Competence of Arabidopsis thaliana genotypes and mutants for Agrobacterium tumefaciens-mediated gene transfer: role of phytohormones.
Many plant species and/or genotypes are highly recalcitrant to Agrobacterium-mediated genetic transformation, and yet little is known about this phenomenon. Using several Arabidopsis genotypes/ecotypes, the results of this study indicated that phytohormone pretreatment could overcome this recalcitrance by increasing the transformation rate in the known recalcitrant genotypes. Transient expression of a T-DNA encoded ss-glucuronidase (GUS) gene and stable kanamycin resistance were obtained for the ten Arabidopsis genotypes tested as well as for the mutant uvh1 (up to 69% of petioles with blue spots and up to 42% resistant calli). Cultivation of Arabidopsis tissues on phytohormones for 2-8 d before co-cultivation with Agrobacterium tumefaciens significantly increased transient GUS gene expression by 2-11-fold and stable T-DNA integration with petiole explants. Different Arabidopsis ecotypes revealed differences in their susceptibility to Agrobacterium-mediated transformation and in their type of reaction to pre-cultivation (three types of reactions were defined by gathering ecotypes into three groups). The Arabidopsis uvh1 mutant described as defective in a DNA repair system showed slightly lower competence to transformation than did its progenitor Colombia. This reduced transformation competence, however, could be overcome by 4-d pre-culture with phytohormones. The importance of pre-cultivation with phytohormones for genetic transformation is discussed.
Chateau
S
S
Laboratoire Androgenèse et Biotechnologie, Université de Picardie Jules Verne, 33 rue Saint-Leu, 80039 Amiens cedex 01, France.
Sangwan
R S
RS
Sangwan-Norreel
B S
BS
D016960:Agrobacterium tumefaciens / Q000235:genetics*; D017360:Arabidopsis / Q000235:genetics*; D003470:Culture Media; D046508:Culture Techniques; D015870:Gene Expression; D018014:Gene Transfer Techniques; D017343:Genes, Plant; D005838:Genotype; D005966:Glucuronidase / Q000235:genetics; D009154:Mutation; D010937:Plant Growth Regulators / Q000502:physiology*; D014170:Transformation, Genetic
D003470:Culture Media; D010937:Plant Growth Regulators; D005966:Glucuronidase