title: BAC-recombineering for studying plant gene regulation: developmental control and cellular localization of SnRK1 kinase subunits.
abstract: Recombineering, permitting precise modification of genes within bacterial artificial chromosomes (BACs) through homologous recombination mediated by lambda phage-encoded Red proteins, is a widely used powerful tool in mouse, Caenorhabditis and Drosophila genetics. As Agrobacterium-mediated transfer of large DNA inserts from binary BACs and TACs into plants occurs at low frequency, recombineering is so far seldom exploited in the analysis of plant gene functions. We have constructed binary plant transformation vectors, which are suitable for gap-repair cloning of genes from BACs using recombineering methods previously developed for other organisms. Here we show that recombineering facilitates PCR-based generation of precise translational fusions between coding sequences of fluorescent reporter and plant proteins using galK-based exchange recombination. The modified target genes alone or as part of a larger gene cluster can be transferred by high-frequency gap-repair into plant transformation vectors, stably maintained in Agrobacterium and transformed without alteration into plants. Versatile application of plant BAC-recombineering is illustrated by the analysis of developmental regulation and cellular localization of interacting AKIN10 catalytic and SNF4 activating subunits of Arabidopsis Snf1-related (SnRK1) protein kinase using in vivo imaging. To validate full functionality and in vivo interaction of tagged SnRK1 subunits, it is demonstrated that immunoprecipitated SNF4-YFP is bound to a kinase that phosphorylates SnRK1 candidate substrates, and that the GFP- and YFP-tagged kinase subunits co-immunoprecipitate with endogenous wild type AKIN10 and SNF4.
authors.affiliation: Max-Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, D-50829 Cologne, Germany.
authors.forename: Marta
authors.initials: M
authors.lastname: Bitrián
authors.forename: Farshad
authors.initials: F
authors.lastname: Roodbarkelari
authors.forename: Mihály
authors.initials: M
authors.lastname: Horváth
authors.forename: Csaba
authors.initials: C
authors.lastname: Koncz
mesh_terms: D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics*; D022202:Chromosomes, Artificial, Bacterial; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D050939:Gene Fusion; D005818:Genetic Engineering / Q000379:methods*; D005822:Genetic Vectors; D008969:Molecular Sequence Data; D030821:Plants, Genetically Modified / Q000235:genetics; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D011995:Recombination, Genetic; D012231:Rhizobium; D014170:Transformation, Genetic
chemical_list: D029681:Arabidopsis Proteins; D017346:Protein Serine-Threonine Kinases; C531469:At3g01090 protein, Arabidopsis