Metabolic and Transcriptomic Profile Revealing the Differential Accumulating Mechanism in Different Parts of Dendrobium nobile.

Dendrobium nobile is an important orchid plant that has been used as a traditional herb for many years. For the further pharmaceutical development of this resource, a combined transcriptome and metabolome analysis was performed in different parts of D. nobile. First, saccharides, organic acids, amino acids and their derivatives, and alkaloids were the main substances identified in D. nobile. Amino acids and their derivatives and flavonoids accumulated strongly in flowers; saccharides and phenols accumulated strongly in flowers and fruits; alkaloids accumulated strongly in leaves and flowers; and a nucleotide and its derivatives and organic acids accumulated strongly in leaves, flowers, and fruits. Simultaneously, genes for lipid metabolism, terpenoid biosynthesis, and alkaloid biosynthesis were highly expressed in the flowers; genes for phenylpropanoids biosynthesis and flavonoid biosynthesis were highly expressed in the roots; and genes for other metabolisms were highly expressed in the leaves. Furthermore, different members of metabolic enzyme families like cytochrome P450 and 4-coumarate-coA ligase showed differential effects on tissue-specific metabolic accumulation. Members of transcription factor families like AP2-EREBP, bHLH, NAC, MADS, and MYB participated widely in differential accumulation. ATP-binding cassette transporters and some other transporters also showed positive effects on tissue-specific metabolic accumulation. These results systematically elucidated the molecular mechanism of differential accumulation in different parts of D. nobile and enriched the library of specialized metabolic products and promising candidate genes.

Revealing of Intracellular Antioxidants in Dendrobium nobile by High Performance Liquid Chromatography-Tandem Mass Spectrometry.

The medicinal plant Dendrobium nobile is an important natural antioxidant resource. To reveal the antioxidants of D. nobile, high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was employed for metabolic analysis. The H2O2-induced oxidative damage was used in human embryonic kidney 293T (H293T) cells to assess intracellular antioxidant activities. Cells incubated with flower and fruit extracts showed better cell survival, lower levels of reactive oxygen species (ROS), and higher catalase and superoxide dismutase activities than those incubated with root, stem, and leaf extracts (p < 0.01). A total of 13 compounds were newly identified as intracellular antioxidants by association analysis, including coniferin, galactinol, trehalose, beta-D-lactose, trigonelline, nicotinamide-N-oxide, shikimic acid, 5'-deoxy-5'-(methylthio)adenosine, salicylic acid, isorhamnetin-3-O-neohespeidoside, methylhesperidin, 4-hydroxybenzoic acid, and cis-aconitic acid (R2 > 0.8, Log2FC > 1, distribution > 0.1%, and p < 0.01). They showed lower molecular weight and higher polarity, compared to previously identified in vitro antioxidants in D. nobile (p < 0.01). The credibility of HPLC-MS/MS relative quantification was verified by common methods. In conclusion, some saccharides and phenols with low molecular weight and high polarity helped protect H293T cells from oxidative damage by increasing the activities of intracellular antioxidant enzymes and reducing intracellular ROS levels. The results enriched the database of safe and effective intracellular antioxidants in medicinal plants.

Paenibacillus dendrobii sp. nov., an indole-3-acetic acid-producing endophytic bacterium isolated from Dendrobium nobile.

