Is stimulation of carotenoid biosynthesis in arbuscular mycorrhizal roots a general phenomenon?
Fester T; Wray V; Nimtz M; Strack D Department of Secondary Metabolism, Leibniz Institute of Plant Biochemistry (IPB), Weinberg 3, D-06120 Halle, Germany. tfester@ipb-halle.de The identification and quantification of cyclohexenone glycoside derivatives from the model legume Lotus japonicus revealed far higher levels than expected according to the stoichiometric relation to another, already determined carotenoid cleavage product, i.e., mycorradicin. Mycorradicin is responsible for the yellow coloration of many arbuscular mycorrhizal (AM) roots and is usually esterified in a complex way to other compounds. After liberation from such complexes it has been detected in AM roots of many, but not of all plants examined. The non-stoichiometric occurrence of this compound compared with other carotenoid cleavage products suggested that carotenoid biosynthesis might be activated upon mycorrhization even in plant species without detectable levels of mycorradicin. This assumption has been supported