Forward genetic screen for auxin-deficient mutants by cytokinin

0447201 - ÚEB 2016 RIV GB eng J - Journal Article
Wu, L. - Luo, P. - Di, D.W. - Wang, L. - Wang, M. - Lu, C.K. - Wei, S.D. - Zhang, L. - Zhang, T.Z. - Amakorová, Petra - Strnad, Miroslav - Novák, Ondřej - Guo, G.Q.
Forward genetic screen for auxin-deficient mutants by cytokinin.
Scientific Reports. Roč. 5, JUL 6 (2015). ISSN 2045-2322. E-ISSN 2045-2322
R&D Projects: GA MŠMT(CZ) LO1204
Institutional support: RVO:61389030
Keywords : ETHYLENE-INSENSITIVE MUTANTS * YUCCA FLAVIN MONOOXYGENASES * ARABIDOPSIS-THALIANA
Subject RIV: EB - Genetics ; Molecular Biology
Impact factor: 5.228, year: 2015

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.
Permanent Link: http://hdl.handle.net/11104/0249110