Regulation of Photochemical Energy Transfer Accompanied by Structural Changes in Thylakoid Membranes of Heat-Stressed Wheat

International Journal of Molecular Sciences

Yoko Marutani¹  Yasuo Yamauchi¹  Akihito Miyoshi²  Kanako Inoue¹  Ken-ichi Ikeda¹  Masaharu Mizutani¹  Yukihiro Sugimoto¹ 

[1] Graduate School of Agricultural Science, Kobe University, 657-8501 Kobe, Japan; E-Mails:;Faculty of Agriculture, Kobe University, 657-8501 Kobe, Japan; E-Mail:

关键词: heat stress;    state transition;    wheat;    thylakoid membrane;    photosystem;    phosphorylation;   

DOI  :  10.3390/ijms151223042

来源: mdpi

【 摘 要 】

Photosystems of higher plants alleviate heat-induced damage in the presence of light under moderate stressed conditions; however, in the absence of light (i.e., in the dark), the same plants are damaged more easily. (Yamauchi and Kimura, 2011) We demonstrate that regulating photochemical energy transfer in heat-treated wheat at 40 °C with light contributed to heat tolerance of the photosystem. Chlorophyll fluorescence analysis using heat-stressed wheat seedlings in light showed increased non-photochemical quenching (NPQ) of chlorophyll fluorescence, which was due to thermal dissipation that was increased by state 1 to state 2 transition. Transmission electron microscopy revealed structural changes in thylakoid membranes, including unstacking of grana regions under heat stress in light. It was accompanied by the phosphorylation of thylakoid proteins such as D1 and D2 proteins and the light harvesting complex II proteins Lhcb1 and Lhcb2. These results suggest that heat stress at 40 °C in light induces state 1 to state 2 transition for the preferential excitation of photosystem I (PSI) by phosphorylating thylakoid proteins more strongly. Structural changes of thylakoid membrane also assist the remodeling of photosystems and regulation of energy distribution by transition toward state 2 probably contributes to plastoquione oxidation; thus, light-driven electrons flowing through PSI play a protective role against PSII damage under heat stress.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.