Abstract
The Senescence Associated Receptor Protein Kinase (PSARK) promoter, fused to isopentenyltransferase (IPT) gene has been shown to promote drought tolerance in crops. We dissected PSARK in order to understand the various elements associated with its activation and suppression. The activity of PSARK was higher in mature and early senescing leaves, and abiotic stress induced its activity in mature leaves. Bioinformatics analysis suggests the interactions of multiple cis-acting elements in the control of PSARK activity. In vitro gel shift assays and yeast one hybrid system revealed interactions of PSARK with transcription factors related to abscisic acid and cytokinin response. Deletion analysis of PSARK, fused to GUS-reporter gene was used to identify specific regions regulating transcription under senescence or during drought stress. Effects of exogenous hormonal treatments were characterized in entire plants and in leaf disk assays, and regions responsive to various hormones were defined. Our results indicate a complex interaction of plant hormones and additional factors modulating PSARK activity under stress resulting in a transient induction of expression.
| Original language | English |
|---|---|
| Pages (from-to) | 39-47 |
| Number of pages | 9 |
| Journal | Plant Science |
| Volume | 193-194 |
| DOIs | |
| State | Published - Sep 2012 |
Bibliographical note
Funding Information:The authors thank A. Hutmacher and D. Wang for their technical assistance. This study was supported by the Will W. Lester Endowment of University of California . C.A.D. was supported by a fellowship from CAPES Foundation (Brazil). Z.P. was supported by Vaadia-BARD postdoctoral Fellowship Award (FI-419-08) from the US-Israel Binational Agricultural Research and Development Fund (BARD) .
Keywords
- Abiotic stress
- Cytokinin
- IPT
- Promoter dissection
- SARK
- Senescence