Production Of Important Secondary Metabolites Research Articles

Elicitation Induced α-Amyrin Synthesis in Tylophora indica In Vitro Cultures and Comparative Phytochemical Analyses of In Vivo and Micropropagated Plants.

Tylophora indica (Burm. f.) Merrill is an endangered medicinal plant that possesses various active agents, such as tylophorinine, kaempferol, quercetin, α-amyrin and beta-sitosterol, with multiple medicinal benefits. α-amyrin, a triterpenoid, is widely known for its antimicrobial, anti-inflammatory, gastroprotective and hepatoprotective properties. In this study, we investigated the metabolite profiling of tissues and the effects of cadmium chloride and chitosan on in vitro accumulation of alkaloids in T. indica. First, the callus was induced from the leaf in 2,4-D-, NAA- and/or BAP-fortified MS medium. Subsequent shoot formation through organogenesis and in vitro roots was later induced. Gas chromatography-mass spectrometry (GC-MS)-based phytochemical profiling of methanolic extracts of in vivo and in vitro regenerated plants was conducted, revealing the presence of the important phytocompounds α-amyrin, lupeol, beta-sitosterol, septicine, tocopherol and several others. Different in vitro grown tissues, like callus, leaf and root, were elicited with cadmium chloride (0.1-0.4 mg L-1) and chitosan (1-50 mg L-1) to evaluate the effect of elicitation on α-amyrin accumulation, measured with high-performance thin layer chromatography (HPTLC). CdCl2 and chitosan showed improved sugar (17.24 and 15.04 mg g-1 FW, respectively), protein (10.76 and 9.99 mg g-1 FW, respectively) and proline (7.46 and 7.12 mg g-1 FW), especially at T3 (0.3 and 25 mg L-1), in the leaf as compared to those of the control and other tissues. The antioxidant enzyme activities were also evaluated under an elicitated stress situation, wherein catalase (CAT), superoxide dismutase (SOD) and ascorbate peroxidase (APX) displayed the highest activities in the leaf at T4 of both of the two elicitors. The α-amyrin yield was quantified with HPTLC in all tested tissues (leaf, callus and root) and had an Rf = 0.62 at 510 nm wavelength. Among all the concentrations tested, the T3 treatment (0.3 mg L-1 of cadmium chloride and 25 mg L-1 of chitosan) had the best influence on accumulation, irrespective of the tissues, with the maximum being in the leaf (2.72 and 2.64 μg g-1 DW, respectively), followed by the callus and root. Therefore, these results suggest future opportunities of elicitors in scaling up the production of important secondary metabolites to meet the requirements of the pharmaceutical industry.

Nanotechnology in Plant Metabolite Improvement and in Animal Welfare

Plant tissue culture plays an important role in plant biotechnology due to its potential for massive production of improved crop varieties and high yield of important secondary metabolites. Several efforts have been made to ameliorate the effectiveness and production of plant tissue culture, using biotic and abiotic factors. Nowadays, the addition of nanoparticles as elicitors has, for instance, gained worldwide interest because of its success in microbial decontamination and enhancement of secondary metabolites. Nanoparticles are entities in the nanometric dimension range: they possess unique physicochemical properties. Among all nanoparticles, silver-nanoparticles (AgNPs) are well-known for their antimicrobial and hormetic effects, which in appropriate doses, led to the improvement of plant biomass as well as secondary metabolite accumulation. This review is focused on the evaluation of the integration of nanotechnology with plant tissue culture. The highlight is especially conveyed on secondary metabolite enhancement, effects on plant growth and biomass accumulation as well as their possible mechanism of action. In addition, some perspectives of the use of nanomaterials as potential therapeutic agents are also discussed. Thus, the information provided will be a good tool for future research in plant improvement and the large-scale production of important secondary metabolites. Elicitation of silver-nanoparticles, as well as nanomaterials, function as therapeutic agents for animal well-being is expected to play a major role in the process. However, nanosized supramolecular aggregates have received an increased resonance also in other fields of application such as animal welfare. Therefore, the concluding section of this contribution is dedicated to the description and possible potential and usage of different nanoparticles that have been the object of work and expertise also in our laboratories.

