IDENTIFICATION OF A YELLOW PIGMENT FORMED IN MAIZE ROOTS UPON MYCORRHIZAL COLONIZATION

Roots of gramineous plants turn deep yellow upon colonization with arb uscular mycorrhizal fungi. At the same time methanolic extracts of mai ze roots show a polyene absorption with maxima at 375 and 395 nm that is not found in the extracts of controls. After esterification with di azomethane the compound responsible for this absorption was isolated b y column chromatography and shown to be all-E-4,9-dimethyldodeca-2,4,6 ,8,10-pentaenedioic acid by NMR and mass spectrometry. The compound pr esumably is derived from oxidative degradation of a carotenoid.