Figure 1.

Detection of the MYB-type GS regulators in the abaxial leaf domain. A to C, Genotypes used for array analysis included the wild type (WT; A), a transgenic plant expressing the KAN gene under the control of the ANT promoter (abaxialized; B), and a plant with a dominant mutation in the PHB gene (adaxialized; C). Microarrays were used to identify abaxial-enriched genes differentially expressed between the adaxial and abaxial leaf domains (see “Materials and Methods”). D and E, Differential mRNA expression levels between the two leaf domains for the three MYB transcription factors (D) and for known markers of GS biosynthesis (E). The mRNA levels are presented as log₂ ratios versus wild-type levels, and in all cases there was a statistically significant difference (P < 0.05) between the genotypes representing either leaf domain.