Fig. 6.

Arabidopsis thaliana om47 mutants display a stay-green phenotype, and have altered reactive oxygen species accumulation in a dark-induced senescence assay on detached leaves. (A) Individual leaves from A. thaliana wild type (Col-0) and om47 mutants detached from 4-week-old plants and covered for 3 d to induce the senescence process. The right-hand panel shows relative senescence-related chlorophyll breakdown of A. thaliana wild type (Col-0) and om47 mutants before (4-week-old plants, 0 d of dark-induced senescence) and after (3 d of dark-induced senescence) detachment from 4-week-old plants as quantified by using the SPAD 500 chlorophyll meter. Values are relative to the wild type at 0 d of dark-induced senescence. Leaves were detached and placed inside lightproof plates. Five leaves per plant and three plants per genotype were sampled (n=3; data are given as averages; error bars represent ±SE). *Significant differences (P≤0.05) compared with the wild type at each growth stage as determined by Student’s t-test. (B) Reactive oxygen species in the form of O₂ ⁻ from individual leaves of A. thaliana wild type (Col-0) and om47 mutants before (4-week-old plants, 0 d of dark-induced senescence) and after (3 d of dark-induced senescence) detachment from 4-week-old plants.