Identification of mutants with impairments in auxin biosynthesis and dynamics by forward genetic screening is hindered by the complexity, redundancy and necessity of the pathways involved. Furthermore, although a few auxin-deficient mutants have been recently identified by screening for altered responses to shade, ethylene, N-1-naphthylphthalamic acid (NPA) or cytokinin (CK), there is still a lack of robust markers for systematically isolating such mutants. We hypothesized that a potentially suitable phenotypic marker is root curling induced by CK, as observed in the auxin biosynthesis mutant CK-induced root curling 1 / tryptophan aminotransferase of Arabidopsis 1 (ckrc1/taa1). Phenotypic observations, genetic analyses and biochemical complementation tests of Arabidopsis seedlings displaying the trait in large-scale genetic screens showed that it can facilitate isolation of mutants with perturbations in auxin biosynthesis, transport and signaling. However, unlike transport/signaling mutants, the curled (or wavy) root phenotypes of auxin-deficient mutants were significantly induced by CKs and could be rescued by exogenous auxins. Mutants allelic to several known auxin biosynthesis mutants were re-isolated, but several new classes of auxin-deficient mutants were also isolated. The findings show that CK-induced root curling provides an effective marker for discovering genes involved in auxin biosynthesis or homeostasis.

• MeSH
• Arabidopsis enzymologie   genetika   MeSH
• biologický transport účinky léků   MeSH
• cytokininy metabolismus   MeSH
• fenotyp MeSH
• kořeny rostlin enzymologie   genetika   růst a vývoj   MeSH
• kyseliny indoloctové metabolismus   farmakologie   MeSH
• mutace MeSH
• proteiny huseníčku genetika   metabolismus   MeSH
• regulátory růstu rostlin biosyntéza   MeSH
• semenáček účinky léků   růst a vývoj   metabolismus   MeSH
• signální transdukce účinky léků   MeSH
• tryptofantransaminasa genetika   metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH