Induction and Activation of Plant Secondary Metabolism by External Stimuli
نویسنده
چکیده
It is widely recognized that plant cells are potentially rich sources of commercially important secondary metabolites. The production of secondary metabolites in plants would be mainly controlled by transcriptional activities of a series of genes which encode the specific enzymes in the biosynthetic pathway of desired products. It is likely, however, that the catalytic activities of these enzymes are sometimes repressed or maintained at very low levels, and the mechanism involved in 'switch on' of the genetic information on secondary metabolism in plants is, at present, only very poorly understood. The response of plant cells to ‘elicitors’ was first studied from the phytopathological point of view to elucidate the regulation mechanism of phytoalexin production. However, extensive investigations clearly indicated (Zhao et al., 2005) that the treatment of plant cells with elicitor-active substances sometimes results in a rapid accumulation of secondary products other than defense-related compounds. Recently, it has been also demonstrated (Gundlach et al., 1992) that the function of elicitors can be sometimes replaced by jasmonic acid and its methyl ester, methyl jasmonate, the plant specific messenger molecules derived from arachidonic acid. Effective application of elicitors and/or jasmonates to the production of useful metabolites in plant cells requires the elucidation of the basic biochemical mechanisms by which these external stimuli regulate the genetic information involved in the biosynthesis of the natural products. Several questions are raised against the external stimuli-induced activation of the secondary metabolites production in plants. 1) How are the external signals recognized by plant cells? 2) How are the signals transduced in the cells? 3) How do the signals alter the expression of biosynthesis-related genes? 4) How are the enzyme activities controlled to produce secondary metabolites? Effective use of elicitors and jasmonates in producing useful metabolites in plants requires the elucidation of these biochemical mechanisms by which these stimuli regulate the genetic information. To answer these questions, we first attempted to elucidate the possible participation of second messengers in the secondary metabolism activation stimulated by exogenous signals.
منابع مشابه
Glutathione S- transferases and their function as a protein superfamily in plants
Glutathione s transferase (GST) is one of the largest protein and multigene families present in all plant species and other living organisms. For these proteins, which are highly inducible to stress and internal and external stimuli, several functions in plants have been identified, including implication in secondary metabolism, growth and development, detoxification of herbicides, coping with...
متن کاملA Review on Experimental Assessments of Pain Threshold in Healthy Human Subjects
A B S T R A C T There are three types of nerve fibers that are involved in the transmission of pain stimuli: C fibers (slower fibers) for thermal, mechanical and chemical stimuli, A-delta fibers for thermal or mechanical stimuli and A-beta fibers for touch stimuli. Clinically, this is crucial in making an accurate assessment of the pain level experienced by a suffering patient, in indicating th...
متن کاملSeed priming with Electromagnetic Field Improved Growth, Nutrition, And Metabolism of Salvia nemorosa L.
In this study, the efficiencies of seed priming with electromagnetic field (0, 2, 4, and 6 mT; 30 minutes daily for 3 days) were investigated in Salvia nemorosa. The exposure to electromagnetic filed led to significant increases in biomass accumulation (mean=53.6 %). Electromagnetic filed treatments significantly increased K, Ca, Mg, and Fe contents in leaves by mean 39.5 %. The electromagnetic...
متن کاملImmunostimulatory effect of the aqueous leaf extract of Phyllanthus niruri on the specific and nonspecific immune responses of Oreochromis mossambicus Peters
Plant derived immunostimulants are a promising alternative to chemotherapeutics and also perhaps vaccines. In the present study, we examined the immunostimulating properties of aqueous leaf extract of Phyllanthus niruri, an Indian traditional medicinal herb, on neutrophil activation and antibody response of Oreochromis mossambicus (Peters). Serial ten-fold diluted doses of P. niruri ranging fro...
متن کاملOptimization of callus induction of Zataria multiflora under the effect of different plant growth regulators and explant source
Background and objectives: The Lamiaceae family is rich in favorable secondary metabolites which have different medicinal properties and also use in food, cosmetic and sanitary industry. Zataria multiflora Boiss. is an aromatic and bushy plant containing specific pharmaceutical components which is only distributed in certain regions of Iran. Tissue culture tec...
متن کامل