A novel rod-shaped, Gram-stain-positive, spore-forming and motile by peritrichous flagella strain, designated HJL G12T, was isolated from the root of Chinese herb Dendrobium nobile. Strain HJL G12T grew optimally at pH 7.0, 30 °C and in the presence of 1.0 % NaCl (w/v). Phylogenetic analysis based on 16S rRNA gene and genomic sequences showed that HJL G12T clustered with Paenibacillus chibensis NBRC 15958T and Paenibacillus dokdonensis YH-JAE5T with 98.3 and 98.2 % sequence similarity. The DNA-DNA hybridization values between strain HJL G12T and the two reference strains were 23.6 % and 24.9 %, respectively. Menaquinone-7 was the only respiratory quinone and meso-diaminopimelic acid was present in the cell-wall peptidoglycan. Antesio-C15 : 0 and iso-C16 : 0 were detected to be the major cellular fatty acids. The cellular polar lipid profile contained diphosphatidyglycerol, phosphatidylglycerol, phosphatidylethanolamine, lysyl-phospatidylglycerol and three unidentified aminophospholipids. Based on these results, strain HJL G12T is considered to represent a novel species within the genus Paenibacillus, for which the name Paenibacillus dendrobii sp. nov. is proposed, with HJL G12T (=NBRC 115617T=CGMCC 1.18520T) as the type strain.

As a novel anticancer candidate, ether extract of Dendrobium nobile overstimulates cellular protein biosynthesis to induce cell stress and autophagy.

Increasing data has confirmed the potential anticancer properties of Dendrobium, a traditional Chinese herb. However, most anticancer compositions from the plant of Dendrobium were usually extracted by high polar solvent, while weak polar compositions with excellent anticancer activity remained largely unexplored. In this study, the differences between ether extract and ethanol extract of Dendrobium nobile Lindl. on chemical components and anticancer activities were investigated, as well as the anticancer mechanisms among different extracts. The results demonstrated that the ether extract exhibited a stronger anticancer effect than ethanol extract, and its anticancer effect was mainly due to weak polar compounds rather than polysaccharides and alkaloids. Quantitative proteomics suggested that the ether extract significantly stimulated the over-expression of immature proteins, the endoplasmic reticulum stress and unfolded protein response were subsequently induced, the intracellular reactive oxygen species level was seriously elevated, and oxidative stress occurred in the meanwhile. Eventually, autophagy and apoptosis were activated to cause cell death. Our findings demonstrate that the ether extract of D. nobile is a potential candidate for anticancer drug development, and that future research on anticancer drugs derived from medicinal plants should also concentrate on weak polar compounds.

Multi-Omics Uncover the Mechanism of Wheat under Heavy Metal Stress.

Environmental pollution of heavy metals has received growing attention in recent years. Heavy metals such as cadmium, lead and mercury can cause physiological and morphological disturbances which adversely affect the growth and quality of crops. Wheat (Triticum aestivum L.) can accumulate high contents of heavy metals in its edible parts. Understanding wheat response to heavy metal stress and its management in decreasing heavy metal uptake and accumulation may help to improve its growth and grain quality. Very recently, emerging advances in heavy metal toxicity and phytoremediation methods to reduce heavy metal pollution have been made in wheat. Especially, the molecular mechanisms of wheat under heavy metal stress are increasingly being recognized. In this review, we focus on the recently described epigenomics, transcriptomics, proteomics, metabolomics, ionomics and multi-omics combination, as well as functional genes uncovering heavy metal stress in wheat. The findings in this review provide some insights into challenges and future recommendations for wheat under heavy metal stress.

Quantitative Identification of Antioxidant Basis for Dendrobium Nobile Flower by High Performance Liquid Chromatography-Tandem Mass Spectrometry.

Dendrobium nobile is a beautiful orchid and a widely used medicinal plant. In vitro antioxidant assays suggested that D. noblie flower extracts showed significantly higher 2, 2'-azinobis-3-ethylbenzthiazoline-6-sulfonate (ABTS) and 1, 1-diphenyl-2-picrylhydrazyl (DPPH) scavenging rates and much more ferric-reducing power than those of root, stem, leaf and fruit. To better understand the antioxidant basis of D. nobile flower, high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) was used for metabolic identification and quantification. Finally, there were 72 metabolites among the total of 712 identified components showed significant association (coefficient >0.8, p < 0.05) with ABTS scavenging rates, DPPH scavenging rates, and ferric-reducing power. The three enriched classes of flower metabolites, including amino acids and their derivatives, organic acids and their derivatives, and flavonoids, formed the main antioxidant basis. The significantly accumulated rutin, astragalin, isomucronulatol-7-O-glucoside, quercetin 4'-O-glucoside, methylquercetin O-hexoside, caffeic acid, caffeic acid O-glucoside, and p-coumaric acid (Log2(fold change) >2, p < 0.01, distribution in flower >0.1%) made a key contribution to the higher antioxidant activities in flower. The relative quantification results of HPLC-MS/MS were verified by the common quantification methods. The antioxidant basis revealed of D. nobile flower will be helpful in the production of healthy or beauty products.

