Enhancement of Macarpine Production in Eschscholzia Californica Suspension Cultures under Salicylic Acid Elicitation and Precursor Supplementation.

Macarpine is a minor benzophenanthridine alkaloid with interesting biological activities, which is produced in only a few species of the Papaveraceae family, including Eschscholzia californica. Our present study was focused on the enhancement of macarpine production in E. californica suspension cultures using three elicitation models: salicylic acid (SA) (4; 6; 8 mg/L) elicitation, and simultaneous or sequential combinations of SA and L-tyrosine (1 mmol/L). Sanguinarine production was assessed along with macarpine formation in elicited suspension cultures. Alkaloid production was evaluated after 24, 48 and 72 h of elicitation. Among the tested elicitation models, the SA (4 mg/L), supported by L-tyrosine, stimulated sanguinarine and macarpine production the most efficiently. While sequential treatment led to a peak accumulation of sanguinarine at 24 h and macarpine at 48 h, simultaneous treatment resulted in maximum sanguinarine accumulation at 48 h and macarpine at 72 h. The effect of SA elicitation and precursor supplementation was evaluated also based on the gene expression of 4'-OMT, CYP719A2, and CYP719A3. The gene expression of investigated enzymes was increased at all used elicitation models and their changes correlated with sanguinarine but not macarpine accumulation.

A Fluorescence Anisotropy-Based Comprehensive Method for the In Vitro Screening of COI1-JAZs Agonists and Antagonists.

The phytohormone (+)-7-iso-jasmonoyl-L-isoleucine (JA-Ile) causes protein-protein interactions (PPI) between F-box Protein CORONATINE INSENSITIVE 1 (COI1) and JASMONATE ZIM DOMAIN (JAZ) transcriptional repressor. A total of 13 JAZ subtypes are encoded in the genome of Arabidopsis thaliana; however, their genetic redundancy obfuscates the individual function of each JAZ. One approach to decipher this redundant signaling network is chemical genetics, using small molecules specific to individual JAZ subtype, for which a reliable and high-throughput screening system of the ligands for all combinations of COI1-JAZs would be indispensable. In this chapter, we describe a fluorescence anisotropy-based quantitative screening system for the ligands of COI1-JAZ co-receptors. Our method is applicable to agonists and antagonists of the COI1-JAZs.

Phenotypic and biochemical alterations in relation to MT2 gene expression in Plantago ovata Forsk under zinc stress.

Plantago ovata Forsk is an annual herb with immense medicinal importance, the seed and husk of which is used in the treatment of chronic constipation, irritable bowel syndrome, diarrhea since ancient times. Zinc, an essential metal, is required by plants as they form important components of zinc finger proteins and also aid in synthesis of photosynthetic pigments such as chlorophyll. However, in excess amount Zn causes chlorosis of leaf and shoot tissues and generate reactive oxygen species. The present study is aimed at investigating the changes in expression levels of MT2 gene in Plantago ovata under zinc stress. Data show up to 1.66 fold increase in expression of PoMT2 in 1000 µM ZnSO4·7H2O treated sample. Our study also describes alteration of MT2 gene expressions in Plantago ovata as observed through Real time PCR (qPCR) done by [Formula: see text] method. In this study we have observed an upregulation (or induction) in the PoMT2 gene expression level in 500 and 800 µM ZnSO4·7H2O treated samples but found saturation on further increasing the dose to 1000 µM of ZnSO4·7H2O. Determination of the phenotypic and biochemical changes in Plantago ovata due to exposure to zinc stress of concentrations 500, 800 and 1000 µM revealed oxidative stress. The enhanced expression of MT2 gene in Plantago ovata has a correlation with the increased total antioxidant activity and increased DPPH radical scavenging activity.

Elicitation and treatment with precursors of phenolics synthesis improve low-molecular antioxidants and antioxidant capacity of buckwheat sprouts.

BACKGROUND: Recently, an increase of interest in the modification of food products on each step of production (breeding, production technology, storage condition) is observed. Nutritional properties as well as level and activity of bioactive compounds in plant-origin food may be modified using a range of technological and biotechnological practices and elicitation should be mentioned between them. METHODS: Elicitation with willow bark infusion supported by feeding with the phenylpropanoid pathway precursors were used for improving the quality of buckwheat sprouts. Special emphasis has been placed on the metabolomic and biochemical changes and the mechanism of overproduction of low-molecular antioxidants. RESULTS: The accumulation of phenolics is caused by stimulation of two main enzymes the phenylpropanoid pathway (tyrosine ammonia-lyase and phenylalanine ammonia-lyase). Tyrosine ammonia-lyase activities were effectively induced by feeding with tyrosine (about four times that of the control), whereas phenylalanine ammonia-lyase activity was the highest in the elicited control sprouts and those fed with shikimic acid (an increase by 60% compared to the control). Shikimic acid feeding (both elicited and non-elicited sprouts) effectively improved the total phenolics (by about 10% and 20%, respectively), condensed tannins (by about 30% and 28%, respectively), and flavonoids (by about 46% and 70%, respectively). Significant increase of vitexin, rutin, chlorogenic acid and isoorientin contents was also observed. The treatments increased the ascorbic acid content, too. Total antioxidant capacity of sprouts was most effectively increased by feeding with shikimic acid and further elicitation. CONCLUSIONS: The studies transfer biotechnology commonly used for the induction of overproduction of secondary metabolites in plant cell line systems to low-processed food production. The obtained results could be used for better understanding of the effect of elicitation and precursor feeding on antioxidants production and contribute to improving the buckwheat sprouts quality.

Key role of Fe(2+) in epithiospecifier protein activity.

The chemical nature of the hydrolysis products from the glucosinolate-myrosinase system depends on the presence or absence of supplementary proteins such as epithiospecifier proteins (ESPs). ESPs promote the formation of epithionitriles from terminal alkenyl glucosinolates and, as recent evidence suggests, simple nitriles at the expense of isothiocyanates. From a human health perspective isothiocyanates are the most important because they are major inducers of carcinogen-detoxifying enzymes. Fe(2+) is an essential factor in ESP activity, although several recent studies have highlighted discrepancies in the understanding of the ESP-iron interaction. To investigate further the role iron species play in regulating ESP activity, four ESP-containing seedpowders were analyzed for ESP and myrosinase activities, endogenous iron content, and glucosinolate degradation products after the addition of iron species, specific chelators, and reducing agents. For the first time this paper shows the effect of these additions on the hydrolysis of individual glucosinolates that constitute the total pool. Aged seeds and 3-day seedlings were also tested to investigate the effects of seed storage and early plant development on iron levels and ESP activity. The four ESP-containing plant systems tested gave two distinctive responses, thus providing strong evidence that ESPs vary markedly in their Fe(2+) requirement for activity. The results also indicated that reduction of ferric to ferrous iron drives variations in ESP activity during early plant development. The reverse oxidation reaction provided a convincing explanation for the loss of ESP activity during seed storage. Aged seeds produced seedlings with substantially lower ESP activity, and there was a concomitant loss in germination rate. It was concluded that manipulation of endogenous iron levels of ESP-containing plants could increase the conversion of glucosinolates to isothiocyanates and enhance potential health benefits.