Efficient regeneration of mature castanopsis hystrix from in vitro stem explants.

Castanopsis hystrix is one of the main timber trees grown in China. However, severe shortage of natural seeds and the difficulty of explant regeneration has limited seedling supply. As such, there is a need for research on asexual multiplication of C. hystrix. This study established a rapid propagation technology system for C. hystrix genotypes, including explant treatment, proliferation, and rooting. HZ (a modified MS medium) supplemented with 4.4 µM BA and 0.5 µM IBA was found to be the optimal medium for shoot sprouting. The maximum proliferation coefficient and the number of effective shoots was obtained on HZ medium supplemented with 2.6 µM BA and 1.0 µM IBA, were 3.00 and 5.63, respectively. A rooting rate of 83.33% was achieved using half-strength HZ medium supplemented with 3.2 µM NAA. Adding vitamin C (80 mg⋅l-1) for 7 days in a dark environment reduced the browning rate, while increasing the proliferation rate. Additionally, through cytological observation, we established how and where adventitious roots occur. The survival rate of transplanted plantlets was > 90%. This is the first report of an in vitro regeneration technique that uses stem segments of mature C. hystrix as explants.

Hepatoprotective Effect of Oplopanax elatus Nakai Adventitious Roots Extract by Regulating CYP450 and PPAR Signaling Pathway.

O. elatus Nakai is a traditional medicine that has been confirmed to exert effective antioxidant and anti-inflammatory functions, and is used for the treatment of different disorders. However, its potential beneficial effects on drug induced hepatotoxicity and relevant molecular mechanisms remain unclear. This study investigated the protective effect and further elucidated the mechanisms of action of O. elatus on liver protection. O. elatus chlorogenic acids-enriched fraction (OEB), which included chlorogenic acid and isochlorogenic acid A, were identified by HPLC-MS/MS. OEB was administrated orally daily for seven consecutive days, followed by a single intraperitoneal injection of an overdose of APAP after the final OEB administration. The effects of OEB on immune cells in mice liver were analyzed using flow cytometry. APAP metabolite content in serum was detected using HPLC-MS/MS in order to investigate whether OEB affects CYP450 activities. The intestinal content samples were processed for 16 s microbiota sequencing. Results demonstrated that OEB decreased alanine aminotransferase, aspartate aminotransferase contents, affected the metabolism of APAP, and decreased the concentrates of APAP, APAP-CYS and APAP-NAC by inhibiting CYP2E1 and CYP3A11 activity. Furthermore, OEB pretreatment regulated lipid metabolism by affecting the peroxisome proliferator-activated receptors (PPAR) signaling pathway in mice and also increased the abundance of Akkermansia and Parabacteroides. This study indicated that OEB is a potential drug candidate for treating hepatotoxicity because of its ability to affect drug metabolism and regulate lipid metabolism.

Evaluation of growth and some unexplored bioactivities of bioreactor grown adventitious root culture of ginseng (Panax ginseng C.A. Meyer).

The purpose of the present study was to evaluate the growth potential and some rarely reported bioactivities (antioxidant, thrombolytic, anticoagulant, and anthelmintic) of Panax ginseng C.A. Meyer adventitious roots. To demonstrate the growth, shake flask and laboratory-scale bioreactor cultures have been employed. The obtained biomass was dried and extracted with water, ethanol, and methanol. The growth ratio (12.62 ± 1.03) observed in the bioreactor was significantly higher than in the shake flask culture. The presence of 10 different phytochemical classes, including carbohydrates, saponins, glycosides, and terpenoids were detected in qualitative estimation. Significant quantities of phenolics, flavonoids, proteins, and tannins were determined. Dose-dependent antioxidant activities were observed, and the IC50 values of methanolic and ethanolic extracts were very similar to the standard. The highest (29.26 ± 5.31%) thrombolytic potential was shown by the methanolic extract. The ethanolic extract significantly extended the coagulation times up to 2.5 fold. The highest anthelmintic properties in terms of paralyzing (2.21 ± 0.31 min) and killing (3.69 ± 0.41 min) of the parasitic worms were displayed by the aqueous extract. The in vitro root growth implies the commercial feasibility of ginseng production in Bangladesh and the demonstration of potential bioactivities strengthens medicinal implications and also offering new research areas.

