Agrobacterium-mediated plant transformation is
a core technology for both plant molecular sciences and for agricultural
biotechnology. Although Agrobacterium-mediated transformation
has been used to generate transgenic plants for more than 25 years, many
agronomically important species, or particular genotypes of these species,
remain recalcitrant to transformation.
Scientists have increased transformation frequency by manipulating
tissue culture conditions and by developing highly virulent Agrobacterium strains. As an additional approach, we have
investigated plant genes and proteins important for plant transformation
susceptibility. By characterizing Arabidopsis mutants that are either resistant
or hypersusceptible to Agrobacterium
transformation (rat or hat mutants), we have identified a large
number of host genes involved in the transformation process. In some cases, overexpressing these
“transformation genes” can increase transformation frequency, even in
heterologous plant species such as rice.
I shall describe how we identified and characterized these genes. In particular, I shall describe a plant myb
transcription factor that is a negative global regulator of
transformation. Manipulation of this myb
gene may enhance transformation susceptibility of important crop species.