[Correlation analysis and breeding application of agronomic traits and quality indexes in Dendrobium nobile].

The present study aimed to explore the correlation between agronomic traits and quality indexes of Dendrobium nobile and its application value in agricultural breeding. The cultivated strains of D. nobile in Hejiang-Chishui producing areas were extensively collected,and the main agronomic traits and quality indexes were measured. The agronomic traits with significant correlation with quality indexes were screened out by the correlation analysis,and then the parental lines and self-bred F_1 generation plants were furtherverified. Among 96 lines of D. nobile,the content of soluble polysaccharides showed a significant negative correlation with dendrobine( P < 0. 01),and no significant correlation with agronomic traits in stems and leaves. The content of dendrobine exhibited a significant positive correlation with the stem width-thickness ratio( at the largest cross section; P < 0. 01),and no significant correlation with other agronomic traits. Regression analysis further verified the positive correlation between dendrobine content and stem width-thickness ratio( R2> 0. 9). Two lines,JC-10 and JC-35,with significant differences in stem width-thickness ratio were screened out( P <0. 05). The corresponding F1 generation plants by self-pollination both showed that the dendrobine content was higher with greater stem width-thickness ratio( P < 0. 01). The experimental results suggested that within a certain range,the dendrobine content was higher in D. nobile with flatter stem. Therefore,in the breeding of D. nobile,this specific trait could be used for screening plants with high content of quality indexes such as dendrobine.

Molecular mapping of a novel lesion mimic gene (lm4) associated with enhanced resistance to stripe rust in bread wheat.

BACKGROUND: Lesion mimics (LMs) are disease-like symptoms that occur randomly on plant green leaves in the absence of pathogens. A previous study showed that LMs are related to enhanced resistance to a broad spectrum of diverse pathogen races and programmed cell death (PCD). Stripe rust is a globally epidemic fungal disease that can substantially reduce the quality and yield of crops. The development of resistant cultivars is an economical and environmentally friendly way to enhance the adaptability and yield stability of crops instead of the use of fungicide applications. RESULTS: In this study, a novel LM gene affording Pst resistance was identified and mapped with molecular markers developed for marker-assisted selection (MAS)-based wheat breeding. In this study, a novel LM gene named lm4, which is closely linked (8.06 cM) to SSR markers Xgwm210 and Xgwm455, was identified by using a Yanzhan 1/Neixiang 188 RIL population. The genetic distance of lm4 was then narrowed such that it was flanked by SSR markers with 0.51 cM and 0.77 cM intervals. Two SSR markers, lm4_01_cib and lm4_02_cib, were developed based on the content in the Chinese Spring genome database and wheat 660 K SNP results; these markers can be used to conduct MAS of LMs in wheat. The results also showed that lm4 significantly improved the resistance of stripe rust in wheat. CONCLUSIONS: Therefore, lm4 is associated with stripe rust resistance, which may provide theoretical support for future crop disease-resistance breeding and for understanding the plant apoptosis mechanism.

Dendrobium liquor eliminates free radicals and suppresses cellular proteins expression disorder to protect cells from oxidant damage.

