强光下SO2-3和HCO-3对盐藻叶绿素荧光的影响

EFFECTS OF SO2-3 AND HCO-3 ON CHLOROPHYLL FLUORESCENCE IN DUNALIELLA SALINA 1009

摘要:

强光下（1000μmolm^-2s^-1）用低浓度SO^2-₃（1mmol／L）处理盐藻1h，其Fv／Fm、q_N，q_P和PSⅡ都较暗对照高。随着SO^2-₃浓度（5，25，50，100mmol／L）的提高，Fv／Fm、q_N，q_P和ΦPSⅡ下降。20mmol／L的HCO^-₃可减缓这种下降趋势。强光下1mmol／LHCO^-₃对25mmol／LSO^2-₃产生的光抑制不但没在减弱反而有所加强，提高HCO3-浓度则有减弱作用，尤以50mmol／L的效果最好，而且qN可随HCO^-₃浓度的增高而上升，至100mmol／L才略有下降。低浓度下SO^2-₃（5mmol／L）强光的光抑制在随后的低光条件下（40μmolm^-2s^-1）放置2h能完全恢复，高于此浓度引起的光抑制不能完全逆转。低光下HCO^-₃能促进光抑制的恢复。

Abstract:

An unicellular green alga DUnaliella salina 1009 was used as a plant cell model to study the effects of SO^2-₃ and HCO^-₃ on chlorophyll fluorescence under high light intensity (1000 μmol m^-2s^-1) with measurements by modulation pulse fluorometer (PAM). The initial fluorescence (Fo) was induced by a weak measuring light, and the actinic light was at 150 μmol m^-2s^-11, while maximum fluorescence (Fm) was produced under a strong saturated pulse light (6000 μmol m^-2s^-1). The results indicated that the photosynthesis of D. salina 1009 was stimulated by low concentration of SO^2-₃ (1 mmol/L) under high light intensity (1000 μmol m^-2s^-1) for 1 h. With the increasing concentrations of SO^2-₃ (5, 25, 50, 100 mmol/L),the Fv/Fm, q_N，q_P and PS II in D. salina 1009 decreased, and the photoinhibition was obvious. Photoinhibition induced by SO^2-₃ in the presence of HCO^-₃ under high light intensity was reduced, and could be rapidly recovered under low light intensity(40 μmolm^-2s^-1). The results showed a protective role of HCO^-₃ against the SO^2-₃ damage under high light intensity (1000 μmol m^-2s^-1).