红光和远红光处理引起的杜氏盐藻跨类囊体膜质子动力势变化

照射远红光后杜氏盐藻毫秒延迟发光快相强度明显增加,而红光处理结果则相反.低温条件明显抑制远红光引起的毫秒延迟发光快相强度的上升,而红光则仍能够有效地引起毫秒延迟发光快相强度的降低.加入消除跨类囊体膜质子梯度的尼日利亚菌素后,远红光不能引起延迟荧光强度的上升.与以前在高等植物中得到的结果相比,在杜氏盐藻中远红光处理后毫秒延迟发光快相强度增加的幅度更大,红光处理后没有出现毫秒延迟发光快相强度先增加后降低的现象.

Changes in Trans-thylakoid Membrane Proton Motive Force Induced by Treatments with Red and Far-red Light in Dunaliella salina

The changes in trans-thylakoid mem-brane proton motive force caused by red light andcaused by far-red light in the halotolerant green alga,Dunaliella salina are investigated. Irradiation withred light decreased the intensity of the fast phase ofmillisecond delayed light emission (ms-DLE) in D.salina, and far-red light led to the opposite effects(Fig.1). Under low temperature conditions (4oC ),red light still decreased ms-DLE fast phase intensity,however, far-red light did not enhance the ms-DLEfast phase intensity as it did at room temperature(Fig.2). In the presence of the uncoupler, nigericin,which eliminates the proton gradient across the thy-lakoid membrane, there was still a decrease in ms-DLE after red light irradiation, while far-red lighthad no stimulatory effects anymore (Fig.3). The far-red light-induced increase in ms-DLE fast phase isthus suggested to be due to the proton gradient formed by water oxidation in photosystem II. Pre-vious studies with higher plants revealed that far redlight increased ms-DLE fast phase intensity slightly,while red light caused a transient increase in ms-DLE fast phase intensity followed by a gradualdecrease. Taken together, green algae differ fromhigher plants with respect to red light- and far redlight-induced changes in ms-DLE. The possible rea-son is discussed.