@Article{IPB-2155, author = {Fester, T. and Schmidt, D. and Lohse, S. and Walter, M. H. and Giuliano, G. and Bramley, P. M. and Fraser, P. D. and Hause, B. and Strack, D.}, title = {{Stimulation of carotenoid metabolism in arbuscular mycorrhizal roots}}, year = {2002}, pages = {148-154}, journal = {Planta}, doi = {10.1007/s00425-002-0917-z}, volume = {216}, abstract = {Development of arbuscular mycorrhizal roots is correlated with accumulation of various isoprenoids, i.e. acyclic C14 polyene \'mycorradicin\' and C13 cyclohexenone derivatives. We present data indicating a strong stimulation of carotenoid metabolism in such roots. Carotenoid profiling revealed mycorrhiza-specific accumulation of ΞΆ-carotene in Zea mays and Medicago truncatula. Precursor accumulation after inhibition of phytoene desaturase (Pds) activity by norflurazon indicated an increased phytoene biosynthetic capacity in mycorrhizal roots of all species analyzed. Nicotiana tabacum plants transformed with a PDS promoter-GUS construct showed a cell-specific induction of PDS promoter activity in root cells containing arbuscules. Mycorradicin biosynthesis and, partially, mycorrhization were impaired in maize mutants deficient in carotenoid biosynthesis. These data indicate that (1) mycorradicin is probably synthesized via a C40 precursor carotenoid, (2) carotenoid biosynthesis is induced in mycorrhizal roots, (3) induction occurs, at least partially, at the transcriptional level, and (4) that this may play a functional role during mycorrhization.} }