Fluorescence of Wheat with Incompletely Developed Chloroplast Membranes

Low temperature (77K) fluorscenee emission spectrum of the incompletely developecl chloroplast membranes of wheat, and the fluorescence induction transient of its intact leaf at room temperature were studied. The main peaks of the fluorescence emission spectrum of the incompletely developed chloroplast membranes were at 685 nm and 725 nm respectively. The positions of these two' peaks were almost the same as that in chlorophyll bless mutant barley Chlorina f2. This showed that the incompletely develop- ed chloroplast membranes of wheat did not develope peripheral antenna of PSI but only contained internal antenna of PSI as the case of Chlorina f2. The fluorescence induction transient of wheat leaf with incompletely developed chloroplast membranes did not show the typical time course of O→P→S→M→T and lacked second peak (M) and showed a slow decline as P decayed. This is the same as that of Chlorina f2 leaf. The fluorescence rise in induction period of the leaf with incompletely developed chloroplast membranes was much different from that of normal wheat leaf. These results can be explained by our previous assumption3] that the occurence of typical fluorescence induction transient is based on the coexistence of LHCP of PSII and peripheral antenna of PSI and on their cooperation with each other.