Читать книгу Nanotechnology in Plant Growth Promotion and Protection - Группа авторов - Страница 59

ZnO NPs affect the availability of secondary metabolites which play vital roles in biotic and abiotic stress tolerance, e.g. phenolic, anthocyanin, and flavonoids compounds. Application of ZnO NPs with MS media increase phenolics and flavonoids concentration in Lilium ledebourii (Chamani et al. 2015). For Lupine, seed priming with ZnO NPs reduced the negative effects of salinity stress (150 mM NaCl), increased plant biomass, phenol content, pigments (chlorophyll‐a, chlorophyll‐b, and carotenoid), and stimulated the production of antioxidant enzymes like superoxide dismutase, peroxidase, and ascorbate peroxidase (Latef et al. 2017). Also, Hussein and Abou‐Baker (2018) recorded that spraying of Zn NPs to cotton at 100–200 mg/L can decrease plants’ Na/Ca and K/Ca ratios, while increase Ca/(K + Na) ratio. Torabian et al. (2018) also reported that foliar spray application of ZnO NPs at 2000 mg/L promotes sunflowers growth under salt stress (100 mM NaCl) without adverse effects. Watson et al. (2015) grew wheat in acidic and alkaline soils with Zn NPs amendment and revealed the positive effects of Zn NPs on wheat growth in alkaline soil. Under drought stress, the application of ZnO could promote crop productivity through higher germination and production of vigorous seedlings. For example, under polyethylene glycol‐induced drought stress, the effects of ZnO treatment increased soybeans seeds germination percentage and rate over control (Sedghi et al. 2013). Dimkpa et al. (2020) reported under drought, facile coating of urea with low‐dose ZnO NPs reduced panicle initiation time by five days and increased grain yield. Besides, studies have also shown Zn NPs applied to soil or hydroponic system can reduce negative effects of heavy metals such as lead, cadmium, or arsenic (Wang et al. 2018; Sharifan et al. 2019; Faizan et al. 2020).