Cation transporters in cell fate determination and plant adaptive responses to a low-oxygen environment.

Soil flooding creates low-oxygen environments in root zones and thus severely affects plant growth and productivity. Plants adapt to low-oxygen environments by a suite of orchestrated metabolic and anatomical alterations. Of these, formation of aerenchyma and development of adventitious roots are considered very critical to enable plant performance in waterlogged soils. Both traits have been firmly associated with stress-induced increases in ethylene levels in root tissues that operate upstream of signalling pathways. Recently, we used a bioinformatic approach to demonstrate that several Ca2+ and K+ -permeable channels from KCO, AKT, and TPC families could also operate in low oxygen sensing in Arabidopsis. Here we argue that low-oxygen-induced changes to cellular ion homeostasis and operation of membrane transporters may be critical for cell fate determination and formation of the lysigenous aerenchyma in plant roots and shaping the root architecture and adventitious root development in grasses. We summarize the existing evidence for a causal link between tissue-specific changes in oxygen concentration, intracellular Ca2+ and K+ homeostasis, and reactive oxygen species levels, and their role in conferring those two major traits enabling plant adaptation to a low-oxygen environment. We conclude that, for efficient operation, plants may rely on several complementary signalling pathway mechanisms that operate in concert and 'fine-tune' each other. A better understanding of this interaction may create additional and previously unexplored opportunities to crop breeders to improve cereal crop yield losses to soil flooding.

De novo transcriptome analysis provides insights into formation of in vitro adventitious root from leaf explants of Arnebia euchroma.

BACKGROUND: Adventitious root formation is considered a major developmental step during the propagation of difficult to root plants, especially in horticultural crops. Recently, adventitious roots induced through plant tissue culture methods have also been used for production of phytochemicals such as flavonoids, anthocyanins and anthraquinones. It is rather well understood which horticultural species will easily form adventitious roots, but the factors affecting this process at molecular level or regulating the induction process in in vitro conditions are far less known. The present study was conducted to identify transcripts involved in in vitro induction and formation of adventitious roots using Arnebia euchroma leaves at different time points (intact leaf (control), 3 h, 12 h, 24 h, 3 d, 7 d, 10 d and 15 d). A. euchroma is an endangered medicinal Himalayan herb whose root contains red naphthoquinone pigments. These phytoconstituents are widely used as an herbal ingredient in Asian traditional medicine as well as natural colouring agent in food and cosmetics. RESULTS: A total of 137.93 to 293.76 million raw reads were generated and assembled to 54,587 transcripts with average length of 1512.27 bps and N50 of 2193 bps, respectively. In addition, 50,107 differentially expressed genes were identified and found to be involved in plant hormone signal transduction, cell wall modification and wound induced mitogen activated protein kinase signalling. The data exhibited dominance of auxin responsive (AUXIN RESPONSE FACTOR8, IAA13, GRETCHEN HAGEN3.1) and sucrose translocation (BETA-31 FRUCTOFURANOSIDASE and MONOSACCHARIDE-SENSING protein1) genes during induction phase. In the initiation phase, the expression of LATERAL ORGAN BOUNDARIES DOMAIN16, EXPANSIN-B15, ENDOGLUCANASE25 and LEUCINE-rich repeat EXTENSION-like proteins was increased. During the expression phase, the same transcripts, with exception of LATERAL ORGAN BOUNDARIES DOMAIN16 were identified. Overall, the transcriptomic analysis revealed a similar patterns of genes, however, their expression level varied in subsequent phases of in vitro adventitious root formation in A. euchroma. CONCLUSION: The results presented here will be helpful in understanding key regulators of in vitro adventitious root development in Arnebia species, which may be deployed in the future for phytochemical production at a commercial scale.

