Figure 4.

Ethylene impairs stomatal closure induced by ABA treatment in planta. A, Expression patterns of an ABA-induced gene, RAB18, were compared between before and after ABA treatment. mRNA was extracted from leaves of wild-type plants before treatment (white bars) and after irrigation with 100 μm ABA (black bars) for 30 min. Gene expression levels were measured by real-time quantitative PCR, and the relative amounts of transcripts then calculated and normalized with actin7 mRNA. Bars represent the means ± ses (n = 4–8). B, Time-course changes in stomatal apertures after ABA irrigation of wild type (white circles), wild type exposed to ethylene gas (black squares), and eto1-1 plants (black circles).