The 5′ untranslated region of the At-P5R gene is involved in both transcriptional and post-transcriptional regulation
The steady-state level of transcripts coding for the pyrroline-5-carboxylate reductase of Arabidopsis (At-P5R) increased under salt and heat stress, mainly because of an enhanced mRNA stability. However, the At-P5R protein level was not induced, and its translation was inhibited at initiation stage and probably also at later stages. Replacement of the 5′ untranslated region (5′UTR) and β-glucuronidase (gus) fusion analysis revealed that the first 92 bp region of the At-P5R 5′UTR was sufficient to mediate transcript stabilization and translation inhibition during salt and heat stresses. Furthermore, the first 92 bp region of the At-P5R 5′UTR was also involved in transcription efficiency in a promoter-dependent manner. The results demonstrated that the stress regulation of At-P5R is complex and involves the 5′UTR which acts at three levels, partly in opposing directions.
Document Type: Research Article
Affiliations: Vakgroep Moleculaire Genetica & Departement Plantengenetica, Vlaams Interuniversitair Instituut voor Biotechnologie, Universiteit Gent, K.L. Ledeganckstraat 35, B-9000 Gent, Belgium
Publication date: April 1, 2001