Akt activation-dependent protective effect of wild ginseng adventitious root protein against UVA-induced NIH-3T3 cell damage.

Prolonged skin exposure to ultraviolet radiation can lead to development of several acute and chronic diseases, with UVA exposure considered a primary cause of dermal photodamage. We prepared a wild ginseng adventitious root extract (ARE) that could alleviate UVA irradiation-induced NIH-3T3 cell viability decline. After employing a series of purification methods to isolate main active components of ARE, adventitious root protein mixture (ARP) was identified then tested for protective effects against UVA irradiation-induced NIH-3T3 cell damage. The results showed that ARP treatment significantly reduced UVA-induced cell viability decline and confirmed that the active constituent of ARP was the protein, since proteolytic hydrolysis and heat treatment each eliminated ARP protective activity. Moreover, ARP treatment markedly inhibited UVA-induced apoptosis, cell cycle arrest and DNA fragmentation, while also significantly reversing UVA effects (elevated Bax levels, reduced Bcl-2 expression) by reducing Bax levels and increasing Bcl-2 expression. Mechanistically, ARP promoted Akt phosphorylation regardless of UVA exposure, thus confirming ARP resistance to inactivation by UVA light. Notably, in the presence of Akt inhibitor SC0227, ARP could no longer counteract UVA-induced cell viability decline and DNA fragmentation. Additionally, our results demonstrated that ARP treatment protected UVA-irradiated NIH-3T3 cells by preventing UVA-induced reduction of collagen-I expression. Taken together, these results suggest that ARP treatment of NIH-3T3 cells effectively mitigated UVA-induced cell viability decline by activating intracellular Akt to reduce UVA-induced DNA damage, leading to reduced rates of apoptosis and cell cycle arrest after UVA exposure and restoring collagen expression to normal levels.

Morphology, germination, and geographic distribution of Pentaclethra macroloba (Fabaceae): a hyperdominant Amazonian tree / Morfología, germinación y distribución geográfica de Pentaclethra macroloba (Fabaceae): árbol amazónico hiperdominante

Introduction: Pentaclethra macroloba is a hyperdominant tree in the Amazon estuary of great socioeconomic importance for the region because the oil from its seeds is a powerful herbal medicine. Objective: We aimed to characterize the morphological structure, the morphological adaptations in response to the daily flooding of the Amazon estuary and the biogeographic area of P. macroloba. Methods: Detailed description of the external morphology, from germination to the adult tree, was obtained from individuals located in floodplain forest, Northeast Amazonia. The occupation area and the geographical extension of P. macroloba were determined from point of geographical coordinates of botanical samples deposited in the digital collections of Mobot and SpeciesLink. Results: Adult individuals have adapted structures in response to daily flooding, such as: adventitious roots to increase respiratory efficiency and lenticels in the trunk, serving as a connection point for oxygen transport between the root and the aerial part. Dried fruit favours the activation of the explosive dehiscence mechanism, allowing the seed to be expelled long distance. Deltoid shape of the seed allows water fluctuation and more efficient dispersal. Seedling is phanerocotylar hypogeal and with one pair of reserve cotyledons that provide the seedling an extra source of energy to escape the flood. Germination rate was 78 % and the speed was 0.2 seeds.day-1. Circular buffer method revealed the presence of 123 subpopulations of P. macroloba distributed in a radius of 5 699 943 km² across the Neotropical region. Conclusions: Much of the morphological structures of P. macroloba are adaptive and evolutionary responses to the periodically flooded environment of the Amazon estuary, showing that these environments select the trees, best adapted, to inhabit the flood. P. macroloba has a wide geographical area denotes the plasticity of adapting to different environments, which may justify its monodominance in some regions.

