title: PAL inhibitor evokes different responses in two Hypericum species.
abstract: Accumulation of secondary metabolites (general phenols, naphthodianthrones and phloroglucinol hyperforin) in Hypericum perforatum and Hypericum canariense after application of the inhibitor (2-aminoindane-2-phosphonic acid, AIP) of the pivotal enzyme of general phenylpropanoid pathway (phenylalanine ammonia-lyase, PAL) was studied. Shoots of H. perforatum revealed more expressive growth depression, concomitantly with the inhibition of PAL activity (-60%) and decrease in soluble phenols and individual phenolic acids in response to AIP. Hypericins (hypericin, pseudohypericin and protohypericin) decreased while hyperforin increased in AIP-cultured H. perforatum. On the contrary, growth changes, decreases in soluble phenols and individual phenolic acids were less-visible in H. canariense. This was also reflected in restoration of PAL activity (+330%) and selected flavonoids even increased. Hypericins and hyperforin were present in several orders of magnitude lower amounts in comparison with H. perforatum. Increase in proline indicates potential compensatory antioxidative mechanism if phenols are depleted. Microscopy revealed also differences in secondary xylem formation and lignification between species after exposure to AIP.
authors.affiliation: Institute of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemědělská 1, 613 00 Brno, Czech Republic.
authors.forename: Bořivoj
authors.initials: B
authors.lastname: Klejdus
authors.forename: Jozef
authors.initials: J
authors.lastname: Kováčik
authors.forename: Petr
authors.initials: P
authors.lastname: Babula
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D000873:Anthracenes; D002726:Chlorogenic Acid / Q000378:metabolism; D020902:Hypericum / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism*; D007189:Indans / Q000494:pharmacology*; D063065:Organophosphonates / Q000494:pharmacology*; D010569:Perylene / Q000031:analogs & derivatives / Q000378:metabolism; D010636:Phenols / Q000378:metabolism; D010650:Phenylalanine Ammonia-Lyase / Q000378:metabolism
chemical_list: C411146:2-aminoindan-2-phosphonic acid; D000596:Amino Acids; D000873:Anthracenes; D007189:Indans; D063065:Organophosphonates; D010636:Phenols; D002726:Chlorogenic Acid; D010569:Perylene; C004965:hypericin; D010650:Phenylalanine Ammonia-Lyase