Premium
Parallel analysis of transcript levels and physiological key parameters allows the identification of stress phase gene markers in Chlamydomonas reinhardtii under copper excess
Author(s) -
LUIS PATRICIA,
BEHNKE KATJA,
TOEPEL JÖRG,
WILHELM CHRISTIAN
Publication year - 2006
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/j.1365-3040.2006.01579.x
Subject(s) - chlamydomonas reinhardtii , photosynthesis , reactive oxygen species , biology , gene , oxidative stress , microbiology and biotechnology , chlamydomonas , gene expression , biochemistry , botany , mutant
Excessive copper concentrations, known to induce reactive oxygen species (ROS) formation, have been tested with respect to their effects on transcript abundance and related proteins involved in oxidative stress responses. The results show that the stromal photosynthetic functions were more ROS sensitive than the membrane‐located reactions. The rbcL over‐expression compensated for the damage only at 10 µ m Cu, whereas the genetic stimulation of α ‐tocopherol biosynthesis led to the protection of membrane reactions up to 50–100 µ m Cu. For this reason, the gradual growth drop of Chlamydomonas reinhardtii cultures observed under increasing Cu 2+ concentrations matched better with the loss of photosynthetic capacity than with those of photosynthetic quantum yields. According to Larcher’s stress concept, the results allow the identification of gene markers for the alarm ( rbcL ), the hardening ( FeSOD , VTE3 ) and the exhaustion [cyclin‐dependent protein kinase ( cdk ), psbA ] phases. These genes can be used to rapidly evaluate the state of oxidative stress in algae and putatively in other plant cells.