Introducción: Pentaclethra macroloba es un árbol hiperdominante en el estuario del Amazonas, de gran importancia socioeconómica para la región, pues el aceite de sus semillas es un poderoso medicamento natural. Objetivo: Nuestro objetivo fue caracterizar la estructura morfológica, las adaptaciones morfológicas en respuesta a las inundaciones diarias del estuario del Amazonas y el área biogeográfica de P. macroloba. Métodos: Una descripción detallada de la morfología externa, desde la germinación hasta el árbol adulto, se obtuvo de individuos ubicados en el bosque periódicamente inundado, al noreste de la Amazonia. El área de ocupación y la extensión geográfica de P. macroloba se determinaron a partir del punto de coordenadas geográficas de muestras botánicas depositadas en las colecciones digitales de Mobot y SpeciesLink. Resultados: Los individuos adultos tienen estructuras adaptadas en respuesta a las inundaciones diarias, tales como: raíces adventicias para aumentar la eficiencia respiratoria y lenticelas en el tronco, que sirven como punto de conexión para el transporte de oxígeno entre la raíz y la parte aérea. Los frutos secos favorecen la activación del mecanismo de dehiscencia explosiva, permitiendo que la semilla sea expulsada a larga distancia. La forma deltoidea de la semilla permite la fluctuación en el agua y una dispersión más eficiente. La plántula es hipogel fanerocotiledones y con un par de cotiledones de reserva que proporcionan a la plántula una fuente extra de energía para escapar de la inundación. La tasa de germinación fue del 78 % y la velocidad fue de 0.2 semillas día-1. El método Circular buffer reveló la presencia de 123 subpoblaciones de P. macroloba distribuidas en un radio de 5 699 943 km² a lo largo de la región neotropical. Conclusiones: Gran parte de las estructuras morfológicas de P. macroloba son respuestas adaptativas y evolutivas al ambiente periódicamente inundado del estuario del Amazonas, lo que demuestra que estos ambientes actúan como filtro ambiental seleccionado las especies mejor adaptadas al medio. Su amplia área geográfica denota la plasticidad de adaptarse a diferentes ambientes, lo que puede justificar su monodominancia en algunas regiones.

Highly efficient production of diverse rare ginsenosides using combinatorial biotechnology.

The rare ginsenosides are recognized as the functionalized molecules after the oral administration of Panax ginseng and its products. The sources of rare ginsenosides are extremely limited because of low ginsenoside contents in wild plants, hindering their application in functional foods and drugs. We developed an effective combinatorial biotechnology approach including tissue culture, immobilization, and hydrolyzation methods. Rh2 and nine other rare ginsenosides were produced by methyl jasmonate-induced culture of adventitious roots in a 10 L bioreactor associated with enzymatic hydrolysis using six ß-glycosidases and their combination with yields ranging from 5.54 to 32.66 mg L-1 . The yield of Rh2 was furthermore increased by 7% by using immobilized BglPm and Bgp1 in optimized pH and temperature conditions, with the highest yield reaching 51.17 mg L-1 (17.06% of protopanaxadiol-type ginsenosides mixture). Our combinatorial biotechnology method provides a highly efficient approach to acquiring diverse rare ginsenosides, replacing direct extraction from Panax plants, and can also be used to supplement yeast cell factories.

Effect of temperature on morphology, ginsenosides biosynthesis, functional genes, and transcriptional factors expression in Panax ginseng adventitious roots.

This study researched the effect of temperature on growth and ginsenosides accumulation in adventitious root cultures of Panax ginseng. Results showed that the ginseng adventitious roots growth and differentiation ability could be affected faced with different incubation temperatures (15, 20, 25, and 30°C for 35 days). Besides, the research also demonstrated that low-temperature stimulation could promote the accumulation of ginsenosides and the content of total ginsenosides increased by 2.53 times at 10°C-7d (10°C for 7 days and then transferred to 25°C for 28 days) compared with that at 25°C. Moreover, the transcriptional levels of functional genes and PgWRKYs were analyzed by this study and the correlation analysis showed that GPS, SS, CYP716A47, CYP716A53v2, UGT74AE2, UGT94Q2, PgWRKY1, PgWRKY3, and PgWRKY8 were significantly correlated with total ginsenosides content. Furthermore, HPLC-ESI-MSn analyzed that Malonyl-Rb1 only existed in 10°C-7d group. PRACTICAL APPLICATIONS: The survey showed that after a certain time of stimulating P. ginseng adventitious roots at low temperature, the accumulation of ginsenosides could be enhanced as their expression of related genes were regulated. It provides a theoretical foundation for the mass production of ginsenosides by controlling the temperature conditions of P. ginseng adventitious roots.