Dendrobium liquor obtained by soaking Dendrobium in Chinese liquor is considered as a health drink in China. Here, we found the pretreatment of extract of Dendrobium nobile Lindl. liquor (DNLE) attenuated the oxidative damage to cells caused by H2 O2 , while the abilities of DNLE of eliminating extracellular free radicals and promoting the activities of intracellular antioxidant enzymes were observed. Quantitative proteomics identified 375 differentially expressed proteins caused by H2 O2 treatment in 293T cells. However, only 12 differentially expressed proteins were found in DNLE-pretreated cells which under the same oxidative damage. This suggested that the pretreatment of DNLE could suppress the disorder of protein expressions caused by oxidative stress which could induce cell death. Besides, DNLE was helpful for avoiding the unfolded protein response (UPR) and cell cycle disorder caused by oxidative stress. Taken together, these results demonstrated that Dendrobium liquor could be a healthy herbal drink with antioxidant function. PRACTICAL APPLICATIONS: Dendrobium is used as an edible herb and a tonic food in traditional Chinese medicine. Dendrobium liquor obtained by soaking Dendrobium with Chinese liquor is also regarded as a nourishing health drink. However, there is rare research data on biological activity of Dendrobium liquor. Our current results demonstrated that the extract of Dendrobium nobile Lindl. liquor (DNLE) possessed the ability of eliminating free radicals in/out the human cells. More importantly, DNLE could help cells to resist the interference on cell life activities caused by oxidative stress. Since many evidences suggested that oxidative stress is linked to human disease and aging, and chemical antioxidant has some side effects on health, Dendrobium liquor can serve as a natural health drink with antioxidant function. Furthermore, the active ingredients in DNLE also possess the potential to be developed as natural antioxidant additive in food and cosmetics.

Quantitative assessment of secondary metabolites and cancer cell inhibiting activity by high performance liquid chromatography fingerprinting in Dendrobium nobile.

Dendrobium nobile is an important medicinal food beneficial for human health, well known for polysaccharides and dendrobine. For fast, accurate, and comprehensive comparison of its quality, high performance liquid chromatography (HPLC) fingerprinting method was constructed. Firstly, spring frost stressed D. nobile herb was observed for assessment. Decreased leaf thickness, chlorophyll, and drying rate, and increased free-proline indicated heavy damages on growth. But, the content of polysaccharides increased significantly in during-frost (DF), and dropped significantly in after-frost (AF). The content of dendrobine accumulated significantly in AF. Then, low similarity among HPLC fingerprints of before-frost (BF), DF, and AF, and 75.82% of significantly variant peaks indicated the changing of much more components. Especially, some less-polar components increased significantly in DF, but not in AF. Moreover, the highest suppression rates (SRs) to A549 lung cancer cells were up to 33.08% in DF, but only 15.63% and 12.12% in BF and AF. After association analysis, eleven less-polar components were found to be significantly and positively correlated to SRs under relatively high concentration. The result shows that frost stress not only causes damages to plant growth, but also promotes the accumulation of some health-beneficial bioactive metabolites. HPLC based fingerprinting method shows good applicability on quality evaluation and bioactivity correlation analysis of complexed agricultural products.

Comparative profiling of roots small RNA expression and corresponding gene ontology and pathway analyses for low- and high-cadmium-accumulating genotypes of wheat in response to cadmium stress.

MicroRNAs (miRNAs) participate in multiple biological processes in plant. Cd accumulation ability differs among varieties in wheat, but little is known about miRNAs and their function in Cd accumulation of wheat under Cd stress. Therefore, the present study detected small RNAs responsible for differential Cd accumulation between two contrasting wheat genotypes (low-Cd accumulation one L17 and high-Cd accumulation one H17) to identify novel targets to further study Cd stress in wheat. Under normal conditions, 139 miRNAs were differentially expressed between L17 and H17, while this value reached 142 after Cd exposure. For Cd-induced DEMs, total 25 miRNAs were differentially expressed in L17 after Cd treatment, while, 70 Cd-induced DEMs were found in H17. Moreover, GO analysis revealed that target genes of DEMs related to lipid biosynthetic process and chlorophyll binding are uniquely enriched in L17, target genes of DEMs related to ribosome biogenesis and sucrose alpha-glucosidase activity are uniquely enriched in H17. By pathway analysis, target genes of DEMs related to PI3K-Akt signaling pathway was specifically enriched in L17, target genes of DEMs related to carbohydrate digestion and absorption pathway was uniquely enriched in H17. In addition, miRNA-gene co-expression showed that tae-miR9774 was uniquely expressed between L17Cd and L17CK, while tae-miR398 was specially expressed between H17Cd and H17CK. Our results suggested that Cd-accumulating ability of L17 and H17 varied from the expression of induced unique miRNA, such as expression of tae-miR-9774 and tae-miR-398. Our study not only provide the foundation for further exploring the miRNAs-induced molecular mechanisms of Cd accumulation in wheat but also supply novel strategies for improving phytoremediation ability of food plants through genetic engineering.

