacterium (A4, ATCC15834 and 11325) were used for hairy root induction. In each explant, surficial wounds were created by a syringe contaminated with the bacterium and put for 10 minutes in bacterial suspension. After infection, the explants were transferred in the ½ MS solid medium supplemented with ascorbic acid (100 mg/L) to a light free growth chamber with 25 ° C temperature for 48 or 72 hours. PCR technique was used to confirm transformation by gene amplification with the rolBprimers. HPLC analysis was conducted on a high performance liquid chromatography system for shikonin measurement.  

The results of this study showed that, the first hairy roots emerged from wounded places after 14-21 days. The presence of A. rhizogenes T-DNA in the hairy root genome was confirmed by PCR using specific primers for rolB gene. Strain ATCC15834 had the highest rate of hairy root induction at 100 and 200 µM concentrations of acetosyringone indicating that the phenolic compound, acetosyringone, was effective in increasing hairy root induction. Generally, High concentrations of acetosyringone and more co-cultivation time together resulted in a significant increase in the hairy root induction in three strains of Agrobacterium rhizogenesis. Line 1 of hairy root produced 254.4±0.56 µg/g FW of shikonin.  

For the first time the results of this research showed that transformation and hairy root induction in E.khuzistanicum is possible by Agrobacterium rhizogenes and it can be used in the gene transfer and hairy root culture in order to shikonin production.

Trigonella foenum-graecum is annual plant and dicotyldones of the fabaceae family. Root, leaf and seed have important medicinal compounds. Manipulation of cell culture media with elicitors is one of the important strategies for induction of secondary metabolism and production of valuable metabolites. Salicylic acid as a non-biological elicitor is effective in increasing the production of pharmaceutical metabolites. The aim of this study was to investigate the effect of salicylic acid on growth, some physiological and trigonelline production in in vitro culture of fenugreek. Fenugreek cell culture was obtained using cuticle extract of TN-47-155 fenugreek genotype in MS medium containing 0.35 mg / l TDZ and 0.05 mg / l IBA. Salicylic acid at concentrations of 12.5, 25, 50 mg / L were used. The cells were then treated with triglyceride and other physiological parameters after one week of treatment. The results of HPLC showed that cell growth and viability of the cells decreased as compared to the control. The amount of hydrogen peroxide and membrane lipid peroxidation in the cells increased compared to the control (without hormone) treatment. All treatments increased the production of TG and total phenol. Treatment of cells with 50 mg / l (75%) salicylic acid increased triglyceride levels twice as much as control (35%). Salicylic acid can be used as a stimulant in fenugreek cell culture and induces higher triglyceride production.

Black cumin (Nigella sativa) is an important medicinal plant belongs to the Ranunculaceae which produce large diversity of secondary metabolites including industrial and medicinal monoterpenes/ triterpenes. In the present work, relative gene expression of genes involved in biosynthetic pathway of terpenes including a monoterpene synthase (MTS), geranyldiphosphate synthase (GDS), β- amyrin synthase (βAS) and squaleneepoxidase(SQE) were investigated in black cumin plants treated with methyl jasmonate. The plants were grown in a greenhouse sprayed with 0.1 mM methyl jasmonate. Samples were collected at 0, 4, 8, 24, 48 and 72 hours after applying the treatments. RT-PCR was performed by gene-specific primers after RNA extraction and cDNA synthesis. Results of semi quantitative RT-PCR showed that the expression pattern of GDS gene differed with the results of other genes. The highest gene expression of GDS was observed at 4 h and its expression remained at the same level till 8 h then dropped at next time periods. The expression patterns of monoterpene synthase, β-amyrin synthase and squaleneepoxidase showed rising trend. Gene expression analysis of the genes at transcript level using semi-quantitative PCR in black cumin leaves treated by methyl jasmonate revealedinduced-geneexpression which might show the roles of terpenes in defense mechanisms and signal transduction. Consequently, methyl jasmonate treatment can be considered to induce the terpene biosynthetic pathway and to study the enzymes/ metabolites associated with terpenoid metabolism.

Cuminum cyminum is a drug plant of Apiaceae and is full of secondary metabolite such as flavonoids and anthocyanin compounds. Salicylic acid belongs to a group of phenolic compounds acts as a key secondary messenger in activating specific defensive response of plant and also is used as inducer in provement of biosynthesis of secondary metabolites. In this research the effect of salicylic acid on gene expression of flavone synthase and flavonoid and anthocyanins compounds was studied. In addition the effect of salicylic acid on malondialdehyde , hydrogen peroxide and antioxidant enzymes activity of catalase, peroxidase and superoxid dismutase are studied. Seedlings of cuminum cyminum in vegetative growth stage (21 days) were treated by 1.5 mM salicylic acid and was harvested on 1, 2, 3 and 4 days after treatment. The results showed that gene expression of flavone synthase, flavonoid and anthocyanin compounds in comparison with the control increased significantly. The most increase was observed in third day which were about twice more than control. But in fourth day was decreased but still was greater than control. In fact according to the research the positive correlation between gene expression of flavone synthase and flavonoids and anthosyanins compounds was observed. Comparing with control, the results showed that malondialdehyde, hydrogen peroxide and antioxidant enzymes activity are increasedin different harvest stages under treatment with salicylic acid. So salicylic acid as an inducer increased antioxidant system of plant and increased flavonoid and anthocyanin compounds of cuminum cyminum by increase of flavone synthase gene expression.

Black cumin (Nigella sativa) is an important medicinal plant belonging to the Ranunculaceae which produces large diversity of secondary metabolites especially terpenes. Mono (C10) and tri-terpenes (C30) are two major structural classes of terpene compounds. Several genes are involved in biosynthetic pathway of the monoterpenes known as MEP pathway، located in plastids. In the MEP pathway، monoterpene synthases are rate- limiting enzymes for monoterpene biosynthesis. In the biosynthetic pathway of monoterpenes geranyl diphosphate synthase catalyzing geranyl diphosphate (GDP) biosynthesis as universal precursor of monoterpenes. Oxidosqualenecyclases is of the most important. In this study gene expression patterns of a monoterpene synthase، GDP synthase، beta amirin synthase and squalene oxidase were evaluated under salicylic acid treatment. Gene expression analysis of the genes at trasnscript level using semi-quantitative PCR in response to salicylic acid treatment revealed their differential expression.

Nowadays plant cell suspension cultures have become an attractive source for secondary metabolites production. The fluorescent compounds are highly valuable in a variety of fields including environmental chemistry and medical and food industries. In this study the cell suspension cultures of black zira, an important medicinal plant in Iran, was established in MS liquid medium supplemented with 2 mg/l NAA and 0.5 mg/l BA. For isolation and identification of fluorescent compound in cell suspension culture samples, 100 gr dried cell with 100 mL dichloromethane was extracted followed by subjecting on a column chromatography and then preparative TLC. The mobile phase was selected as dichloromethane-methanol; 9:1. The TLC comparison of extracts from different parts of the plant (seed, stem, leaf and root) as well as cell suspension culture samples showed that under UV light 365, a blue fluorescent component is present in cell samples whereas nothing was found in the extracts of arial parts of the plant. It is also found that a little fluorescent component has been released into the medium. Results of this study demonstrated the fluorescent component content in callus is less than cell samples under the same conditions. This compound was identified by Nuclear Magnetic Resonance analysis as one of the coumarin derivatives (6-methoxy 7-hydroxy coumarin). Substitutions a methyl group or hydroxyl on the coumarin structure shifted the fluorescent band.