PART I: GENETICS AND ERGOLINE ALKALOID FORMATION IN PENICILLIUM ROQUEFORTII THOM. PART II: BIOSYNTHETIC STUDIES ON ERGOLINE ALKALOID PRODUCTION IN MORNING GLORY PLANTS

SOOBOK LEE HONG, Purdue University

Abstract

Part I. Genetics and Ergoline Alkaloid Formation in Penicillium roquefortii Thom. For the genetic investigation of the formation of ergot alkaloids, organisms other than Claviceps could be considered. One of the fungal species which produces ergot-type alkaloids is Penicillium roquefortii. In this study, genetic markers were introduced in P. roquefortii with N-methyl-N'-nitro-N-nitrosoguanidine and auxotrophic mutants, spore color mutants and mutants with different characters from the wild type in alkaloid production were selected. Utilizing the protoplast fusion technique, the parasexual cycle was demonstrated in this organism and at least four linkage groups were identified: Ylo (yellow spore), Nic (nicotinic acid), His (histidine)-Sts (sensitivity to Sulfatase), and cell growth/alkaloid production belong to separate chromosomes. Part II. Biosynthetic Studies on the Ergoline Alkaloid Formation in Morning Glory Plants. There have been indications that ergolines in the fungus and in the plant are formed from the same precursors and chanoclavine-I serves as an intermediate for the ergoline alkaloid biosynthesis. However, attempts to incorporate the presumed precursors failed. It was found that the slow synthesis and/or rapid turnover of the alkaloids in the plant R. corymbosa were ruled out for the possible explanation for the failure of incorporation of radioactive precursors since ('14)C-CO(,2) was well incorporated into the alkaloids. The ergoline alkaloids were produced in very small quantities by the cell cultures of R. corymbosa, but a cell free extract of the cultures failed to show dimethylallytryptophan synthetase activity.

Degree

Ph.D.

Subject Area

Pharmacology

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