The PSI and PSII photoinhibitions were closely related to each
other (Fig. 5). In order to investigate the interrelation between
them, we pretreated the leaves with DCMU to simulate the
decrease of electron accepted by PSI caused by PSII photoinhibition,
or the suppression of PSII electron transport to acceptor side caused
by PSI photoinhibition. This experiment demonstrated that PSII
photoinhibition did not deteriorate PSI photoinhibition but PSI photoinhibition
deteriorated PSII photoinhibition in cucumber leaves.
Maybe it is because that the long-life P700+ caused by PSII photoinhibition
can dissipate excess excitation energy as heat initiatively
[40–42], but the long-life P680 caused by PSI photoinhibition is a