The Solanum lycopersicum auxin response factor 7 (SlARF7) regulates auxin signaling during tomato fruit set and development.
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.
de Jong
Maaike
M
Department of Plant Cell Biology, Institute for Water and Wetland Research, Radboud University Nijmegen, Heyendaalseweg 135, Nijmegen, The Netherlands.
Wolters-Arts
Mieke
M
Feron
Richard
R
Mariani
Celestina
C
Vriezen
Wim H
WH
D000595:Amino Acid Sequence; D005638:Fruit / Q000254:growth & development* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D007210:Indoleacetic Acids / Q000378:metabolism*; D018551:Solanum lycopersicum / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D034622:RNA Interference; D018749:RNA, Plant / Q000235:genetics; D016415:Sequence Alignment; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D007210:Indoleacetic Acids; D010940:Plant Proteins; D018749:RNA, Plant; D014157:Transcription Factors