Dark side of cyanobacteria: searching for strategies to control blooms.

SummaryCyanobacteria are ecologically one of the most prolific groups of photosynthetic prokaryotes in marine and freshwater habitats. They are primary producer microorganisms and are involved in the production of important secondary metabolites, including toxic compounds such as cyanotoxins. Environmental conditions promote massive growth of these microbes, causing blooms that can have critical ecological and public health implications. In this highlight, we discuss some of the approaches being addressed to prevent these blooms, such as control of nutrient loading, treatments to minimize growth or monitoring interactions with other species.

Review: Regulation of Phytohormones and Environmental Stresses to Increase the Production of Plant Secondary Metabolites

Secondary metabolites are synthesized by plants when subjected to abiotic and biotic stresses as a defense mechanism and play an ecologically vital role both as pollination attractants and as repellents. These compounds are not essential for the process of growth and development but provide a significant impact on human welfare in various aspects as pharmaceuticals and therapeutics, aroma and taste, biopesticides, and agrochemicals. This natural product has high economic and commercial value, so it is important to explore it along with the increasing needs of consumers and industry at a large scale. Various extensive studies were carried out to improve and increase the production and accumulation of secondary metabolites. One of the strategies adopted in this review is the role of exogenous phytohormones in triggering the production of important secondary metabolites based on their classification, namely terpenoids, phenols, and flavonoids, as well as alkaloids and nitrogen-containing compounds. Bioregulators work as elicitors to induce the production of secondary metabolites through up-regulation of specific gene expression. In some cases, the application of phytohormones combined with exposure to extreme abiotic stresses showed overexpression of secondary metabolite synthesis compared to treatment with only those subjected to phytohormone. The abiotic stress of irradiation, UV-B, temperature, drought, ultrasonic, salinity, and metal stress was discussed in this study. Oxidative conditions under environmental changes trigger the plant to produce reactive oxygen species (ROS), which induce various secondary metabolites as part of the regulation of antioxidant systems. Micropropagation of medicinal plants by the addition of exogenous growth regulators could enhance the production and accumulation of important secondary metabolites.

The effect of developmental stages of corm, type of medium and plant growth regulators in callus induction of Crocus sativus L.

Purpose: The efficiency of callus induction as source of bioactive compound is a critical step in the cell suspension culture for commercial production of important secondary metabolites. One of the main factors affecting callus efficiency is the developmental stage of explants. On the other hands, it has been declared that the optimization of medium composition has a significant influence on callogenesis and increment of biomass. Research method: The aim of this study was the evaluation of different developmental stages of saffron corms as a source of explant preparation (immature and mature corms), plant growth regulators (PGRs) combinations (1-Naphthaleneacetic acid (NAA); 2, 4-dichlorophenoxyacetic acid (2,4-D); 6-Benzyladenine (BA) and kinetin (Kin)) and type of medium (Gamborg (B5) medium and Murashige and Skoog (MS) medium) in callus induction in saffron corms to increase cell biomass. The media were supplemented with different combinations of 1-Naphthaleneacetic acid or 2, 4-dichlorophenoxyacetic acid (2, 4, 8 mgL-1) as auxins and 6-Benzyladenine or kinetin (1, 4, 8 mgL-1) as cytokinin. Findings: The results showed that mature corms harvested in May had the best developmental stage for callogenesis. The maximum callus formation was recorded in B5 medium supplemented with 2,4-dichlorophenoxyacetic acid (4 mgL-1) and kinetin (1 mgL-1) with 2.61 g fresh weight. Limitations: No limitations to report. Originality/Value: This protocol for sampling explant and callus formation was found to make suitable sources of plant material for further study in production of bioactive compounds via cell suspension cultures.