The genome-wide impact of cadmium on microRNA and mRNA expression in contrasting Cd responsive wheat genotypes.

BACKGROUND: Heavy metal ATPases (HMAs) are responsible for Cd translocation and play a primary role in Cd detoxification in various plant species. However, the characteristics of HMAs and the regulatory mechanisms between HMAs and microRNAs in wheat (Triticum aestivum L) remain unknown. RESULTS: By comparative microRNA and transcriptome analysis, a total three known and 19 novel differentially expressed microRNAs (DEMs) and 1561 differentially expressed genes (DEGs) were found in L17 after Cd treatment. In H17, by contrast, 12 known and 57 novel DEMs, and only 297 Cd-induced DEGs were found. Functional enrichments of DEMs and DEGs indicate how genotype-specific biological processes responded to Cd stress. Processes found to be involved in microRNAs-associated Cd response include: ubiquitin mediated proteolysis, tyrosine metabolism, and carbon fixation pathways and thiamine metabolism. For the mRNA response, categories including terpenoid backbone biosynthesis and phenylalanine metabolism, and photosynthesis - antenna proteins and ABC transporters were enriched. Moreover, we identified 32 TaHMA genes in wheat. Phylogenetic trees, chromosomal locations, conserved motifs and expression levels in different tissues and roots under Cd stress are presented. Finally, we infer a microRNA-TaHMAs expression network, indicating that miRNAs can regulate TaHMAs. CONCLUSION: Our findings suggest that microRNAs play important role in wheat under Cd stress through regulation of targets such as TaHMA2;1. Identification of these targets will be useful for screening and breeding low-Cd accumulation wheat lines.

Genome-wide identification, phylogenetic and expression analysis of the heat shock transcription factor family in bread wheat (Triticum aestivum L.).

BACKGROUND: Environmental toxicity from non-essential heavy metals such as cadmium (Cd), which is released from human activities and other environmental causes, is rapidly increasing. Wheat can accumulate high levels of Cd in edible tissues, which poses a major hazard to human health. It has been reported that heat shock transcription factor A 4a (HsfA4a) of wheat and rice conferred Cd tolerance by upregulating metallothionein gene expression. However, genome-wide identification, classification, and comparative analysis of the Hsf family in wheat is lacking. Further, because of the promising role of Hsf genes in Cd tolerance, there is need for an understanding of the expression of this family and their functions on wheat under Cd stress. Therefore, here we identify the wheat TaHsf family and to begin to understand the molecular mechanisms mediated by the Hsf family under Cd stress. RESULTS: We first identified 78 putative Hsf homologs using the latest available wheat genome information, of which 38 belonged to class A, 16 to class B and 24 to class C subfamily. Then, we determined chromosome localizations, gene structures, conserved protein motifs, and phylogenetic relationships of these TaHsfs. Using RNA sequencing data over the course of development, we surveyed expression profiles of these TaHsfs during development and under different abiotic stresses to characterise the regulatory network of this family. Finally, we selected 13 TaHsf genes for expression level verification under Cd stress using qRT-PCR. CONCLUSIONS: To our knowledge, this is the first report of the genome organization, evolutionary features and expression profiles of the wheat Hsf gene family. This work therefore lays the foundation for targeted functional analysis of wheat Hsf genes, and contributes to a better understanding of the roles and regulatory mechanism of wheat Hsfs under Cd stress.

