Mitochondrial DNA synthesis during fungal spore germination

✍ Scribed by Dunkle, Larry D. ;Etten, James L. ;Brambl, Robert M.

• Book ID: 104761826
• Publisher: Springer-Verlag
• Year: 1972
• Weight: 409 KB
• Volume: 85
• Category: Article
• ISSN: 0003-9276
• DOI: 10.1007/bf00408847

✦ Synopsis

Germinating spores of the fungus Botryodiplodia theobromae incorporated guanine-8-C 14 into both the nuclear DNA and mitochondrial DNA fractions. Ethidium bromide inhibited the synthesis of mitochondrial DNA without having a significant effect on nuclear DNA synthesis or on the rate and extent of spore germination. Rates of leucine and uracil incorporation and of oxygen uptake were not significantly affected by ethidium bromide until germination was nearly completed. Mitoehondrial DNA synthesis is apparently not required for germhmtion of the spores of B. theobromae but is probably essential to continued vegetative growth.

Initiation of fungal spore germination involves activation of numerous biosynthetie systems, most of which presumably require the function of the aerobic respiratory system. During periods of dormancy of fungal spores, these mitochondrial respiratory activities are considerably reduced but increase sharply upon initiation of germination (Allen, 1965;Sussman, 1969). Because of the functional necessity of respiratory activity in spore germination, we have investigated the role of mitochondrial genetic activities in the germination process to learn whether chemical inhibition of mitoehondrial DNA replication consequently inhibits the aerobic respiration and germination of spores.

During germination of the conidia of the fungus Botryodiplodia theobromae Pat., cyeloheximide-sensitive protein synthesis begins immediately upon the onset of germination and subsequently increases