Role of Glucose and Amino Acids in the Production of Resistant Sporangia by Allomyces macrogynus

Abstract

The selective production of resistant sporangia by A. f1Ulcrogynus required the presence of glucose and a suitable amino acid at the time of transcription of mRNA. Plants suspended in glutamate solution alone made zoosporangia only but the addition of glucose at various times permitted resistant sporangia to develop after 4-5 h, during which time glycogen and trehalose had accumulated to maximum levels. After septation of the resistant sporangium, adequate glucose was still required to complete the acid-resistant wall; otherwise the developing structure reverted to a zoosporangium. Plants suspended in glucose-ammonium citrate solution metabolized glucose without accumulating glycogen or trehalose for 8-9 h and produced only zoosporangia in this time. At and above 12 mM glucose a maximum content of glycogen and trehalose was reached although glucose was still available to the plants.