Genetic interaction between the AS1-AS2 and RDR6-SGS3-AGO7 pathways for leaf morphogenesis. Plant Cell Physiol

In higher plants, class I KNOTTED1-like homeobox (KNOX) gene suppression and leaf polarity establishment are two processes crucial for leaf morphogenesis. The Arabidopsis genes, ASYMMETRIC LEAVES1 and 2 (AS1 and AS2), are required for repressing the class I KNOX genes and promoting leaf adaxial cell fates. In addition, the RNA-DEPENDENT RNA POLYMERASE6 (RDR6) gene acts synergistically with AS1 and AS2 to specify the adaxial polarity and repress the KNOX genes in leaves. It is known that RDR6 is one of the key components in plant post-transcriptional gene silencing (PTGS), and is likely to function with other silencing components in a genetic pathway in regulating leaf patterning. Here we report phenotypic analyses of double mutants combining as1 or as2 with other mutations relating to different RNA silencing pathways