Carotenoid compounds in embryos of wild-type(WT) and viviparous mutants of maize(Zea mays L.) were analyzed using high performance liquid ehromatography (HPLC) with a photodiode array detector. Zeaxanthin accumulates in WT embryos as the major carotenoid. Phytoene accumulates in vp2 and vp5. Phytofluene in w3 and ζ-carotene in the vp9 mutant embryos. This indicates that the vp2 and vp5 mutants impair phytoene desaturase from 15-cis-phytoene to 15-cis-phytofluene. The w3 mutant has neither an isomerase from 15-cis-phytofluene to all-trans-phytofuene nor phytofluene desaturase from phytofluene to ζ-carotene. The vp9 mutant does not have the ζ-carotene desaturase from ζ-carotene to lycopene. Our analysis shows that the terminal carotenoid. γ-carotene(β,ψ-carotene), accumulates in the vp7 mutant embryos. The ε-carotene(ε,ε-carotene), a product of δ-carotene(ε,ψ-carotene) in some plants, however, has not been found in maize embryos. The vp7 mutant impairs a cyclization step from γ-carotene to both β-carotene and α-carotene. We suggest that monocyclic γ-carotene is the sole precursor of both bicyclic β-carotene(β,β-carotene) and α-carotene(β,ε-carotene) in maize.

• Byung-Moo Lee