Responses of sunflower chlorophyll mutants to increased temperature and oxidative burst

A tolerance of nuclear, plastome, and mitochondrial mutants of sunflower (Helianthus annuus L.) to extreme factors, increased temperature and oxidative stress, which was simulated by hyperbaric oxygenation was studied. In model experiments, activities of superoxide dismutase and catalase were assayed; cytogenetic analysis was used for the assessments of proliferative activity of cells in the root meristem; in field experiments, seedling emergence and growth at the stage of 3–4 leaf pair were evaluated. Most tolerant to increased temperature and oxygen pressure were a plastome en:chlorina-5 mutant and a partial revertant pr6-en:chlorina-7 with a changed structure of mitochondrial DNA.