[Secondary metabolic responses to treatment of 2-aminoindan-2-phosphonic acid in cell lines from Arnebia euchroma].

The accumulation of rosmarinic acid, acetylshikonin, deoxyshikonin, ß, ß'-dimethylacrylshikonin and isovalerylshikonin was investigated in cell suspension cultures of Arnebia euchroma (Royle) Johnst under the influence of 2-aminoindan-2-phosphonic acid (AIP), an inhibitor of phenylalanine ammonia lyase (PAL), and of the effector methyl jasmonate (MeJA). The results showed that methyl jasmonate promoted the accumulation of rosmarinic acid and shikonin derivatives. Conversely, 2-aminoindan-2-phosphonic acid suppressed the formation of rosmarinic acid, which indicated that AIP, indeed, was able to inhibit the phenylpropanoid pathway in A. euchroma. Meanwhile, the content of total shinkonins and other four kinds of shikonin derivatives, though varied in degrees, was also inhibited. And the inhibition was dose-dependent and time-dependent. Acetylshikonin responsed most rapidly to the treatment of AIP, the content reduced after 24 h of treatment and decreased to only half of those untreated control 48 h after teratment. ß, ß'-Dimethylacrylshikonin, difffer from acetylshikonin, responded much slowly to the treatment, inhibition could only be observed 96 h later. These suggest that phenylpropanoid pathway plays an important role in the shikoninsbiosynthesis, and this study provides a reference for the further research in metabolic regulation of producing shikonins by cell culture technology and biosynthesis pathways of shikonin derivatives. Still, shikonins biosynthesis pathways is complicated, the exact dose- and time-effect relationship of AIP and interaction between AIP and other effectors like MeJA need further research.

[Growth and accumulation of shikonin compounds of two kinds of cells in suspension culture of Arnebia euchroma].

Via studying the phenotype, growth curve and secondary metabolites of two kinds of suspension culture cell of Arnebia euchroma, the kinetics parameters of growth and accumulation of shikonin compounds in cell suspension culture of A. euchroma was obtained through simulating and modeling. This Study found that the red high-yielding one was a fine cell line for producing shikonin compounds, and the white low-yielding one may be a mutant. The first-order and second-order derivative of the fitting function were obtained by fitting the Logistic model of growth curve to get the growth rate and growth acceleration curve of the suspended cells. It is found that the best period to subculture was the 15th day cultured in fresh medium, and the best period of the induction process was the 13th-14th day. When compared the growth rate of the red line and the shikonin compounds accumulation curve, it is found that the rapid growth of the biomass of cells was not conducive to the synthesis and accumulation of shikonin compounds.

Distinct cell-specific expression of homospermidine synthase involved in pyrrolizidine alkaloid biosynthesis in three species of the boraginales.

Homospermidine synthase (HSS) is the first specific enzyme in pyrrolizidine alkaloid (PA) biosynthesis, a pathway involved in the plant's chemical defense. HSS has been shown to be recruited repeatedly by duplication of a gene involved in primary metabolism. Within the lineage of the Boraginales, only one gene duplication event gave rise to HSS. Here, we demonstrate that the tissue-specific expression of HSS in three boraginaceous species, Heliotropium indicum, Symphytum officinale, and Cynoglossum officinale, is unique with respect to plant organ, tissue, and cell type. Within H. indicum, HSS is expressed exclusively in nonspecialized cells of the lower epidermis of young leaves and shoots. In S. officinale, HSS expression has been detected in the cells of the root endodermis and in leaves directly underneath developing inflorescences. In young roots of C. officinale, HSS is detected only in cells of the endodermis, but in a later developmental stage, additionally in the pericycle. The individual expression patterns are compared with those within the Senecioneae lineage (Asteraceae), where HSS expression is reproducibly found in specific cells of the endodermis and the adjacent cortex parenchyma of the roots. The individual expression patterns within the Boraginales species are discussed as being a requirement for the successful recruitment of HSS after gene duplication. The diversity of HSS expression within this lineage adds a further facet to the already diverse patterns of expression that have been observed for HSS in other PA-producing plant lineages, making this PA-specific enzyme one of the most diverse expressed proteins described in the literature.

Physico-chemical factors influencing the shikonin derivatives production in cell suspension cultures of Arnebia euchroma (Royle) Johnston, a medicinally important plant species.

