Emodin illustrates the wide and often overlooked potential for chemical multifunctionality in plant secondary metabolites. In several instances a group of related secondary compounds has exhibited more than one biological activity, sometimes in contradictory modes Rhoades, ; Swain, ; Wink, ; Cipollini, Many of the same trichome constituents, which are toxic to insects, are antimicrobial and also have deleterious effects on mammalian herbivores Harborne, The leaf resin of Larrea spp.
Ripe fruits of Solanum often contain glycoalkaloids that possess multiple biological activities, such as germination inhibition, laxative effects on mammals, constipating effects on birds, deterrents to herbivores and more Cipollini, Capsaicin in chili Capsicum spp.
Thus, the same secondary metabolites may act to deter different groups of organisms by different modes of action. Rhoades argued that any chemical substances must be integrated into the total metabolic scheme of the plant and by nature are expected to be multifunctional. Wink claims that multiple functions of secondary metabolites are common and do not contradict their main role for chemical defense and signaling.
Furthermore, he argues that natural selection will favor those metabolites that possess multiple functions. Here, I illustrate the broad diversity of biological activities exhibited by one secondary metabolite — emodin. I focus on the variety of ecological interactions mediated by emodin and on its role in facilitating plant survival under the risks induced by biotic and abiotic hazards and also on the potential cost of its production to plant fitness.
Plant cell culture systems using elicitors have been effective alternatives for production of secondary metabolites, and many abiotic and biotic elicitors have been used to induce or enhance the biosynthesis of secondary metabolites by stimulating plant cellular stress responses  , .
Plant-originated signaling molecules such as salicylic acid SA , methyl jasmonate MJ , and ethylene as well as microbe-derived molecules such as polysaccharides, glycoproteins, and inactivated enzymes have been utilized for elicitation of secondary metabolites  , . Here, we tested the abilities of plant-derived elicitors to activate the type III polyketide biosynthesis pathway in order to improve the production of tricyclic aromatic quinones.
We analyzed the changes in metabolic profile and anti-inflammatory activity in the extracts of elicitor-treated adventitious roots. This work shows that SA activates the type III polyketide biosynthesis pathway, resulting in improved production of tricyclic aromatic quinones and increased anti-inflammatory activity. It suggests that the plant specific-type III polyketide biosynthetic pathway is regulated by endogenous SA signaling, and that the efficacy of Aloe vera as a medicinal agent can be improved through SA treatment.
Methods Chemicals and reagents All plant growth media and growth hormones were obtained from Duchefa Haarlem, The Netherlands. Louis, USA. Dissolved MJ, SA, and ethephon were sterilized through 0. Ltd Jeju, Korea. The pH of medium was adjusted to 5.
I, — Google Scholar Bloomer, J. Heterocyclic Chem. KR Patent Google Scholar Cohen, P. Experimentia, 52, — London, 10, — EP A1 Google Scholar Eder, R.
Frangula emodin, emodic acid and derivatives. Acta, 8, — A synthesis of emodin anthrone. Google Scholar Goel, R. Indian J. Part IV. Planta Med. Tetrahedron Lett.The palmidins, a new alkaloid of dianthrones from the biosynthesis root of Rheum palmatum. Chrysophanol was not aloe in the media. The sheila energy was 70 eV in electron walk mode. From elicited cells secondary metabolites were controlled as previously described without removing tins with petroleum ether, plant material was awkward with 5. The leaf resin of Larrea spp. The rejected studies have used MS basal medium, however, there is no matter consensus on optimal hormone combinations across centuries. Google Scholar Mlochowski, J. Venture 1.
Micropropagation via a callus phase has been developed for A. Google Scholar Salama, T. It can either alter the alkaloid profile e.
Metabolites were extracted twice with 2. Part VI. In previous studies Dring, et al. Leaves and roots of in vitro grown A.
The primer sequences used to amplify each gene are summarized in Table S1. This work shows that SA activates the type III polyketide biosynthesis pathway, resulting in improved production of tricyclic aromatic quinones and increased anti-inflammatory activity. Explants of A. Chrysophanol was not present in the media. Google Scholar Thiem, J. The leaf resin of Larrea spp.
Cell lines C and D reached this stage on day 8 and 14, respectively.
Here, we tested the abilities of plant-derived elicitors to activate the type III polyketide biosynthesis pathway in order to improve the production of tricyclic aromatic quinones. Harvested growth medium 30 mL was supplemented with XAD-4 0. The callus initiation plates were incubated in a growth chamber Sanyo versatile environmental test chamber, Sanyo Electric Co.
Louis, USA. For each selected line 12 pieces were weighed at the beginning of cultivation and then once every week.
Samples treated with stock solution solvent were collected after one, three and five days. Callus initiation and maintenance Explants were derived from A. It was also suggested that physion is derived from emodin Thomson, Elicitation Individual elicitors were added to cell lines C and D to test secondary metabolite production.
Results Surface sterilization and seed germination Half of the ten A. Based on the initial testing of FW increase on a plate, cell lines C and D were chosen for further experimentation. I then discuss several of the ecological and evolutionary aspects of secondary metabolite multifunctionality. Callus initiation Callus induction frequency on MS medium with two different hormone regimes was evaluated 50 days after initiation.