Antisense oligodeoxynucleotide inhibition as a potent strategy in plant biology: identification of SUSIBA2 as a transcriptional activator in plant sugar signalling.
Sugar signalling cascades are important components of regulatory networks in cells. Compared with the situation in bacteria, yeast and animals, participants of the sugar signalling pathways in plants are poorly understood. Several genes involved in starch synthesis are known to be sugar inducible, although the signal transduction pathways remain undisclosed. We reported recently the isolation of SUSIBA2, a transcription factor involved in sugar-mediated regulation of starch synthesis. Here, we used antisense oligodeoxynucleotide (ODN) inhibition, a powerful approach in medical sciences, to block the effects of SUSIBA2 in sugar-treated barley leaves. The uptake and intracellular trafficking of an 18-mer susiba2 antisense ODN in leaves were followed by confocal microscopy. Administration of the antisense ODN to the leaves impeded susiba2 expression by RNase H activation. This dramatically diminished the ectopic expression of the iso1 and sbeIIb genes and resulted in altered starch synthesis. This study illustrates the successful exploitation of the antisense ODN technology in plant biology, e.g. as a rapid antecedent to time-consuming transgenic studies, and identifies SUSIBA2 as a transcriptional activator in plant sugar signalling. Based on our findings, we propose a model for sugar-signalling control of starch synthesis.
Sun
Chuanxin
C
Department of Plant Biology & Forest Genetics, The Swedish University of Agricultural Sciences, PO Box 7080, SE-75007 Uppsala, Sweden.
Höglund
Anna-Stina
AS
Olsson
Helena
H
Mangelsen
Elke
E
Jansson
Christer
C
D018506:Gene Expression Regulation, Plant; D001467:Hordeum / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D020319:Oligodeoxyribonucleotides, Antisense / Q000235:genetics / Q000378:metabolism*; D018515:Plant Leaves / Q000378:metabolism / Q000648:ultrastructure; D010940:Plant Proteins / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D013213:Starch / Q000378:metabolism*; D015534:Trans-Activators / Q000378:metabolism*; D014158:Transcription, Genetic
D020319:Oligodeoxyribonucleotides, Antisense; D010940:Plant Proteins; D015534:Trans-Activators; D013213:Starch