ETR (I) with or without DBMIB showed CYP37 potential functions in transferring electrons. A) No difference was observed in the ETR (I) of WT and cyp37-1 grown under GL conditions (90 μmol·m−2·s−1) with or without 10 μM DBMIB treatment. WT and cyp37-1 plants were grown under GL for 5 wk, then detached leaves were treated with mock or 10 μM DBMIB in the dark for 2 h and then used for ETR (I) determination. Data represent the means ± Sd, n = 3. PPFD, photosynthetic photon flux density. B) NBT staining showed that superoxide radical accumulation was the same as WT in cyp37-1 mutant plants under GL conditions with or without 10 μM DBMIB treatment. Scale bars: 0.5 cm. C)cyp37-1 mutant showed a similar level of ETR (I) as that observed in WT plants treated with 10 μM DBMIB under HL conditions (350 μmol·m−2·s−1). WT and cyp37-1 plants were grown in GL conditions for 5 wk and then exposed to HL conditions for 4 d. The leaves were treated with mock or 10 μM DBMIB in the dark for 2 h and then used for ETR determination. Data represent the means ± Sd, n = 3. D) The cyp37-1 mutant showed a similar level of ROS accumulation as that observed in WT plants treated with 10 μM DBMIB under HL stress conditions.
