Changes in the free nucleotide pattern of spores from Phycomyces in relation to heat-induced germination

Research paper by Bodo Furch

Indexed on: 01 Jan '74Published on: 01 Jan '74Published in: Archives of Microbiology


In dry spores the presence of considerable amounts of ATP, UTP and GTP can be demonstrated.During the inbibition phase (stage I of free nucleotide levels) a transient increase of ATP can be observed. The other nucleotide pools (UTP, GTP, AMP, ADP, UDP, CMP, UDP-A) only change little.Spores, transferred in a complete nutrition medium, accumulate ATP, while other nucleotide pools remain constant. Nearly all spores (97%) remain dormant.Heat-shocked spores (3 min at 50°C), incubated in water, are able to accumulate ATP, GTP, and UTP during and in the first minutes after heating; afterwards no further enhancement takes place. Even then most of the spores are unable to overcome dormancy (germination rate about 5–10%).When heat shock is applied to spores in a complete medium, germination will be initiated (germination rate at about 99%). During activation and begining germination the nucleotide levels develop in three more stages: sharp increase of ATP and UTP, decrease of AMP, ADP and UDP levels during heat activation (stage II), leading to a maintenance phase of nearly all nucleotides measured (stage III) and then, two hours after activation to a slight increase of ADP, ATP and ADPA levels while that of UDP decreases (stage IV). Now NADP+NADPH/NAD+NADH-ratio begins to rise too. CMP and UDP levels remain rather constant at all times measured.