Both strigolactones (SLs) and abscisic acid (ABA) biosynthetically originate from carotenoids. Considering their common origin, the interaction of these two hormones at the biosynthetic and/or regulatory level may be anticipated. Here, we show in rice that drought simultaneously induces SL production in the root, and ABA production and the expression of SL biosynthetic genes in the shoot. Under control conditions, the ABA concentration was higher in shoots of the SL biosynthetic rice mutants dwarf10 (d10) and d17 than in wild-type plants, while a similar trend was observed for SL-perception mutant d3. These differences were enhanced under drought. However, drought did not result in an increase in leaf ABA content in rice mutant line d27, carrying a mutation in the gene encoding the first committed enzyme in SL biosynthesis, to the same extent as in the other SL mutants and the wild-type. Accordingly, d10, d17 and d3 lines were more drought tolerant than wild-type plants, whereas d27 displayed decreased tolerance. Finally, over-expression of OsD27 in rice resulted in increased levels of ABA when compared with wild-type plants. We conclude that the SL and ABA pathways are connected with each other through D27, which is playing a crucial role in determining ABA and SL content in rice.
|Original language||English (US)|
|Number of pages||12|
|Journal||Journal of Experimental Botany|
|State||Published - Mar 10 2018|
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: We thank Prof. J. Li and prof. Y. Wang for kindly providing the rice OsD27 over-expression lines. We thank Francel Verstappen for his technical support at WUR in the Netherlands. This work was supported by the Higher Education Commission (HEC) of Pakistan to IH, Netherlands Organization for Scientific Research (NWO; Equipment grant, 834.08.001 to HJB) and King Abdullah University of Science and Technology (KAUST) and the EU (METAPRO; FP7 KBBE- 2009-3-1-01). We acknowledge a private donor who supported BAJ’s work via the Wageningen University Fund.