Intracellular polyphosphate is a P reserve in Chlamydomonas reinhardtii
2022
Plouviez, M. | Oliveira da Rocha, C.S. | Guieysse, B.
The changes in cellular phosphorus (P) content and granular polyP abundance were recorded in Chlamydomonas reinhardtii wildtype 1690 incubated under three different conditions of P supply. For this purpose, all biological replicates were photosynthetically grown on low P media (1 mg-P·L⁻¹) for 5 days before receiving an initial P supplementation of 10 mg-P·L⁻¹. A first set of these cultures was subsequently incubated under continuous illumination for 4 days. To prevent polyP consumption, a second set of cultures was subsequently incubated in the dark for 4 days and a third set was incubated under continuous illumination and supplemented 2 mg-P·L⁻¹ 24, 48, and 72 h after the initial P supplementation. In all conditions, P repletion was followed by rapid phosphate uptake and polyP synthesis (0–24 h). Following this initial response, the cellular P content and polyP abundance decreased in cells only supplied P initially and incubated under light, while these parameters remained stable in cells incubated in darkness and cells daily fed P under continuous illumination. Cellular growth was neither impacted by polyP synthesis nor its consumption. These results suggest that under the experimental conditions tested, polyP was used as a reserve of P in the absence of readily available extracellular P and that it was not used as an energy source in darkness.
显示更多 [+] 显示较少 [-]