Respirometric characterization of mETC mutants and testing of ROS detection assays in the bryophytes model Physcomitrium patens

This master thesis presents partial physiological characterization of mitochondrial mutants within the moss Physcomitrium patens, employing respirometry data and assessing assays for detecting reactive oxygen species (ROS). The studies implemented, showcase differences in the AOX pathway capacity between the protonema and gametophore stages. In particular protonema tissue is able to carry out respiration when complex IV is blocked by cyanide, utilizing the alternative terminal oxidase AOX. Instead, gametophores shown an increased sensibility to inhibition in respect to protonema. The respirometry analysis carried out on mutants showcase: an increased rate of respiration in complex 4 ko line, confirmed that the respiration detectable in aox deficent line was carried out by complex 4 and the opposite in complex IV ko line. Furthermore, the thesis explores the efficacy of assays designed to detect reactive oxygen species. Results indicate that the tested assays may not be optimal for the unique physiological context of Physcomitrium patens. This finding emphasizes the importance of tailored approaches when studying ROS in moss species and raises critical considerations for future research methodologies