Figure 2.

Examples of the GUS expression patterns in Arabidopsis senescence-associated enhancer trap lines (Sels). A, GUS expression in senescing leaves of a 5-week-old plate-grown Sel61 plant. B, GUS activities in senescing sepals and receptacle but not in young flower buds of Sel74. C, GUS expression in senescing sepals, stigma, and receptacle of Sel6. D, GUS expression in a senescing stem (right) of Sel25 but not in its young stem (middle). On the left is a senescing stem from a wild-type plant. E, GUS staining in the receptacle, and remains of stigma and style of a senescent silique of Sel74. F, GUS activity in a senescent silique of Sel142. G through I, Induction of GUS expression in Sel142 leaves by ABA (H) and senescence (I) compared with a non-senescing leaf (G). The leaf shown in H is a non-senescing leaf of Sel142 treated with 0.1 mm ABA for 6 h.