Chitinase and Glucanase Activities of Antagonistic Streptomyces Spp Isolated From Fired Plots under Shifting Cultivation In Northeast India

Actinobacteria are most widely distributed and distinct group of microorganisms in nature. Actinobacteria, Streptomyces species in particular, has been a broadly exploited group of microorganisms for the production of important secondary metabolites and enzymes in the field of medicine and agriculture.

High Triterpenic Acids Production in Callus Cultures from Fruit Pulp of Two Apple Varieties.

Very rarely fruit pulp has been used in in vitro culture to produce secondary metabolites useful in promoting health. The aims of this work were the study of the best conditions to obtain the callus cultures from the pulp of two varieties of apples, Golden Delicious (GD) and "Mela Rosa Marchigiana" (MRM), and the quali-quantitative analysis of secondary metabolites produced by the two in vitro callus cultures. Callus was induced on both Murashige and Skoog and Gamborg B5 media containing various combinations of supplements. To achieve the maximum recovery of secondary metabolites produced, preliminary extraction tests were carried out on GD apple culture using two different organic solvents (MeOH and EtOAc). The quali-quantitative analysis of the methanolic extract of both cultures was carried out by ESI-MSn and GC-MS techniques. The GC-MS analysis revealed the presence of triterpenic acids, in particular, oleanolic, ursolic, maslinic, pomolic, tormentic, corosolic and annurcoic acid along with a phytosterol, β-sitosterol. In addition, GD callus culture produced phloridzin, absent in the MRM culture. In this last culture, however, the total amount of secondary metabolites was markedly higher. The in vivo production of these bioactive compounds were also quantified in the GD and MRM apple pulps. Apple pulps produced higher amounts of triterpenic acids in vitro than in vivo. The present work can be considered a method to amplify the production of important secondary metabolites which exert beneficial effects on human health. Copyright © 2016 John Wiley & Sons, Ltd.

Construction of a high-density genetic map and lint percentage and cottonseed nutrient trait QTL identification in upland cotton (Gossypium hirsutum L.).

Upland cotton plays a critical role not only in the textile industry, but also in the production of important secondary metabolites, such as oil and proteins. Construction of a high-density linkage map and identifying yield and seed trait quantitative trail loci (QTL) are prerequisites for molecular marker-assisted selective breeding projects. Here, we update a high-density upland cotton genetic map from recombinant inbred lines. A total of 25,313 SSR primer pairs were screened for polymorphism between Yumian 1 and T586, and 1712 SSR primer pairs were used to genotype the mapping population and construct a map. An additional 1166 loci have been added to our previously published map with 509 SSR markers. The updated genetic map spans a total recombinant length of 3338.2cM and contains 1675 SSR loci and nine morphological markers, with an average interval of 1.98cM between adjacent markers. Green lint (Lg) mapped on chromosome 15 in a previous report is mapped in an interval of 2.6cM on chromosome 21. Based on the map and phenotypic data from multiple environments, 79 lint percentage and seed nutrient trait QTL are detected. These include 8 lint percentage, 13 crude protein, 15 crude oil, 8 linoleic, 10 oleic, 13 palmitic, and 12 stearic acid content QTL. They explain 3.5-62.7% of the phenotypic variation observed. Four morphological markers identified have a major impact on lint percentage and cottonseed nutrients traits. In this study, our genetic map provides new sights into the tetraploid cotton genome. Furthermore, the stable QTL and morphological markers could be used for fine-mapping and map-based cloning.

