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ARS Home » Northeast Area » Kearneysville, West Virginia » Appalachian Fruit Research Laboratory » Innovative Fruit Production, Improvement, and Protection » Research » Publications at this Location » Publication #191000
Title: The second intron of Agamous drives carpel- and stamen-specific expression sufficient to induce complete sterility in Arabidopsis

Author
item Liu, Zongrang
item LIU, ZHONGCHI - UNIVERSITY OF MARYLAND

Submitted to: Plant Cell Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/18/2008
Publication Date: 2/7/2008
Citation: Liu, Z., Liu, Z. 2008. The second intron of Agamous drives carpel- and stamen-specific expression sufficient to induce complete sterility in Arabidopsis. Plant Cell Reports. 27:855-863.

Interpretive Summary: Potential gene flow from transgenic plants into wild or close relatives has drawn attention from the scientific community and consumer, and raised the concern on the ecological and environmental impact of the adoption of transgenic crops. Here, we developed a new technology to make plant complete sterile by tissue-specific eradication of male and female organs in flowers. The transgenic plants we developed showed a complete depletion of male and female organs without affecting flower development and plant growth. This technology can be used for completely preventing transgene flow in these plant species where vegetative growth is of essential economical values (forestry, ornamental species). This technology can also be used for remedying environmental pollution caused by excessive pollen and fruit production by ornamental plants, and preventing the invasiveness of newly introduced or existing exotics used as ornamentals or in forestry.

Technical Abstract: Developing new technology to prevent transgene dispersal through pollen, fruit and seed is imminently needed to address the concern for the ecological and environmental impact of gene flow from transgenic crops into wild types or their close relatives. In this study, we cloned the second intron of the Arabidopsis floral homeotic gene, AG, and fused it with a minimal 35S promoter sequence at 5' and 3' ends to make an expression-capable, sense-oriented promoter, AGIP, and a reverse-oriented promoter, rAGIP, respectively. Analysis of transgenic plants harboring either AGIP::GUS or rAGIP::GUS showed that both promoters specified a very similar expression in carpel and stamen primordia regardless of orientation. To achieve tissue-specific ablation, we fused either the AGIP or rAGIP promoter to a cytotoxic gene DT-A and introduced them into Arabidopsis. Over 90% the transgenic plants harboring either AGIP::DT-A or rAGIP::DT-A showed normal sepals and petals, as well as normal plant growth and development but complete, uniform ablation of both carpel and stamen in all flowers, resulting in absolute sterility. The tissue ablation was stably maintained for two cutback generations analyzed, with no reverted carpel and stamen formation observed. This study is the first report of the achievement of absolute sterility through precise, efficient, and permanent ablation of both male and female flower organs without affecting plant growth and development. This technology can be used for completely preventing transgene flow in these plant species, where vegetative growth is of essential economical value (forestry, ornamental species).