CLONING OF THE DREB2A GENE FROM THE DESERT PLANT Halocnemum strobilaceum D.M. Rizayev, S.G. Sherimbetov, B.Sh. Adilov, S. Kurganov, J.F. Ziyavutdinov A.S. Sadykov Institute of Bioorganic Chemistry, Uzbekistan Academy of Sciences Abiotic stresses, such as drought, high salinity and cold are common adverse
environmental conditions that significantly influence plant growth and productivity
worldwide. Absacisic acid, a phytohormone, (ABA) plays an important role in
physiological and developmental responses as well as in coordination of various stress
signal transduction pathways in plants. DREBs (dehydration responsive element
binding) are important plant transcription factors (TFs) that regulate the expression of
many stress-inducible genes mostly in an ABA-independent manner and play a critical
role in improvement of the abiotic stress tolerance of plants by by interaction with a
DRE/CRT cis-element present in the promoter region of various abiotic stress-
responsive genes.
The study of the DREB group of genes involved in drought tolerance and salt
tolerance of plants naturally growing in the drained part of the Aral Sea used for
defensive planting and sand-fixing, as well as in-depth analysis of the molecular genetic
and biochemical characterization of these genes is one of the topical issues of ecological
genetics and plant stress resistance.
At present, scientists of the Institute of Bioorganic Chemistry named after
Academician O.S. Sadykov by Laboratory of cell technologies of vegetable and plant
growing are studying the DREB2A gene playing key roles in plant stress responses
drought and high salinity in some plant species belonging to the
Chenopodiaceae family
growing under stressful conditions in the desert regions of our republic. From the
halophyte plant
Halocnemum strobilaceum , a part of the HsDREB2A gene was isolated
and the nucleotide sequence was determined.
A partial-length HsDREB2A gene, (GenBank ID: OQ373010), was isolated from
Halocnemum strobilaceum plant. The gene is 464 bp in length and encodes a putative
polypeptide of 154 amino acids.
Although the partial sequence of HsDREB2A shared only moderate identity with
known DREB proteins in other plant species, it contained a conserved AP2/EREBP
domain. We used the Multiple Sequence Alignment program to determine the
AP2/EREBP domains. The DNA-binding domain in
Halocnemum strobilaceum proteins such as APETALA2 and EREBP is located amino acids 4–67, and the DNA
binding site is amino acids 6–33.
These observations provide additional evidence that the sequence we obtained
encoded a DREB family gene.
For the first time, we cloned the gene HsDREB2A from
Halocnemum strobilaceum using the polymerase chain reaction method. The 464-bp long HsDREB2A gene
encoded a putative protein that consisted of 154 amino acid residues. Based on these
results, it is possible to obtain new drought-resistant varieties and lines in the future and
introduce them into practice.