Glycine betaine functionalized graphene oxide as a new engineering nanoparticle lessens salt stress impacts in sweet basil (Ocimum basilicum L.).

Regarding destructive impacts of salinity on different vital processes of plants, many strategies have been developed to alleviate salinity effects. Amongst, nanoparticles (NPs) application has been achieved great attention. For that point, considering positive effects of graphene oxide NPs (GO) and glycine betaine (GB) on different plant processes, GO-GB NPs were primarily synthesized to use GO as a carrier for GB. Then, GO, GB and GO-GB (each in three concentrations; 0, 50 and 100 mg L-1) were applied on sweet basil (Ocimum basilicum L.) plants under 0, 50 and 100 mM salinity stress conditions. The results demonstrated that GO-GB NPs could lessen negative effects of salinity by enhancing agronomic traits, photosynthetic pigments, chlorophyll fluorescence parameters, membrane stability index (MSI), proline, phenols, antioxidant enzymes activities and dominant constituents of essential oils and decreasing MDA and H2O2. These positive effects were more considerable at its lower dose (50 mg L-1) introducing it as the best treatment to ameliorate sweet basil performance especially essential oil compounds under salt stress. GO application at its higher dose (100 mg L-1) demonstrated toxicity by negative impacts on the measured parameters. In conclusion, the positive response of sweet basil to GO-GB NPs under non-stress and salt stress conditions cause to consider the NPs as potential novel plant growth promoting and stress protecting agent with innovative outlooks for its use in agriculture.