Sasan Mohsenzadeh; Sahar Sadeghi; Hassan Mohabatkar; Ali Niazi
Abstract
Osmotic stress is one of the major factors that significantly reduce yields in dry areas. Plants respond to this
abiotic stress at physiological and molecular levels. Many genes are induced under stress conditions by
transcription factors. Dehydration responsive element binding (DREB) protein is a ...
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Osmotic stress is one of the major factors that significantly reduce yields in dry areas. Plants respond to this
abiotic stress at physiological and molecular levels. Many genes are induced under stress conditions by
transcription factors. Dehydration responsive element binding (DREB) protein is a subfamily of AP2/ERF
transcription factors which control expression of many osmotic stress-inducible genes. In this study, 21 days
old seedlings of Sardari cultivar, dry farming bread wheat transferred into hydroponics culture using Hoagland
solution. Osmotic stress treatments performed with adding 100, 200 and 400 g/l poly-ethylene glycol 6000 to
hydroponics culture to obtain –0.15, –0.49, and –1.76 MPa water potential, respectively. After the seedlings
were withered and colorless, relative water content, dry weight, and photosynthesis measured. In addition, RTPCR,
and cDNA sequencing carried out. Molecular analysis of DREB translated protein sequence performed
by DNAMAN, BLASTN, Pfam and PROSITE software. Results showed that osmotic stress decreased relative
water content, root and shoot dry weight and net photosynthesis rate in comparison to control, significantly (P
< 0.05). Sequence alignment indicated 98% homology with other Triticum aestivum DREB protein mRNA.
There was an AP2 domain in the translated protein with three -sheets and one -helix and contains the Val14
and Glu19 amino acids. An EST Sequence deposited in NCBI GenBank database with the accession number of
ES466900.