[Quantitative proteomics of inhibitory mechanism of Dendrobium denneanum ether extract on lung cancer cells].

Dendrobium denneanum have been used for a long time as rare medicinal herbs in traditional Chinese medicine. Our previous works found that ether extract of D. denneanum had higher anticancer activities than alcohol or water extract,thus with better development prospects. Quantitative proteomics based on SILAC technique was used to investigate the anticancer mechanism of D. denneanum on lung tumor cell line A549,and 4 855 proteins were detected in A549 cells. Quantitative proteomics experiments found that 193 proteins of A549 cells were up-regulated,and 44 proteins were down-regulated by ether extract of D. denneanum. Those proteins are associated with synthesis,transport and metabolism of biological macromolecules,chaperone,DNA repair,oxidoreductase,cell adhesion,cell cycle,apoptosis and autophagy. Through the function analysis of differentially expressed proteins,it was inferred that ether extract of D. denneanum caused cell protein metabolism disorder,endoplasmic reticulum stress response,abnormal self-repair mechanism of cells,damage of cell adhesion and proliferation; besides,it caused a dramatic increase in ROS level in A549 cells,and upset the balance of intracellular oxidation reduction system. Affected by the above factors,lung cancer cells initiated apoptosis and autophagy,which accelerated cell death. This research explains the anticancer mechanism of D. denneanum from the perspective of quantitative proteomics,and lays a foundation for future research and development of new anticancer drugs based on ether extract of D. denneanum.

Comparative analysis of root transcriptome profiles between low- and high-cadmium-accumulating genotypes of wheat in response to cadmium stress.

Wheat, one of the most broadly cultivated and consumed food crops worldwide, can accumulate high Cd contents in their edible parts, which poses a major hazard to human health. Cd accumulation ability differs among varieties in wheat, but the underlying molecular mechanism is largely unknown. Here, key genes responsible for Cd accumulation between two contrasting wheat genotypes (low-Cd accumulation one L17, high-Cd accumulation one H17) were investigated. Total 1269 were differentially expressed genes (DEGs) in L17 after Cd treatment, whereas, 399 Cd-induced DEGs were found in H17. GO-GO network analysis showed that heme binding was the most active GO, and metal binding was the second one that associated with other GOs in response to Cd stress in both genotypes. Pathway-pathway network analysis showed that phenylpronanoid biosynthesis and glutathione metabolism were the top pathways in response to Cd stress in both genotypes. Furthermore, we found that DEGs related to ion binding, antioxidant defense mechanisms, sulfotransferase activity, and cysteine biosynthetic process were more enriched in L17. In conclusion, our results not only provide the foundation for further exploring the molecular mechanism of Cd accumulation in wheat but also supply new strategies for improving phytoremediation ability of wheat by genetic engineering.

Genome-wide researches and applications on Dendrobium.

MAIN CONCLUSION: This review summarizes current knowledge of chromosome characterization, genetic mapping, genomic sequencing, quality formation, floral transition, propagation, and identification in Dendrobium. The widely distributed Dendrobium has been studied for a long history, due to its important economic values in both medicine and ornamental. In recent years, some species of Dendrobium and other orchids had been reported on genomic sequences, using the next-generation sequencing technology. And the chloroplast genomes of many Dendrobium species were also revealed. The chromosomes of most Dendrobium species belong to mini-chromosomes, and showed 2n = 38. Only a few of genetic studies were reported in Dendrobium. After revealing of genomic sequences, the techniques of transcriptomics, proteomics and metabolomics could be employed on Dendrobium easily. Some other molecular biological techniques, such as gene cloning, gene editing, genetic transformation and molecular marker developing, had also been applied on the basic research of Dendrobium, successively. As medicinal plants, insights into the biosynthesis of some medicinal components were the most important. As ornamental plants, regulation of flower related characteristics was the most important. More, knowledge of growth and development, environmental interaction, evolutionary analysis, breeding of new cultivars, propagation, and identification of species and herbs were also required for commercial usage. All of these studies were improved using genomic sequences and related technologies. To answer some key scientific issues in Dendrobium, quality formation, flowering, self-incompatibility and seed germination would be the focus of future research. And genome related technologies and studies would be helpful.

