Increased Ac excision (iae): Arabidopsis thaliana mutations affecting Ac transposition

Area of Science:

• Plant molecular biology
• Genetics
• Transposable elements

Background:

• The maize Ac transposable element exhibits high activity in tobacco and tomato but low activity in Arabidopsis.
• Understanding the Arabidopsis host factors limiting Ac activity is crucial for genetic research.

Purpose of the Study:

• To identify Arabidopsis host factors that regulate the activity of the maize Ac transposable element.
• To isolate and characterize mutations that enhance Ac transposition in Arabidopsis.

Main Methods:

• Gamma-ray mutagenesis of Arabidopsis carrying an SPT::Ac reporter construct.
• Screening for variegated phenotypes in the M2 generation on streptomycin-containing medium.
• Complementation analysis and genetic mapping to identify mutations.

Main Results:

• Nineteen mutants with high somatic Ac activity were isolated, falling into two complementation groups (iae1, iae2).
• The iae1 and iae2 mutations caused 550- and 70-fold increases in Ac excision sectors, respectively.
• Molecular analysis confirmed high Ac excision but low re-insertion in iae1 mutants.

Conclusions:

• The identified iae mutants significantly enhance Ac transposable element activity in Arabidopsis.
• These mutants provide a valuable tool for improving Ac/Ds transposon tagging efficiency in Arabidopsis.
• The study facilitates the dissection of host factors involved in transposable element control.