Early and multiple Ac transpositions in rice suitable for efficient insertional mutagenesis

Area of Science:

• Plant molecular biology
• Genetics
• Biotechnology

Background:

• The Ac transposon is a key tool for genetic research in plants.
• Understanding transposon behavior is crucial for genetic manipulation and gene function studies.

Purpose of the Study:

• To develop a GFP excision assay for monitoring Ac transposon activity in rice.
• To investigate the relationship between early Ac excision and transposon amplification.
• To assess the potential of Ac transposons for insertional mutagenesis and reverse genetics in rice.

Main Methods:

• Development of a GFP excision assay for Ac transposon monitoring in rice.
• Agrobacterium-mediated transformation of rice.
• Excision fingerprint analysis and characterization of transposition events.
• DNA sequencing of flanking regions at Ac insertion sites.
• Segregation analysis of Ac elements.

Main Results:

• A GFP excision assay effectively monitored Ac excision in rice.
• Early excision events, induced by CaMV 35S promoter enhancers, led to Ac amplification.
• Transposition occurred at 15-50% frequency, generating multiple, heritable insertions.
• Sequencing of flanking DNA provided tagged sites for reverse genetics.
• Two-thirds of Ac tagged sites showed homology to known or predicted genes, suggesting efficient gene knockout recovery.

Conclusions:

• The developed assay facilitates the study of Ac transposon dynamics in rice.
• Early Ac excision is linked to transposon amplification, offering a strategy for generating diverse insertion lines.
• Ac transposon tagging in rice is an efficient tool for reverse genetics, with a high probability of targeting functional genes.