Detection and Categorization of Diarrheagenic Escherichia coli with Auto-microfluidic Thin-film Chip Method.

Diarrheagenic Escherichia coli (DEC) causes human diarrhea symptom in both healthy and immunocompromised individuals. An auto-microfluidic thin-film chip (AMTC) instrument integrating one-step multiplex PCR (mPCR) with reverse dot blot hybridization (RDBH) was developed for high-throughput detection of DEC. The novel mPCR method was developed by designing 14 specific primers and corresponding probes. 14 indexes including an endogenous gene (uidA) and 13 pathogenic genes (stx1, stx2, escV, ipaH, invE, estB, lt, pic, aggR, astA, bfpB, sth and stp) of DEC were detected. This one-step mPCR + RDBH approach is useful for simultaneous detection of numerous target genes in a single sample, whose specificity and availability have been confirmed on the positive control of 11 DEC strains. In addition, with 300 diarrheal stool samples being detected by this method, 21 were found to contain five major DEC strains. Compared with monoplex PCR and previous one-step mPCR approach, this method could detect ipaH and estB, and compared with current commercial kit, the relevance ratio of DEC detected by the AMTC method was increased by 1% in stool samples. Furthermore, the novel integration AMTC device could be a valuable detection tool for categorization of E. coli.

Evaluating the Effect of Expressing a Peanut Resveratrol Synthase Gene in Rice.

Resveratrol (Res) is a type of natural plant stilbenes and phytoalexins that only exists in a few plant species. Studies have shown that the Res could be biosynthesized and accumulated within plants, once the complete metabolic pathway and related enzymes, such as the key enzyme resveratrol synthase (RS), existed. In this study, a RS gene named PNRS1 was cloned from the peanut, and the activity was confirmed in E. coli. Using transgenic approach, the PNRS1 transgenic rice was obtained. In T3 generation, the Res production and accumulation were further detected by HPLC. Our data revealed that compared to the wild type rice which trans-resveratrol was undetectable, in transgenic rice, the trans-resveratrol could be synthesized and achieved up to 0.697 µg/g FW in seedlings and 3.053 µg/g DW in seeds. Furthermore, the concentration of trans-resveratrol in transgenic rice seedlings could be induced up to eight or four-fold higher by ultraviolet (UV-C) or dark, respectively. Simultaneously, the endogenous increased of Res also showed the advantages in protecting the host plant from UV-C caused damage or dark-induced senescence. Our data indicated that Res was involved in host-defense responses against environmental stresses in transgenic rice. Here the results describes the processes of a peanut resveratrol synthase gene transformed into rice, and the detection of trans-resveratrol in transgenic rice, and the role of trans-resveratrol as a phytoalexin in transgenic rice when treated by UV-C and dark. These findings present new outcomes of transgenic approaches for functional genes and their corresponding physiological functions, and shed some light on broadening available resources of Res, nutritional improvement of crops, and new variety cultivation by genetic engineering.

[Advances of resveratrol synthase gene in the application of genetic engineering and biofunctional investigation].

Resveratrol synthase (RS) plays a key role in resveratrol (Res) biosynthesis. RS gene has been formerly reported to be transformed into many plant species and microorganisms, and to play certain roles in metabolic and regulation processes. In this paper, the transformations of RS gene in plants, and the related changes of biological properties, such as metabolites, anti-pathogen activities, anti-radical properties, and developmental characters in transgenic plants, as well as the production of resveratrol in microbes by utilizing RS gene were summarized. Moreover, the application prospects of RS gene in bioengineering were also addressed.