Production of biomass and medicinal metabolites through adventitious roots in Ajuga bracteosa under different spectral lights.

Ajuga bracteosa an important medicinal herb, is getting endangered worldwide due to destructive harvesting by pharmaceutical industries in its different habitats. It is in dire need for protection and demands conservation and sustainable utilization. In the present study, effects of α-naphthalene acetic acid (NAA) under different spectral lights were estimated on the growth, secondary metabolism and biosynthesis of phenolic acids in adventitious roots (AR) cultures of A. bracteosa. Among the different spectral lights, highest AR induction frequency (88%) and formation of biomass (72 g/L FW and 22 g/L DW) were recorded in explants incubated in the presence of 1.5 mg/L NAA under yellow light. Maximum production of poly phenols (TPC;44.2 mg) and flavonoids (TFC;2.51 mg) were recorded in the AR cultures grown in the presence of blue light. Further, highest total protein content of (401.6 µg) was detected in the AR in response to normal white light. Blue spectral light induced maximum superoxide dismutase (SOD; 2.5 nM) and peroxidase activity (POD;0.85 nM) respectively, in AR cultures. Compared with other monochromatic lights, red light significantly enhanced the antioxidant potential of the AR cultures. Analysis through High performance liquid chromatography (HPLC-DAD) revealed significant variations in the levels of important phenolic acids such as gallic acid, catechin, rutin, caffeic acid, myricetin and apigenin in the AR samples treated with the lights of different spectra.

Advances in Bioculture Technology of Bupleuri Radix and Biosynthesis Pathways of Saikosaponins / 中国实验方剂学杂志

Synthetic biology is an emerging discipline that analyzes the biosynthesis pathways of active constituents in traditional Chinese medicine and explores genes involved in biosynthesis. Bupleuri Radix is one of the most commonly used Chinese medicinal materials with remarkable medicinal value, its index component is saikosaponins, which has significant anti-inflammatory, anti-viral and anti-tumor activities. However, the current wild resources of Bupleuri Radix have been destroyed, and there were some problems in the process of artificial cultivation. The application of biological culture technology and synthetic biology can expand the sources of saikosaponins and protect resources of Bupleuri Radix. The culture conditions of different plants can be followed without a fixed pattern, and the biosynthetic pathways of different medicinal active ingredients are also inconsistent. At present, there is no review report on the culture technology of Bupleuri Radix and the research on the biosynthesis pathway of saikosaponins. This paper introduces the research progress of biological culture techniques, such as callus culture, adventitious root culture, hairy root culture and suspension cell culture used in synthetic biology, and the biosynthesis pathway of saikosaponins and its key enzyme functional genes. It is suggested to optimize the biological culture technology of Bupleuri Radix by referring to the tissue culture technology of other traditional root medicinal materials, so as to provide a reference for the in-depth study on the biosynthesis pathway and metabolic regulation of saikosaponins.

Quality, safety and efficacy profiling of ginseng adventitious roots produced in vitro.

Ginseng (Panax ginseng C. A. Meyer, Family Araliaceae) is one of the major medicinal and nutraceutical plants, which is native to oriental region. It is used worldwide as a popular herbal medicine because of its pharmacological effects like anti-oxidative, anti aging, anti-cancer, adaptogenic, and other health-improving activities. Chief components of ginseng identified till date are ginsenosides, a group of saponins with triterpenoid structure. Ginseng is cultivated under controlled conditions, and for harvesting of fully grown roots of the plant, the cultivation takes long duration of about 5-7 years and cultivated ginseng roots are inferior in quality and ginsenoside content. Wild Mountain ginseng is superior in quality and ginsenoside content but is scarce in nature. Therefore, for obtaining the useful compounds of this plant at commercial scale, cell and organ cultures especially adventitious roots have been established by using superior clones of wild mountain ginseng, ginseng biomass is produced by applying large scale bioreactors. In this paper, an effort has been made to shed light on the scientific literature and to decipher the evidences for quality, safety, and efficacy of ginseng adventitious roots produced from in vitro cultures.

