Overexpression of AtHsfB4 induces specific effects on root development of Arabidopsis.
The functions of plant class B-heat shock factors (Hsfs) are not well understood. Hsfs belonging to this group differ from class A-Hsfs in structural features of the oligomerization domain and by the absence of a typical AHA motif for transcriptional activation. AtHsfB4 is expressed in different parts of the plants with highest levels in root tissue. Transgenic Arabidopsis plants overexpressing (OE) HsfB4 by CaMV-35S-promoter showed massively enhanced levels of Hsf mRNAs. The root surface of OE-plants was rough and cells became detached. Crossings with cell type specific root marker lines and confocal laser scanning microscopy provided clear evidence for a duplication of cells in the ground tissue and ectopic layers of lateral root cap (LRC) cells in HsfB4-OE plants. A duplication of endodermis cells occurs already during embryonic development, while the ectopic LRC cells are only detected during postembryonic growth. The mutant phenotypes of Hsf-OE plants are without precedence and indicate that class B-Hsfs may play an important role in root development.
Universität Tübingen, Zentrum für Molekularbiologie der Pflanzen (ZMBP) - Allgemeine Genetik, Auf der Morgenstelle 28, D-72076 Tübingen, Germany.
Tahmina
T
Begum
Rolf
R
Reuter
Friedrich
F
Schöffl
D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D018869:Heat-Shock Response / Q000235:genetics; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D030821:Plants, Genetically Modified; D014157:Transcription Factors / Q000235:genetics
D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; C550535:SCHIZORIZA protein, Arabidopsis; D014157:Transcription Factors