T-DNA and transposon tagging in aspen

Area of Science:

• Plant molecular biology
• Genetics
• Biotechnology

Background:

• Gene isolation in trees is challenging due to long generation cycles.
• Transposon-based gene tagging offers a potential solution for efficient gene discovery.
• The maize Activator (Ac) element is a well-characterized transposon system.

Purpose of the Study:

• To develop an efficient transposon-based system for gene isolation in the model tree species Populus (aspen).
• To investigate the somatic activity of the maize Activator (Ac) element in haploid and diploid aspen.
• To assess the potential of Ac for gene tagging and mutant generation in trees.

Main Methods:

• Transformation of aspen with constructs containing the maize Activator (Ac) element and the rolC gene.
• Regeneration of haploid aspen lines from immature pollen.
• Analysis of T-DNA flanking regions in transformed variants and wild-type lines.

Main Results:

• The Activator (Ac) element showed somatic activity in both haploid and diploid aspen.
• Ac frequently reinserted into or near coding regions in aspen, indicating its suitability for gene tagging.
• Phenotypic variants were observed following transformation, with T-DNA insertions occurring in or near coding regions.
• Ac insertion into coding sequences was approximately twice as frequent as T-DNA insertion.

Conclusions:

• Transposon tagging using the Activator (Ac) element is feasible in aspen, providing a proof-of-concept for tree systems.
• Ac activity in haploid aspen enables gene tagging strategies for both gain-of-function and loss-of-function mutants.
• This system holds promise for accelerating gene discovery and functional genomics in trees with long generation times.