Effect of abiotic stress factors on fluctuations in contents of malate and citrate and on malic enzyme activity in moss gametophores

摘要

Diurnal fluctuations in the contents of malate in gametophores of Polytrichum commune Hedw. and Polytrichum piliferum Hedw. were small. In gametophores of Mnium undulatum Hedw. and leaves of Hieracium pilosella L. significant differences were found in the accumulation of malate between day and night. However, no significant diurnal differences were found in the contents of citrate. High irradiance, desiccation, and submergence by water resulted in increases in daily fluctuations of malate, particularly in the gametophores of P. piliferum and leaves of H. pilosella. Accumulation of malate during night may show the adaptation of the studied species to unfavourable conditions caused by stresses. The change in activity of NADP-malic enzyme may characterize a response to stress factors.