Functional analysis of Glycin Rich- RNA Binding protein, a suppressor of Trehalose-6-Phosphate mediating growth arrest in Arabidopsis thaliana

Document Type: Research Paper


1 Department of Biology, Faculty of Science, Golestan University, P.O.Box 155, Gorgan, I.R. Iran.

2 Department of Molecular Plant Biology, Institute of Environmental Biology, Utrecht University, Padualaan 8, 3584 CH, The Netherlands.


Metabolism of the alpha-1,1 glucose disaccharide, trehalose, is indispensable in plants. In the Murashige
and Skoog (MS) medium, trehalose inhibits plant growth and allocation of carbon to roots. A suppressor
of trehalose-6-phosphate (T6P) mediated growth arrest, GR-RBP2, is characterized in more detail.
Phylogenetic analysis revealed that GR-RBP2 is a protein of likely prokaryotic origin. A knockout mutant
of GR-RBP2 was identified in the T-DNA insertion line SALK-059714, yet plants of this line were not altered
with regard to growth on different carbon sources and on trehalose compared to WT. GUS expression analysis
showed that GR-RBP2 was detected in adult leaves, flowers and siliques. Expression was particularly
high in root tips. GR-RBP2 expression also is insensitive to 100 mM trehalose. TAP-tagged versions
of this protein showed that GR-RBP2 is part of a protein complex in planta.