Anti-cancer labdane diterpenoids from adventitious roots of Andrographis paniculata: augmentation of production prospect endowed with pathway gene expression.

Andrographolide (AD) is the time-honoured pharmacologically active constituent of the traditionally renowned medicinal plant-Andrographis paniculata. Advancements in the target-oriented drug discovery process have further unravelled the immense therapeutic credibility of another unique molecule-neoandrographolide (NAD). The escalated market demand of these anti-cancer diterpenes is increasingly facing unrelenting hurdles of demand and supply disparity, attributable to their limited yield. Callus and adventitious root cultures were generated to explore their biosynthetic potentials which first time revealed NAD production along with AD. Optimization of the types and concentrations of auxins along with media form and cultivation time led to the successful tuning towards establishing adventitious roots as a superior production alternative for both AD/NAD. Supplementation of IBA to the NAA + Kn-containing MS medium boosted the overall growth and AD/NAD synthesis in the adventitious roots. Compared to control leaves, the adventitious root exhibited about 2.61- and 8.8-fold higher contents of AD and NAD, respectively. The qRT-PCR involving nine key pathway genes was studied, which revealed upregulation of GGPS1 and HMGR1/2 genes and downregulation of DXS1/2 and HDR1/2 genes in the adventitious root as compared to that in the control leaves. Such observations highlight that in vitro cultures can serve as efficient production alternatives for AD/NAD as the cytosolic genes (HMGR1/2 of MVA pathway) are competent enough to take over from the plastidial genes (DXS1/2 and HDR1/2 of MEP pathway), provided the accredited first branch-point regulatory gene (GGPS) expression and the culture requirements are optimally fulfilled.

A disturbed auxin signaling affects adventitious root outgrowth in Solanum dulcamara under complete submergence.

Flooding negatively affects the growth and even survival of most terrestrial plants. Upon flooding, the excess water quickly decreases the gas exchange between atmosphere and the submerged plant tissues, which leads to oxygen deficiency resulting in a plant cell energy crisis, and eventually plant death. Solanum dulcamara survives flooding by producing aerenchymatous adventitious roots (ARs) from pre-formed primordia on the stem, which replace the original flood-sensitive root system. However, we found that under complete submergence, AR outgrowth was impaired in S. dulcamara. In the present work, we tried to elucidate the mechanisms behind this phenomenon in particular the involvement of the phytohormones auxin, abscisic acid and jasmonic acid. Abscisic acid (ABA) is a negative regulator of AR outgrowth, but surprisingly the ABA content and signaling were decreased to a similar extent under both partial and complete submergence, suggesting that ABA might not be responsible for the difference in AR outgrowth. Auxin, which is necessary for AR outgrowth, was at similar concentrations in either partially or completely submerged primordia, but complete submergence resulted in a decrease of auxin signaling in the primordia. Application of 1-naphthaleneacetic acid (NAA) to completely submerged plants restored AR outgrowth, implying that auxin response in the rooting tissues of completely submerged plants was reduced. Furthermore, jasmonic acid (JA) concentrations did not differ between partial and complete submergence. To conclude, a disruption in the auxin signaling within S. dulcamara AR primordia may result in the abortion of AR outgrowth under complete submergence.

Biotic elicitation of ginsenoside metabolism of mutant adventitious root culture in Panax ginseng.