Cell suspension cultures of Arnebia euchroma were raised from in vitro leaf-derived friable callus on liquid MS [Murashige and Skoog] medium supplemented with BAP (6-benzylaminopurine) (10.0 µM) and IBA (indole-3-butyric acid) (5.0 µM). A two-stage culture system was employed using growth and production medium for cell biomass and shikonin derivatives, respectively. Factors such as light, temperature, sucrose and pH (hydrogen ion concentration) were studied to observe their effect on the shikonin derivative production. Light conditions completely inhibited shikonin derivative production. Out of different temperature regimes tested, the highest yield (586.17 µg/g FW) was found at 25°C. Maximum production (656.14 µg/g FW) was observed in 6% sucrose. An alkaline pH (7.25-9.50) favoured shikonin derivative production. The results showed that physical and chemical factors greatly influence the production of shikonin derivatives in cell suspension cultures of A. euchroma. Therefore, by employing optimum culture conditions, it is possible to enhance the production of secondary compounds from the cells. The factors optimized for in vitro production of shikonin derivatives during the present study can successfully be employed for their large-scale production in bioreactors.

Expression analysis of light-regulated genes isolated from a full-length-enriched cDNA library of Onosma paniculatum cell cultures.

Shikonin and its derivatives are formed in large amounts in dark-cultured Onosma paniculatum cells. In order to isolate and identify the genes regulating shikonin biosynthesis, we constructed and characterized a full-length-enriched cDNA library of dark-cultured cells by using the SMART (Switching Mechanism At 5'-end of RNA Transcript) cDNA synthesis and LD-PCR (long-distance PCR) strategies. The titer of the primary cDNA library was 1.04 x 10(6)pfu/mL with a recombination rate of 99.60%. Most of the cDNA inserts ranged from 1.0 to 2.5 kb, and 78.33% of the 76 randomly selected clones contained full-length coding regions. Expression analysis of randomly selected genes by small scale microarray revealed that 23 genes were down-regulated, including 17 genes with known functions, 2 genes with putative functions, and 4 novel genes, and that 3 genes were up-regulated (two-fold) in cells cultured under white light as compared with those cultured in the dark. Interestingly, two of the down-regulated genes, encoding aci-reductone dioxygenase (ARD)-like protein and ethylene responsive factor (ERF), are involved in ethylene biosynthesis and signal transduction, implying that ethylene might play an important role as a signal molecule in light-regulated shikonin formation. These data contribute to a better understanding of light-involvement in regulating the formation of plant secondary metabolites.

High rabdosiin and rosmarinic acid production in Eritrichium sericeum callus cultures and the effect of the calli on masugi-nephritis in rats.

During an investigation of plant cell cultures that might be useful in the treatment of renal disorders, we established a vigorously-growing E-4 callus culture of Eritrichium sericeum that produced large amounts of caffeic acid metabolites, (-)-rabdosiin (1.8% dry wt) and rosmarinic acid (4.6% dry wt). Elicitation of the calli by methyl jasmonate induced a 38% increase in total polyphenol production. The most efficient method of eliciting (-)-rabdosiin biosynthesis was through the treatment of E-4 calli with cuprum glycerate, which induced an increase in (-)-rabdosiin production of as much as 4.1% dry wt. Oral administration of E-4 callus biomass (100 mg/kg/d for 30 d) to rats with induced Masugi-nephritis caused an increase in diuresis and lowered creatinine excretion and proteinuria levels as compared with Masugi-nephritis untreated rats. While all of the Masugi-nephritis untreated rats began to suffer, near a quarter of the E-4 treated rats remained in good health. This result indicates that the E-4 culture has the potential to alleviate the symptoms associated with nephritis.

Cell growth and shikonin production of Arnebia euchroma in a periodically submerged airlift bioreactor.

Arnebia euchroma was grown in a 2-l periodically submerged, airlift bioreactor (PSAB) in which the non-submerged (immobilization culture) and submerged (suspension culture) operations were controlled automatically. PSAB had advantages in improving cell growth, shikonin content, shikonin production and cell aggregation compared with suspension culture. Under the optimal submerged/non-submerged period of 10 min/15 h, the shikonin content (4.6%, w/w) and, cell dry mass (16.8 g/l) were 229 and 26% higher than those in suspension culture.