The more and smaller cells mutants of Arabidopsis thaliana identify novel roles for SQUAMOSA PROMOTER BINDING PROTEIN-LIKE genes in the control of heteroblasty.

摘要: Regulation of cell number and size is essential for controlling the shape leaves. Here, we report a novel class Arabidopsis thaliana mutants, more smaller cells 1 (msc1)-msc3, which have increased decreased in msc1 has miR156-resistant mutation SQUAMOSA PROMOTER BINDING PROTEIN-LIKE 15 (SPL15) gene. msc2 msc3 are new alleles paused squint respectively. All msc mutants showed accelerated heteroblasty, phenomenon several morphological traits leaves change along with phase change. Consistent this finding, wild type, at higher nodes (adult leaves) also reduced compared those lower (juvenile leaves). These facts indicate that precocious acquisition adult leaf characteristics may cause alterations cells, heteroblasty plays an important role regulation size. In agreement suggestion, such heteroblasty-associated changes severely inhibited by constitutive overexpression miR156 promoted elevated expression miR156-insensitive forms SPL genes. By contrast, rdr6, sgs3, zip, arf3 arf4 mutations, affect progression had little or no effect on cells. results suggest mainly regulated SPL-dependent pathway rather than tasiR-ARF-dependent pathway.