Biotic elicitation is an important biotechnological strategy for triggering the accumulation of secondary metabolites in adventitious root cultures. These biotic elicitors can be obtained from safe, economically important strains of bacteria found in the rhizosphere and fermented foods. Here, we assayed the effects of filtered cultures of five nitrogen-fixing bacteria and four types of fermentation bacteria on mutant adventitious Panax ginseng root cultures induced in a previous study by colchicine treatment. The biomass, pH, and electrical conductivity (EC) of the culture medium were altered at 5 days after treatment with bacteria. The saponin content was highest in root cultures treated with Mesorhizobium amorphae (GS3037), with a concentration of 105.58 mg g-1 dry weight saponin present in these cultures versus 74.48 mg g-1 dry weight in untreated root cultures. The accumulation of the ginsenosides Rb2 and Rb3 dramatically increased (19.4- and 4.4-fold, and 18.8- and 4.8-fold) 5 days after treatment with M. amorphae (GS3037) and Mesorhizobium amorphae (GS336), respectively. Compound K production increased 1.7-fold after treatment with M. amorphae (GS3037) compared with untreated root cultures. These results suggest that treating mutant adventitious root cultures with biotic elicitors represents an effective strategy for increasing ginsenoside production in Panax ginseng.

Impacts of methyl jasmonate and phenyl acetic acid on biomass accumulation and antioxidant potential in adventitious roots of Ajuga bracteosa Wall ex Benth., a high valued endangered medicinal plant.

Ajuga bracteosa is a medicinally important plant globally used in the folk medicine against many serious ailments. In the present study, effects of two significant elicitors, methyl jasmonate (Me-J) and phenyl acetic acid (PAA) were studied on growth parameters, secondary metabolites production, and antioxidant potential in adventitious root suspension cultures of A. bracteosa. The results showed a substantial increase in biomass accumulation, exhibiting longer log phases of cultures growth in response to elicitor treatments, in comparison to control. Maximum dry biomass formation (8.88 DW g/L) was recorded on 32nd day in log phase of culture when  0.6 mg/L Me-J was applied; however, PAA at 1.2 mg/L produced maximum biomass (8.24 DW g/L) on day 40 of culture.  Furthermore, we observed the elicitors-induced enhancement in phenolic content (total phenolic content), flavonoid content (total flavonoid content) and antioxidant activity (free radical scavenging activity) in root suspension cultures of A. bracteosa. Application of 0.6 mg/L and 1.2 mg/L of Me-J, root cultures accumulated higher TPC levels (3.6 mg GAE/g DW) and (3.7 mg GAE/g DW) in the log phase and stationary phase, respectively, while 2.5 mg/L Me-J produced lower levels (1.4 mg GAE/g DW) in stationary phase of growth stages. Moreover, TFC and FRSA values were found in correspondence to TPC values in the respective growth phases at the similar elicitor treatment. Thus, a feasible protocol for establishment of adventitious roots in A. bracteosa was developed and enhancement in biomass and metabolite content in adventitious root was promoted through elicitation.

Microbial transformation of ginsenosides extracted from Panax ginseng adventitious roots in an airlift bioreactor

Background: Ginsenoside is the most important secondary metabolite in ginseng. Natural sources of wild ginseng have been overexploited. Although root culture can reduce the length of the growth cycle of ginseng, the number of species of ginsenosides is reduced and their contents are lower in the adventitious roots of ginseng than in the roots of ginseng cultivated in the field. Results: In this study, 147 strains of ß-glucosidase-producing microorganisms were isolated from soil. Of these, strain K35 showed excellent activity for converting major ginsenosides into rare ginsenosides, and a NCBI BLAST of its 16S rDNA gene sequence showed that it was most closely related to Penicillium sp. (HQ608083.1). Strain K35 was used to ferment the adventitious root extract, and the fermentation products were analyzed by high-performance liquid chromatography. The results showed that the content of the rare ginsenoside CK was 0.253 mg mL-1 under the optimal converting conditions of 9 d of fermentation at pH 7.0 in LL medium, which was significantly higher than that in the adventitious roots of ginseng. Conclusion: These findings may not only solve the problem of low productivity of metabolite in ginseng root culture but may also result in the development of a new valuable method of manufacturing ginsenoside CK.

