Functional characteristics of <italic>TaPYR1</italic>, an abscisic acid receptor family gene in mediating wheat tolerance to drought stress

Abstract

ABA receptors are involved in the mediation of ABA signaling transduction through interaction with abscisic acid (ABA) molecules induced by osmotic stresses and play critical roles in regulating the drought stress tolerance in plants. In this study, TaPYR1 , an ABA family gene in wheat that was shown to be differentially expressed in our previous transcriptome analysis was used to analyze its molecular property, expression patterns under drought stress condition, and functions in mediating plant adaptation to drought stress. TaPYR1 shares high similarities to its plant counterparts at amino acid level. TaPYR1 protein contains the conserved domains specified by the plant PYR proteins and was targeted onto the plasma membrane after endoplasmic reticulum (ER) assortment. The expression of TaPYR1 was induced in both roots and leaves under drought, with the highest expression levels at 48 h of drought treatment. Transgene analysis on TaPYR1 was performed to assess the gene function in mediating plant drought tolerance. Compared with wild type (WT), the tobacco lines overexpressing TaPYR1 enhanced growth vigor and increased fresh and dry weight under drought stress. In addition, the transgenic lines with TaPYR1 overexpression also increased photosynthetic function, enhanced activities of cellular antioxidant enzymes, and elevated the contents of osmolytes (i.e., proline and soluble sugar) under drought condition. Our investigation suggests that TaPYR1 transcriptively responds to drought stress signaling and plays an important role in regulating plant drought adaptation by improving the associated physiological processes.