FIGURE 1.

Yellowing and abscission of sepals in Ler-0 and ag-1 plants. (A) 8 week-old Ler-0 plant. (B) 8 week-old ag-1 plant. (C) Ler-0 flowers detached from 8 week-old plant. (D) ag-1 flowers detached from 8 week-old plant. (E) Position of flowers showing yellowing and abscission in 8 week-old Ler-0 and ag-1 plants. Plants were grown under long-day conditions for 8 weeks in a growth room (20–22°C, 16-h light and 8-h dark cycle, white light ∼180 μE and 60% relative humidity) and flowers were detached and subsequently photographed. The yellow and red arrows indicate flowers with senesced and abscised sepals, respectively. The white arrows indicate the flowers used for quantifying delayed sepal senescence for Figure 2D. The flowers are numbered according to the numbering system of Bleecker and Patterson (1997). The numbers in (C,D) indicate the positions of the flowers/siliques along the flowering stalk: flower 1 is the first opened flower present at the top, whereas the high numbers are the flowers/siliques present at the bottom of the stalk. The ag-1 flower is composed of a repeating series of sepal-petal-petal and when whorls of petals abscises, the inner sepal whorl, green in color, appears. This can be seen by reduction in the ag-1 flower size after flower position 20 in (D). The photographs shown are representative of six to eight biological replicates. The error bars indicate standard errors of the mean of eight biological replicates. ^∗Indicates statistically significant (p < 0.05) between Ler-0 and ag-1 using Student’s t-test.