Most of higher plants have leaves with adaxial-abaxial polarity. Adaxial region is specified by adaxial-specific genes, whereas abaxial region is specified by abaxial-specific genes. However, it is still unknown how the expression patterns of adaxial-specific or abaxial-specific genes are established. <br>We analyzed novel adaxial-abaxial mutant, <i>enlarged fil expression domain1</i> (<i>enf1</i>). <i>enf1</i> mutant had some leaves which lost robustness of adaxial-abasial polarity. <i>ENF1</i> gene encoded SUCCINIC SEMIALDEHYDE DEHYDEROGENASE (SSADH), which is one of GABA shunt enzymes. We analyzed another mutant of GABA shunt enzymes, <i>gabat1> mutant. <i>gabat1> mutant showed weak abaxializing phenotype and suppressed <i>enf1</i>. We will discuss how GABA shunt regulates the polarity along adaxial-abaxial axis.