IMPACT OF ZINC OXIDE (ZnO) NANOPARTICLES ON THE GROWTH, PHYSIOLOGY, YIELD AND BIOCHEMICAL TRAITS OF WHEAT (Triticum aestivum L.) UNDER SALT STRESS

Abstract

Worldwide, the productivity of various cereal crops is adversely affected by potential threat, with salinity stress being a significant factor. To alleviate the negative effects of salt stress on plants, a promising strategy is the application of ZnO nanoparticles through spraying. Although their effectiveness has been noted, the specific mechanism by which nano-ZnO particles operate to counter salt stress is not yet fully understood. Concerning this issue, a pot experiment was carried out at the Net house, Department of Agronomy, Hajee Mohammad Danesh Science and Technology University (HSTU), Dinajpur, Bangladesh during November 2022 to March 2023. The experiment encompassed three tiers of salt stress (0, 100, and 150 mM NaCl stress) and three levels of ZnO (0, 150, and 300 µM), resulting in nine distinct treatments, namely: i) S0ZnO0 (0 mM NaCl + 0 µM ZnO), ii) S0ZnO1(0 mM NaCl + 150 µM ZnO), iii) S0ZnO2 (0 mM NaCl +300 µM ZnO), iv) S1ZnO0 (100 mM NaCl + 0 µM ZnO), v) S1ZnO1 (100 mM NaCl + 150 µM ZnO), vi) S1ZnO2 (100 mM NaCl + 300 µM ZnO), vii) S2ZnO0 (150 mM NaCl + 0 µM ZnO), viii) S2ZnO1 (150 mM NaCl + 150 µM ZnO), ix) S2ZnO2 (150 mM NaCl + 300 µM ZnO). The main findings showed that the studied parameters such plant morphology (plant height, number of leaves, leaf area), growth (fresh & dry weight of leaves, stems and roots), phenology (days to booting, heading, anthesis and physiological maturity), physiology (photosynthetic pigments; water status-RWC, WSD, WRC, WUC; MSI), yield contributing traits (spike length, number of spikelets spike-1, grains spike-1, and hundred grains weight), yield indices (grain, straw and biological yield, and harvest index) and biochemical traits were negatively and progressively affected with increasing salt stress. Following the application of nano-ZnO particles, enhancements were observed in the aforementioned plant traits. Notably, ZnO2 (300 µM ZnO) demonstrated the most favorable results, although its performance was nearly statistically indistinguishable from ZnO1 (150 µM ZnO). Furthermore, the results showed that although SS raised the Na content while lowering the K, Ca, N, and protein content, ZnO administration increased the K, Ca, N, and protein values while falling the Na values. The application of nano-Zn particles has demonstrated the potential to enhance plant development by alleviating salt stress, with 150 µM ZnO identified as an effective dosage.