Nitric oxide acts downstream of abscisic acid in molybdenum-induced oxidative tolerance in wheat
Our study first reveals that Mo mediates oxidative tolerance through ABA signaling. Moreover, NO acts downstream of ABA signaling in Mo-induced oxidative tolerance in wheat under drought stress.
Nitric oxide (NO) is related to the improvement of molybdenum (Mo)-induced oxidative tolerance. While the function of Mo in abscisic acid (ABA) synthesis and in mediating oxidative tolerance by the interaction of ABA and NO remain to be studied. The –Mo and +Mo treatment-cultivated wheat was separated and subsequently was pretreated with AO inhibitor, ABA synthesis inhibitor, exogenous ABA, NO scavenger, NO donor or their combinations under polyethylene glycol 6000 (PEG)-stimulated drought stress (PSD). The AO activity and ABA content were increased by Mo in wheat under PSD, however, AO inhibitor decreased AO activity, correspondingly reduced ABA accumulation, suggesting that AO involves in the regulation of Mo-induced ABA synthesis. Mo enhanced activities and expressions of antioxidant enzyme, while these effects of Mo were reversed by AO inhibitor and ABA synthesis inhibitor due to the decrease of ABA content, but regained by exogenous ABA, indicating that Mo induces oxidative tolerance through ABA. Moreover, NO scavenger inhibited activities of antioxidant enzyme caused by Mo and exogenous ABA, but the inhibitions were eliminated by NO donor, indicating that NO is involved in ABA pathway in the regulation of Mo-induced oxidative tolerance in wheat under PSD. Finally, we proposed a scheme for the mechanism of Mo-induced oxidative tolerance.
KeywordsWinter wheat Molybdenum Drought stress Oxidative tolerance Aldehyde oxidase Abscisic acid Nitric oxide
This work was supported by the National Key Research and Development program of China (2016YFD0200108), the Fundamental National Key Project of Science and Technology (2014BAD14B02), the 948 Project from the Ministry of Agriculture of China (2016-X41) and the National Natural Science Foundation of China (Program No. 41771329).
XS, CH and SW conceived the experiment. SW, SX and YX performed the experiment. SW, QT and XZ analyzed the data. SW and XS wrote the manuscript.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
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