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ARS Home » Pacific West Area » Wenatchee, Washington » Physiology and Pathology of Tree Fruits Research » Research » Publications at this Location » Publication #245630

Title: Overexpression of several Arabidopsis histone genes increases Agrobacterium-medicated transformation and transgene expression in plants

Author
item Gabriela, Tenea - Romania Technical University
item Spantzel, Joerg - Purdue University
item Lee, Lan-ying - Purdue University
item Zhu, Yanmin
item Lin, Kui - Shanghai University
item Johnson, Susan - Monsanto Biotechnology
item Gelvin, Stanton - Purdue University

Submitted to: The Plant Cell
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/28/2009
Publication Date: 10/9/2009
Citation: Gabriela, T.N., Spantzel, J., Lee, L., Zhu, Y., Lin, K., Johnson, S.J., Gelvin, S.B. 2009. Overexpression of several Arabidopsis histone genes increases Agrobacterium-medicated transformation and transgene expression in plants. The Plant Cell. 21(10):3350-3367.

Interpretive Summary: The different plant species show variable level of susceptibility of Agrobacterium-mediated plant transformation. To answer the question of what are the plant genetic factors control this process, a comprehensive approach involving mutant identification and molecular genetic analysis were carried out. As part of this effort, this manuscript described the investigation of a group of plant genes encoding common plant histone proteins for their roles in Agrobacterium-mediated plant transformation in Arabidopsis. The Arabidopsis histone H2A-1 is important for Agrobacterium-mediated plant transformation. Mutation of HTA1, the gene encoding histone H2A-1, results in decreased T-(transferred) DNA integration into the genome of Arabidopsis roots, whereas over-expression of HTA1 increases transformation frequency. To understand the mechanism by which HTA1 enhances transformation, we investigated the effects of cDNAs encoding numerous Arabidopsis histones on transformation and transgene expression. Transgenic Arabidopsis containing cDNAs encoding histone H2A (HTA), histone H4 (HFO), and histone H3-11 (HTR11) displayed increased transformation susceptibility, whereas histone H2B (HTB) and most histone H3 (HTR) cDNAs did not increase transformation. A parallel increase in transient gene expression was observed when histone HTA, HFO, or HTR11 cDNAs were co-transfected with double- or single-stranded forms of a gusA gene into tobacco protoplasts. However, these cDNAs did not increase expression of a previously integrated transgene. We identified the N-terminal 39 amino acids of H2A-1 as sufficient to increase transient transgene expression in plants. Our results suggest that certain histones enhance transgene expression, protect incoming transgene DNA during the initial stages of transformation, and subsequently increase the efficiency of Agrobacterium-mediated transformation.

Technical Abstract: The Arabidopsis histone H2A-1 is important for Agrobacterium-mediated plant transformation. Mutation of HTA1, the gene encoding histone H2A-1, in the rat5 mutant results in decreased T-(transferred) DNA integration into the plant genome, whereas over-expression of HTA1 increases transformation frequency. To understand the mechanism by which HTA1 enhances transformation, we investigated the effects of over-expressing cDNAs encoding numerous Arabidopsis histones on transformation and transgene expression. Transgenic Arabidopsis containing cDNAs encoding several histone H2A (HTA), histone H4 (HFO), and histone H3-11 (HTR11) displayed increased transformation susceptibility, whereas histone H2B (HTB) and most histone H3 (HTR) cDNAs did not increase transformation. A parallel increase in transient gene expression was observed when the histone HTA, HFO, or HTR11 cDNAs were co-transfected with double- or single-stranded forms of a gusA gene into tobacco protoplasts. However, over-expression of these cDNAs could not increase expression of a previously integrated transgene. We identified a 39 amino acid N-terminal region of H2A-1 that is sufficient to increase transgene expression in plants. We propose that histones which increase Agrobacterium-mediated transformation and transgene expression do so by enhancing reporter and selectable marker transgene expression during the initial stages of transformation, and that this increase is effected by protecting incoming transgene DNA.