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Different B‐ T ype Methionine Sulfoxide Reductases in Chlamydomonas May Protect the Alga against High‐ L ight, Sulfur‐ D epletion, or Oxidative Stress
Author(s) -
Zhao Lei,
Chen Mei,
Cheng Dongmei,
Yang Haomeng,
Sun Yongle,
Zhou Heyi,
Huang Fang
Publication year - 2013
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.12104
Subject(s) - chlamydomonas reinhardtii , chlamydomonas , oxidative stress , methionine sulfoxide reductase , methionine , biochemistry , sulfur , oxidative phosphorylation , methionine sulfoxide , biology , chemistry , biophysics , microbiology and biotechnology , gene , amino acid , organic chemistry , mutant
The genome of unicellular green alga Chlamydomonas reinhardtii contains four genes encoding B‐type methionine sulfoxide reductases, MSRB1.1 , MSRB1.2 , MSRB2.1 , and MSRB2.2 , with functions largely unknown. To understand the cell defense system mediated by the methionine sulfoxide reductases in Chlamydomonas , we analyzed expression and physiological roles of the MSRBs under different abiotic stress conditions using immunoblotting and quantitative polymerase chain reaction (PCR) analyses. We showed that the MSRB2.2 protein was accumulated in cells treated with high light (1,300 µE/m 2 per s), whereas MSRB1.1 was accumulated in the cells under 1 mmol/L H 2 O 2 treatment or sulfur depletion. We observed that the cells with the MSRB2.2 knockdown and overexpression displayed increased and decreased sensitivity to high light, respectively, based on in situ chlorophyll a fluorescence measures. We also observed that the cells with the MSRB1.1 knockdown and overexpression displayed decreased and increased tolerance to sulfur‐depletion and oxidative stresses, respectively, based on growth and H 2 ‐producing performance. The physiological implications revealed from the experimental data highlight the importance of MSRB2.2 and MSRB1.1 in protecting Chlamydomonas cells against adverse conditions such as high‐light, sulfur‐depletion, and oxidative stresses.