A DREB gene from the xero-halophyte Atriplex halimus is induced by osmotic but not ionic stress and shows distinct differences from glycophytic homologues

作者：Khedr Abdel Hamid A; Serag Mamdouh S; Nemat Alla Mamdouh M; Abo Elnaga Amina Z; Nada Reham M^*; Quick W Paul; Abogadallah Gaber M

来源：Plant Cell, Tissue and Organ Culture, 2011, 106(2): 191-206.

DOI：10.1007/s11240-010-9906-2

• Atriplex halimus
• DREB
• Protein content
• Gene expression
• Salinity
• Osmotic and ionic stress

Studying the regulation of stress inducible genes can lead to understanding of the mechanisms by which halophytes maintain growth and thrive under abiotic stress. Verifying whether ionic or osmotic components of salt stress control the regulation of Dehydration Responsive Element- binding transcription factor (DREB) was investigated in the present study. DREB belongs to AP2/EREB group that is induced under abiotic stress and regulates many stress inducible genes that contain DRE binding sites in their promoters. DREB in Atriplex halimus was regulated by the osmotic component but not by the ionic one of salt stress. It seemed that DREB was not involved in the regulation of sodium manipulating genes like NHX1, SOS1 or H (+)-PPase. Moreover, DREB could be involved directly of indirectly in CMO regulation because of timing of induction. Also, DREB was the most upregulated gene under salt (fivefold) and drought (twofold) conditions, which reinforced the importance of this gene in A. halimus tolerance to stress. Moreover, its constitutive expression under normal conditions also indicated its involvement in other growth and developmental programs. The tolerance of A. halimus and of halophytes, in general, could be attributed to the constitutive expression of its genes and differences in protein structures between halophytes and glycophytes.

• 出版日期2011-8