de Jong Maaike, Wolters-Arts Mieke, Feron Richard, Mariani Celestina, Vriezen Wim H
Department of Plant Cell Biology, Institute for Water and Wetland Research, Radboud University Nijmegen, Heyendaalseweg 135, Nijmegen, The Netherlands.
Plant J. 2009 Jan;57(1):160-70. doi: 10.1111/j.1365-313X.2008.03671.x. Epub 2008 Oct 4.
Auxin response factors (ARFs) are encoded by a gene family of transcription factors that specifically control auxin-dependent developmental processes. A tomato ARF gene, homologous to Arabidopsis NPH4/ARF7 and therefore designated as Solanum lycopersicum ARF7 (SlARF7), was found to be expressed at a high level in unpollinated mature ovaries. More detailed analysis of tomato ovaries showed that the level of SlARF7 transcript increases during flower development, remains at a constant high level in mature flowers, and is down-regulated within 48 h after pollination. Transgenic plants with decreased SlARF7 mRNA levels formed seedless (parthenocarpic) fruits. These fruits were heart-shaped and had a rather thick pericarp due to increased cell expansion, compared with the pericarp of wild-type fruits. The expression analysis, together with the parthenocarpic fruit phenotype of the transgenic lines, suggests that, in tomato, SlARF7 acts as a negative regulator of fruit set until pollination and fertilization have taken place, and moderates the auxin response during fruit growth.
生长素响应因子（ARFs）由一个转录因子基因家族编码，该家族专门控制生长素依赖的发育过程。发现一个与拟南芥NPH4/ARF7同源的番茄ARF基因，因此命名为番茄ARF7（SlARF7），在未授粉的成熟子房中有高水平表达。对番茄子房更详细的分析表明，SlARF7转录本水平在花发育过程中增加，在成熟花中保持恒定的高水平，并在授粉后48小时内下调。SlARF7 mRNA水平降低的转基因植物形成无籽（单性结实）果实。与野生型果实的果皮相比，这些果实呈心形，由于细胞扩张增加，果皮相当厚。表达分析以及转基因系的单性结实果实表型表明，在番茄中，SlARF7在授粉和受精发生之前作为坐果的负调节因子，并在果实生长过程中调节生长素响应。
