Stimulation of cyclic electron flow during recovery after chilling-induced photoinhibition of PSII.
Although cyclic electron flow (CEF) is essential for repair of PSII, it is unclear whether the CEF is stimulated and what the role of stability of PSI is during the recovery. In order to explore these two questions, mature leaves of Dalbergia odorifera were treated with the chilling temperature of 4°C under a photosynthetic flux density (PFD) of 650 μmol m(-2) s(-1) for 2 h and then were transferred to 25°C under a PFD of 100 μmol m(-2) s(-1) for recovery. The maximum quantum yield of PSII (F(v)/F(m)), the maximum photo-oxidizable P700 (P(m)), the energy distribution in PSII and the redox state of P700 at 25°C under a PFD of 100 μmol m(-2) s(-1) were determined before and after chilling treatment and during subsequent recovery. We found that the CEF was significantly stimulated during the recovery after photodamage. There is a significant positive correlation between stimulation of CEF and photodamage of PSII during recovery. Our results indicated that CEF was significantly stimulated in order to enhance the synthesis of ATP for the fast repair of PSII. The stability of PSI activity favored the fast repair of PSII activity through stimulation of CEF.
Huang
Wei
W
Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, PR China.
Zhang
Shi-Bao
SB
Cao
Kun-Fang
KF
D003080:Cold Temperature; D035782:Dalbergia / Q000502:physiology*; D004579:Electron Transport; D008027:Light; D010084:Oxidation-Reduction; D010788:Photosynthesis; D045332:Photosystem II Protein Complex / Q000037:antagonists & inhibitors* / Q000378:metabolism; D018515:Plant Leaves / Q000502:physiology
D045332:Photosystem II Protein Complex