*2.9. E*ff*ect of Chilling Stress on Cell Death during Greening*

We further examined the effect of low temperature on cell death of leaves using Trypan-blue staining (Figure 10). Few cells could be stained at 28 ◦C, but the number of dead cells significantly increased under low temperatures during greening, especially at 12 ◦C. These results indicate that the low temperature aggravated cell death during greening.

**Figure 10.** Effect of chilling stress on cell death of rice seedlings. Six day old etiolated seedlings were treated with 18 ◦C or 12 ◦C chilling stress. Phenotypes of rice leaves at different time points (**A**); Trypan-blue staining (**B**) of control (28 ◦C) and chill-stressed (18 ◦C and 12 ◦C) leaves after 0 h, 0.5 h, 12 h, and 48 h greening.
