盐藻的室温光抑制

实验用盐藻取自天津塘沽轻工业部制盐研究所，采用ＡＳＰ２培养液为培养基，研究了盐藻的室温光抑制现象，并探讨了盐藻的光保护反应机理，结果表明，盐藻对高辐照有很强的忍耐力，且光合能力的恢复也很强，氯霉素（ＣＡＰ）或二硫苏糖醇（ＤＴＴ）在高光下强烈地加深了对ＰＳＩＩ光化学效率（Ｆｖ／Ｆｍ）和光合量子效率（Φｉ）的抑制，但ＣＡＰ或ＤＴＴ单独作用并不抑制盐藻的光化学系统在低光下的可逆恢复；盐藻在ＣＡＰ＋ＤＴＴ

PHOTOINHIBITION AT ROOM TEMPERATURE IN DUNALIELLA SALINA 1009

Dunaliella salina 1009 possesses a greater tolerance to high irradiance and has a much high rate of recovery of photosynthesis after photoinhibition. Changes in photosynthesis rate and photochemical characteristics in response to high irradiance, followed by recovery at low irradiance, were determined in four groups of Dunaliella salina 1009. They were untreated algae, algas beated with either an inhibition of energy dissipation associated with the Xanthophyll cycle (DTT) or an inhibition of ecoded protein synthesis (CAP), as well as algae beated with a combination of CAP DTT. Treatment of algae with either CAP or DTT resulted in a more pronounced decrease in the rate of photosynthesis subsequent to the treatment at high PFD, but the depression of photochemical efficiency and photo efficiency of photosynthetic oxygen evolution was reversible, i.e., CAP- or DTT-sensitive process didn' t prevent the rapid recovery of photochemical system. However, subsequent to the same exposure, the highest level of depression and a low recovery was observed when these algae were treated with a combination of CAP DTT. This means that CAP or DTT-sensitive process is not completely related in Dunaliella salina 1009. Meanwhile, in algae breated with CAP DTT, DTT, further decrease in the PSll reduction state, as well as the slow decrease in Fm, (the slow increase in non-photochemical quenching), would be consistent with the development of an additional Xanthophyll cycleindependent process that dissipates excess energy in PSII. This apparently develops during high PFD and persists upon return to low PFD. It may cause the photochemical system to reversibly return to a high functional photosynthetic state.