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Photoprotection by mitochondrial alternative pathway is enhanced at heat but disabled at chilling
Author(s) -
Li YuTing,
Liu MeiJun,
Li Ying,
Liu Peng,
Zhao ShiJie,
Gao HuiYuan,
Zhang ZiShan
Publication year - 2020
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.14931
Subject(s) - photoprotection , photorespiration , photoinhibition , chloroplast , serine , biology , biochemistry , biophysics , arabidopsis , mitochondrion , microbiology and biotechnology , chemistry , photosynthesis , photosystem ii , mutant , gene , enzyme
SUMMARY The mitochondrial alternative pathway (AP) represents an important photoprotective mechanism for the chloroplast, but the temperature sensitivity of its photoprotective role is unknown. In this study, using the aox1a Arabidopsis mutant, the photoprotective role of the AP was verified under various temperatures, and the mechanism underlying the temperature sensitivity of the AP’s photoprotective role was clarified. It was observed that the photoprotective role of the AP increased with rising temperature but was absent at low temperature. The photoprotective role of the AP was severely reduced under non‐photorespiratory conditions. Disturbance of the AP inhibited the conversion of glycine to serine in mitochondria, which may restrain upstream photorespiratory metabolism and aggravate photoinhibition. With rising temperatures, photorespiration accelerated and the restraint of photorespiration caused by disturbance of the AP also increased, determining the temperature sensitivity of the AP’s photoprotective role. We also verified that not only the AP but also the cytochrome pathway in mitochondria contributes to photoprotection by maintaining photorespiration.