Figure 3.

Induction of senescence-related transcripts in O₃-treated Arabidopsis plants. Fifteen-day-old plants were exposed to 0.15 μL L⁻¹ O₃ for 6 h d⁻¹ or remained nontreated. Total RNA was extracted and 3 μg of RNA was separated on 1% formaldehyde-agarose gels, transferred to membranes, and hybridized with the radiolabeled probes indicated. A, Each lane contains RNA extracted from the fifth and sixth leaves pooled from six plants. The samples shown are one representative replicate from a total of three. B, Each lane contains RNA extracted from one rosette and only one replicate was analyzed. C, Control, nontreated plants; O₃, O₃-treated plants.