Physiological and Molecular Response of Wheat Cultivars to Titanium Dioxide or Zinc Oxide Nanoparticles under Water Stress Conditions

Abstract

A field trial was conducted through two successive winter seasons 2017/2018 and 2018/2019 to evaluate the influence of TiO2 or ZnO nanoparticles on two wheat cultivars (Gimeza 12 and Sids 13) under different water irrigation requirements of 100% (WW) and 75% (WS). The results showed that drought stress decreases morphological parameters, photosynthetic pigments, and wheat yield (ha−1). However, the total soluble sugars, total free amino acids, proline content, and water productivity were increased. Application of TiO2 or ZnO nanoparticles declines the negative influence of water deficit. Furthermore, SDS-PAGE revealed in Gimeza 12 treated with TiO2 or ZnO nanoparticles, it stimulates the appearance of some proteins at the MW of 28 kDa in WW and WS, while in WS, it records the new polypeptide at 18 kDa. Moreover, Gimeza 12 treated with nano-TiO2 led to the disappearance of two bands at 163 and 51 kDa in WS. However, for Sids13, there was no difference between the treatments in WW and WS except in nano-ZnO at WS that disappeared the polypeptides at MWs of 163, 51, and 18 kDa. Primer SRAP results showed that the plants treated with TiO2 or ZnO nanoparticles had a minor effect at the genomic DNA level, which was illustrated by the appearance or absence of some bands. Besides, the low concentrations of nanoparticles did not damage DNA. On the other hand, one negative marker of −233 bp disappeared in the Gimeza 12 cultivar treated with WS + nano-TiO2 and was revealed in the other treatments using primer SRAP-2. The results showed that the Gimeza 12 cultivar which had the highest grain yield was more tolerant to drought than the Sids 13 cultivar.