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Calcium contributes to photoprotection and repair of photosystem II in peanut leaves during heat and high irradiance
Author(s) -
Yang Sha,
Wang Fang,
Guo Feng,
Meng JingJing,
Li XinGuo,
Wan ShuBo
Publication year - 2015
Publication title -
journal of integrative plant biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.734
H-Index - 83
eISSN - 1744-7909
pISSN - 1672-9072
DOI - 10.1111/jipb.12249
Subject(s) - photoinhibition , photosystem ii , photoprotection , reactive oxygen species , chemistry , thylakoid , antioxidant , calcium , quenching (fluorescence) , ascorbic acid , biophysics , superoxide dismutase , chlorophyll fluorescence , chloroplast , biochemistry , radical , photosynthesis , photochemistry , biology , food science , fluorescence , physics , organic chemistry , quantum mechanics , gene
In this study, we investigated the effects of exogenous calcium nitrate on photoinhibition and thylakoid protein level in peanut plants under heat (40 °C) and high irradiance (HI) (1,200 µmol/m 2 per s) stress. Compared with control seedlings (cultivated in 0 mmol/L Ca(NO 3 ) 2 medium), the maximal photochemical efficiency of photosystem II (PSII) in Ca 2+ ‐treated plants showed a slight decrease after 5 h stress, accompanied by lower degree of PSII closure (1‐qP), higher non‐photochemical quenching, and lower level of membrane damage. Ca 2+ inhibitors were used to analyze the varieties of antioxidant enzymes activity and PSII proteins. These results indicated that Ca 2+ could protect the subunits of PSII reaction centers from photoinhibition by reducing the generation of reactive oxygen species. In the presence of both ethyleneglycol‐bis(2‐aminoethylether)‐tetraacetic acid and ascorbic acid (AsA), the net degradation of the damaged D1 protein was faster than that only treated with AsA. Our previous study showed that either the transcriptional or the translational level of calmodulin was obviously higher in Ca 2+ ‐treated plants. These results suggested that, under heat and HI stress, the Ca 2+ signal transduction pathway can alleviate the photoinhibition through regulating the protein repair process besides an enhanced capacity for scavenging reactive oxygen species.