Fluoride, a highly phytotoxic and nonessential element in higher concentrations is a major concern in decreasing wheat production. In the present study, we examined the ability of silicon, a semi-essential element which helps to mitigate the detrimental effects of various environmental stresses in overcoming fluoride-mediated toxicity in wheat cultivars. The seeds of two wheat cultivars, tolerant (Raj 4120) and susceptible (Raj 4238), were grown in soil supplemented with NaF (0, 400, and 500 mg kg-1) and then supplied with silicon (0, 200, and 300 mg kg-1) as Na2SiO3 at 10th days of germination with 160 mu mol quanta m-2 s-1 of photon density, 16-h photoperiod, and 55-60% relative humidity at 25 +/- 2 degrees C. The fluoride stress led to oxidative damage in roots, as evidenced by the significant elevation in MDA and H2O2 content in both wheat cultivars and decreased major components of the suberin and cesA4 gene expression in roots, which together can negatively impact the rigidity and strength of the cell wall. Conversely, the application of silicon had a beneficial effect in both wheat cultivars with and without fluoride stress. Silicon decreased the MDA and H2O2 content levels and increased the antioxidant defence system. Interestingly, Si was able to partially reverse F stress in both the wheat cultivars by increasing suberin deposition on the endodermis and promoting secondary cell wall synthesis gene expression in roots. The present study concluded that soil application of silicon can be a useful approach in protecting wheat from fluoride toxicity.

来源平台：JOURNAL OF PLANT GROWTH REGULATION