Translational regulation conferred by the 3’untranslated region of a transcript encoding a late embryogenesis abundant protein in response to water deficit.

BATTAGLIA M. AND COVARRUBIAS AA

Merida, Mexico

Congreso; ASPB (American Society of Plant Biology). Plant Biology 2008; 2008

ASPB

In response to water deficit, higher plants induce a high accumulation of several transcripts including those encoding the late embryogenesis abundant (LEA) proteins. To assure an efficient protein production under this stress condition, some of these transcripts seem to be modulated at the translational level. Because in plants, little is known about the mechanisms involved in the selective translation that usually occurs in response to different environmental stimuli, in this work we analyse the role of the 3, untranslated region (UTR) of the water deficit responsive gene PvLEA18 from Phaseolus vulgaris on the regulation of its expression. Using constructs containing the GUS reporter gene with and without the PvLEA18 3,UTR, driven by the PvLEA18 promoter, and introduced into Arabidopsis plants, we demonstrate that the PvLEA18 3,UTR allows a preferential polysome loading of the GUS reporter transcript under water deficit. We also show that a protein(s) is able to specifically interact with this 3,UTR, and we identify particular sequences that play an important role in this interaction. Our data strongly support a major role of this 3,UTR and some mRNA binding proteins in the selective translational enhancement of the PvLEA18 mRNA, which lead to an efficient protein synthesis and hence a competent response to this stress condition.