Changes in morphological traits, anatomical and molecular alterations caused by gamma‑rays and zinc oxide nanoparticles in spinach (Spinacia oleracea L.) plant

Abstract

Spinach seeds were irradiated with gamma-rays after that soaked in zinc oxide nanopar- ticles (ZnO–NPs) at 0.0, 50, 100 and 200 ppm for twenty-four hours at room temperature. Vegetative plant growth, photosynthetic pigments, and proline contents were investigated. Also, anatomical studies and the polymorphism by the SCoT technique were conducted. The present results revealed that the ger- mination percentage was at the maximum values for the treatment of 100 ppm ZnO–NPs (92%), followed by 100 ppm ZnO–NPs+60 Gy (90%). The applica- tion of ZnO–NPs resulted in an enhancement in the plant length. The maximum of chlorophylls and carotenoids content was recorded in the treatment, 100 ppm ZnO–NPs+60 Gy. Meanwhile, the irra- diation dose level (60 Gy) with all ZnO–NPs treat- ments increased proline content and reached its maxi- mum increase to 1.069 mg/g FW for the treatment 60 Gy combined with 200 ppm ZnO–NPs. Also, the anatomical studies declared that there were variations between the treatments; un-irradiated and irradiated combined with ZnO–NPs plants which reveal that the leave epidermal tissue increased with 200 ppm ZnO–NPs in both the upper and lower epidermis. While irradiated plants with 60 Gy combined with 100 ppm ZnO–NPs gave more thickness of upper epi- dermis. As well as SCoT molecular marker technique efectively induced molecular alterations between the treatments. Where, SCoT primers targeted many new and missing amplicons that are expected to be associ- ated with the lowly and highly expressed genes with 18.2 and 81.8%, respectively. Also, showed that the soaking in ZnO-NPs was helped for reducing molecu- lar alteration rate, both spontaneous and induced by gamma irradiation. This nominates ZnO–NPs as potential nano-protective agents that can reduce irra- diation-induced genetic damage.