Abstract
asymmetric leaves1 (as1) and as2 mutants of Arabidopsis show similar phenotype, such as the formation of asymmetrically lobed and downwardly curled leaves. It has been reported that as1 and as2 mutants also show the abaxialized leaves. The AS1 gene encodes a protein containing two myb repeats. The AS2 gene encodes a plant-specific protein with a domain containing a cysteine repeat and a leucine-zipper-like sequence. To elucidate the molecular function of AS1 and AS2 in the formation of adaxial-abaxial polarity, we isolated several enhancer mutants that enhance the abnormality in the adaxial-abaxial polarity in the leaves of the as1 mutant. One of the enhancer mutants, enhancer of asymmetric leaves2 and asymmetric leaves1 (eal) had abaxialized filamentous leaves in as1and as2 backgrounds. RT-PCR analysis revealed that the accumulation levels of transcripts of genes that affect the abaxialization of leaves were elevated in as2 eal and as1 eal double mutants.