Panax ginseng Adventitious Root Suspension Culture: Protocol for Biomass Production and Analysis of Ginsenosides by High Pressure Liquid Chromatography.

Panax ginseng C.A. Meyer (Korean ginseng) is a popular herbal medicine. It has been used in Chinese and Oriental medicines since thousands of years. Ginseng products are generally used as a tonic and an adaptogen to resist the adverse influence of a wide range of physical, chemical and biological factors, and to restore homeostasis. Ginsenosides or ginseng saponins are the principal active ingredients of ginseng. Since ginseng cultivation process is very slow and needs specific environment for field cultivation, cell and tissue cultures are sought as alternatives for the production of ginseng biomass and bioactive compounds. In this chapter, we focus on methods of induction of adventitious roots from ginseng roots, establishment of adventitious root suspension cultures using bioreactors, procedures for processing of adventitious roots, and analysis of ginsenosides by high pressure liquid chromatography.

Life cycle stage and water depth affect flooding-induced adventitious root formation in the terrestrial species Solanum dulcamara.

BACKGROUND AND AIMS: Flooding can occur at any stage of the life cycle of a plant, but often adaptive responses of plants are only studied at a single developmental stage. It may be anticipated that juvenile plants may respond differently from mature plants, as the amount of stored resources may differ and morphological changes can be constrained. Moreover, different water depths may require different strategies to cope with the flooding stress, the expression of which may also depend on developmental stage. This study investigated whether flooding-induced adventitious root formation and plant growth were affected by flooding depth in Solanum dulcamara plants at different developmental stages. METHODS: Juvenile plants without pre-formed adventitious root primordia and mature plants with primordia were subjected to shallow flooding or deep flooding for 5 weeks. Plant growth and the timing of adventitious root formation were monitored during the flooding treatments. KEY RESULTS: Adventitious root formation in response to shallow flooding was significantly constrained in juvenile S. dulcamara plants compared with mature plants, and was delayed by deep flooding compared with shallow flooding. Complete submergence suppressed adventitious root formation until up to 2 weeks after shoots restored contact with the atmosphere. Independent of developmental stage, a strong positive correlation was found between adventitious root formation and total biomass accumulation during shallow flooding. CONCLUSIONS: The potential to deploy an escape strategy (i.e. adventitious root formation) may change throughout a plant's life cycle, and is largely dependent on flooding depth. Adaptive responses at a given stage of the life cycle thus do not necessarily predict how the plant responds to flooding in another growth stage. As variation in adventitious root formation also correlates with finally attained biomass, this variation may form the basis for variation in resistance to shallow flooding among plants.

Enhancing phosphorus and zinc acquisition efficiency in rice: a critical review of root traits and their potential utility in rice breeding.

BACKGROUND: Rice is the world's most important cereal crop and phosphorus (P) and zinc (Zn) deficiency are major constraints to its production. Where fertilizer is applied to overcome these nutritional constraints it comes at substantial cost to farmers and the efficiency of fertilizer use is low. Breeding crops that are efficient at acquiring P and Zn from native soil reserves or fertilizer sources has been advocated as a cost-effective solution, but would benefit from knowledge of genes and mechanisms that confer enhanced uptake of these nutrients by roots. SCOPE: This review discusses root traits that have been linked to P and Zn uptake in rice, including traits that increase mobilization of P/Zn from soils, increase the volume of soil explored by roots or root surface area to recapture solubilized nutrients, enhance the rate of P/Zn uptake across the root membrane, and whole-plant traits that affect root growth and nutrient capture. In particular, this review focuses on the potential for these traits to be exploited through breeding programmes to produce nutrient-efficient crop cultivars. CONCLUSIONS: Few root traits have so far been used successfully in plant breeding for enhanced P and Zn uptake in rice or any other crop. Insufficient genotypic variation for traits or the failure to enhance nutrient uptake under realistic field conditions are likely reasons for the limited success. More emphasis is needed on field studies in mapping populations or association panels to identify those traits and underlying genes that are able to enhance nutrient acquisition beyond the level already present in most cultivars.