Abstract
In higher plants leaves develop from the shoot apical meristem (SAM). Leaf primordia initiate from the cells in the peripheral zone of SAM and develop along three axes, namely the proximal-distal, medial-lateral and adaxial-abaxial axes and finally flat and symmetric. ASYMMETRIC LEAVES2 (AS2) and AS1 genes in Arabidopsis maintain their differentiated state by repressing meristem-related class 1 KNOX genes and leaf abaxial genes. Mutants in as1 and as2 exhibit abaxial leaves. Recently ribosome-related genes were reported to promote leaf adaxial polarity. We treated wild-type, as1, and as2 plants with HT-2 and fusidic acid, which are inhibitors of 60S ribosome subunit and elongation factor 2, respectively. HT-2 treatment caused severe growth inhibition in all the plants, and defects in true leaf development in as1 and as2 plants. Fusidic acid treatment resulted in abaxialized leaves in as1 and as2 plants. These results indicate that targets of these two compounds enhance AS1/AS2 functions.
