S, 1989, Asparagine and regulation of photoinduced rhythm in Penicillium claviforme. Plant, A photosensitive reaction involved in the expression and regulation of the endogenous sporulation rhythm in Penicillium claviforme Bainier CBS 126-23 has been described earlier by our team. The present work shows that asparagine plays a central role in this periodic system. The 24-26 h periodicity, which becomes desynchronized over a few days, was affected by supplying asparagine (1 to 25 mM), a) The rhythm remained synchronized for at least 3 weeks, for all the asparagine concentrations used, b) The period increased successively from one cycle to the next (from 35 ± 3 h to 73 ± 8 h over 6 cycles) for 1 mM asparagine. This period lengthening became less and less accentuated as the asparagine concentration was increased. At > 10 mM, the period was stable; it was 33 + 5 h for 10 mM and 22 ± 1,5 h for 25 mM asparagine. Otherwise asparagine could not elicit rhythmicity in darkness or in dim continuous light (< 5 [i'W m-).

A photosensitive reaction involved in the expression and regulation of the endogenous sporulation rhythm in Penicillium claviforme Bainier CBS 126‐23 has been described earlier by our team. The present work shows that asparagine plays a central role in this periodic system. The 24–26 h periodicity, which becomes desynchronized over a few days, was affected by supplying asparagine (1 to 25 mM). a) The rhythm remained synchronized for at least 3 weeks, for all the asparagine concentrations used, b) The period increased successively from one cycle to the next (from 35±3 h to 73±8 h over 6 cycles) for 1 mM asparagine. This period lengthening became less and less accentuated as the asparagine concentration was increased. At ≥10 mM, the period was stable; it was 33±5 h for 10 mM and 22±1.5 h for 25 mM asparagine. Otherwise asparagine could not elicit rhythmicity in darkness or in dim continuous light (≤5 μW m−2).