Development of a rapid and high frequency Agrobacterium rhizogenes mediated transformation protocol for Ocimum tenuiflorum

A rapid and efficient Agrobacterium rhizogenes mediated transformation system for Ocimum tenuiflorum L., a traditional Indian medicinal plant that occurs in red and green forma, was developed. The plant is a repertoire of several pharmaceutically and nutraceutically important metabolites. Three different types of explants i.e. leaves, hypocotyls and excised shoots, obtained from shoot cultures of in vitro germinated red and green forma plants were transformed using Agrobacterium rhizogenes strain ATCC 15834. The transformation efficiency was equal between similar explants of both forma. Transformation efficiency was best in leaves of 4 days while excised shoots and hypocotyls had 6 and 8 days respectively. Transformation frequency of green forma leaves was the highest (70.6%) among all explants. Excised shoots of green forma plants exhibited better transformation (58.3%) than the red forma excised shoots (42.59%). Red forma hypocotyl explants displayed marginally better (26.27%) transformation frequency than green hypocotyl explants (21.14%). Transformation with hairy root was confirmed by the presence of rolC gene through PCR amplification and Southern hybridization. The development of hairy root-based transgenic system for O. tenuiflorum will pave the way for in vitro production of important secondary metabolites.

DNA Based Identification and Phylogenetic Characterisation of Endophytic and Saprobic Fungi from Antidesma madagascariense, a Medicinal Plant in Mauritius

Endophytes are fungi associated with plants without causing symptoms, and they are quite diverse and have enormous potential for production of important secondary metabolites for the pharmaceutical industry. In this study, we report for the first time fungi (both endophytes and saprobes) from Antidesma madagascariense, a medicinal plant in Mauritius, in view of identifying potential candidates for screening of fungi for pharmaceutical importance. In addition the phylogenetic placement of fungi recovered from leaves samples was investigated based on rDNA sequence analysis. Most commonly isolated fungi were related to Aspergillus, Guignardia, Fusarium, Penicillium, Pestalotiopsis, and Trichoderma. Phylogenetic analyses revealed that fungi recovered belong to 5 different fungal lineages (Hypocreaceae, Trichocomaceae, Nectriaceae, Xylariaceae, and Botryosphaeriaceae). DNA data from the ITS regions were reliable in classification of all recovered isolates up to genus level, but identification to an exact species name was not possible at this stage. Despite criticisms pertaining to the use of ITS sequence data in molecular systematics, our approach here provides an opportunity to justify the reliability of ITS sequence data for possible identification and discovering of evolutionary scenarios among isolates that do not sporulate under cultural conditions.

Over-expression of the transcription factor HlMYB3 in transgenic hop (Humulus lupulus L. cv. Tettnanger) modulates the expression of genes involved in the biosynthesis of flavonoids and phloroglucinols

Genes belonging to the R2R3 MYB transcription factor family play an important role in the regulation of the expression of structural genes involved in the biosynthesis of flavonoids. In this study, the regulatory gene s-HlMYB3 under the control of the CaMV 35S promoter was genetically transformed into hop cv. Tettnanger. This work was aimed at investigating the effect of s-HlMYB3 on the expression of genes involved in the biosynthesis of flavonoids and phloroglucinols. The transgene s-HlMYB3 was stably integrated and expressed in transgenic plants. Quantitative real-time PCR indicated that HlMYB3 was highly over-expressed in transgenic events compared to wildtype plants. The effect of the over-expressed transgene on the expression rate of structural genes of flavonoid and phloroglucinol biosynthesis, such as PAL, C4H, 4CL, CHS_H1, CHI, F3H, F3′H, FLS, F3′5′H, OMT1, HlPT1, and VPS, as well as on regulatory genes of hop like, HlMYB1, HlMYB2, HlMYB7, HlbZip1, HlbZip2, HlbHLH2, and WDR1 was examined. Transgenic events with an elevated expression of genes of flavonoids and phloroglucinols were identified. Chemical analysis revealed higher levels of cohumulone and colupulone in transgenic plants. In hop, flavonoids and phloroglucinols play an important role as flavoring compounds of beer. Moreover, prenylated chalcones (e.g. xanthohumol and desmethylxanthohumol) have received considerable attention because of their pharmacological properties. Metabolic engineering using genes of homologous MYB transcription factors may open the possibility for increasing the production of important secondary metabolites in hop.