Figure 3: The inhibition effect of DCMU and DBMIB.

DCUM treatment graph shows that after 10 μM DCMU treatment, the electron transport rate of PS II (ETR(II)) declined to zero and the photosynthetic electron transport rates of PS I (ETR(I)) remained low value. This result means that PS II was completely inhibited by DCMU and remaining ETR(I) may come from cyclic electron flow in PS I. DBMIB treatment graph shows that after 10 μM DBMIB treatment, both ETR(I) and ETR(II) declined to zero. This result means that PS II and PS I was completely inhibited by DBMIB meanwhile cyclic electron flow was also cut off.