Relation between the low temperature stress and catalase activity in gladiolus somaclones (Gladiolus grandiflorus Hort.)

In order to evaluate low temperature tolerance of five variable somaclones as well as the cv. Peter Pears of gladiolus (Gladiolus grandiflorus Hort.) from which they were originated, catalase (CAT) activity and hydrogen peroxide (H₂O₂) level were measured. Before carrying out the analyses, vitroplants of these clones were exposed, during 21 days, to 8 °C temperature. In response to the stress generated by this low temperature, catalase (CAT) activity revealed on native gel and quantified by spectrophotometry, showed variable levels, being all of them higher compared to cultivar control. For these clones, strong CAT activities were always accompanied by low H₂O₂ levels. Thus, at low temperatures the antioxidants system of adapted clones is more active compared to control.