Abstract
The ASYMMETRIC LEAVES1 (AS1) and AS2 genes in Arabidopsis thaliana are involved in the establishment of the determinate state of cells in leaves by negatively regulating the expression of both class 1 KNOX genes and abaxial determinants, such as ETT, KAN2, and YAB5 genes in the leaf primordia. When leaf sections of as1 and as2 mutants are incubated on MS medium without exogenous phytohormones, the frequency of shoot regeneration increased as compared to leaf sections of wild-type. We found that mutations in class 1 KNOX genes have no effect on the ability to regenerate shoots in as2 and as1 mutants. To examine whether ett/arf3 and arf4 mutation affect on the regeneration of shoots from leaf sections of as1 and as2 mutants. Frequencies of shoot regeneration from leaf section of the as1 ett arf4 and as2 ett arf4 triple mutants were reduced to those of the wild-type plants, indicating that the potential for formation of shoots in the as1 and as2 mutant was caused by the increased expression of ETT/ARF3 and ARF4 genes. These data suggested that ETT and ARF4 may be involved in shoot regeneration from leaf section in vitro in as2 or as1 mutant background in these mutants.
