Zinc oxide nanoparticles mediated substantial physiological and molecular changes in tomato

Abstract

There has long been debate about how nanoproducts meet agricultural requirements. This study aimed to investigate tomato responses to the long-time foliar application of zinc oxide nanoparticles (ZnO-NP; 0 and 3 mgl-1) or bulk type (BZnO). Both ZnO-NP and BZnO treatments, especially the nanoform, were significantly capable of improving growth, biomass, and yield. The ZnO-NP treatment upregulated the expression of the R2R3MYB transcription factor by 2.6 folds. The BZnO and ZnO-NP treatments transcriptionally up-regulated WRKY1 gene by 2.5 and 6.4 folds, respectively. The bHLH gene was also upregulated in response to BZnO (2.3-fold) or ZnO-NP (4.7-fold). Moreover, the ZnO-NP application made a contribution to upregulation in the EREB gene whereas the bulk compound did not make a significant change. Upregulation in the HsfA1a gene also resulted from the ZnO-NP (2.8-fold) or BZnO (1.6-fold) supplementation. The MKK2 and CAT genes displayed a similar upregulation trend in response to the supplements by an average of 3-folds. While the application of ZnO-NP slightly down-regulated the histone deacetylases (HDA3) gene by 1.9-fold, indicating epigenetic modification. The supplements, especially the nano-product, enhanced concentrations of K, Fe, and Zn in both leaves and fruits. The concentrations of Chla, Chlb, and carotenoids were increased in response to the BZnO or ZnO-NP treatments. Likewise, BZnO or ZnO-NP mediated an increase in activity of nitrate reductase and proline content in leaves. These treatments increased soluble phenols and phenylalanine ammonia-lyase activity. With a similar trend, the BZnO or ZnO-NP application improved the activities of catalase and peroxidase enzymes. The reinforcement in metaxylem and secondary tissues resulted from the applied supplements. This study provides comprehensive comparative evidence on how ZnO-NPs may remodel the chromatin ultrastructure and transcription program, and confer stress tolerance in crops. This study also underlines the necessity of providing integrated transcriptome and proteome data in future studies.

The Multifaceted Roles of Proline in Cell Behavior

“…In plants, L-Pro is accumulated after exposure to heavy metals such as cadmium, chromium, and zinc (Sharma et al, 1998;Verbruggen and Hermans, 2008;Hayat et al, 2012;Dubey et al, 2018;Dong et al, 2021;Pejam et al, 2021;Zdunek-Zastocka et al, 2021), and this mitigates the detrimental effects of cadmium in young olive plants (Zouari et al, 2016) and cultured tobacco cells (Islam et al, 2009). Heavy metal toxicity is usually associated with ROS accumulation (Figure 4).…”

Bulk and nanoparticles of zinc oxide exerted their beneficial effects by conferring modifications in transcription factors, histone deacetylase, carbon and nitrogen assimilation, antioxidant biomarkers, and secondary metabolism in soybean

“…In alkaline soils, plants face reduced access to Zn, a limiting factor that restricts crop yields and reduces the quality of crop-derived foods. Zn deficiency in crops not only restricts their productivity but also influences human health [ 4 ]. Hence, attempts have been made to introduce the novel, safe, and high-potent Zn fertilizers to counteract with Zn crisis and fulfill the agricultural requirements [ 3 , 4 ].…”

“…Zn deficiency in crops not only restricts their productivity but also influences human health [ 4 ]. Hence, attempts have been made to introduce the novel, safe, and high-potent Zn fertilizers to counteract with Zn crisis and fulfill the agricultural requirements [ 3 , 4 ]. Taking sustainable agriculture into account, different modern technologies, in particular nanotechnology, offer novel strategies to meet the farmer’s expectations and the food demand of humans [ 3 , 4 ].…”

“…Hence, attempts have been made to introduce the novel, safe, and high-potent Zn fertilizers to counteract with Zn crisis and fulfill the agricultural requirements [ 3 , 4 ]. Taking sustainable agriculture into account, different modern technologies, in particular nanotechnology, offer novel strategies to meet the farmer’s expectations and the food demand of humans [ 3 , 4 ]. Nanotechnology paves the way for improving the efficiency of a vast array of commercial products such as fertilizers/pesticides in agriculture by exploitations of engineered nanoparticles (NPs), especially metal-based NPs.…”

“…Taking zinc oxide nanoparticles (ZnO NPs; one of the most commonly used NPs) into account, the application of these nanomaterials improved growth and productivity in plant species, like Datura stramonium [ 2 ], wheat [ 12 ], and soybean [ 13 ]. Moreover, its application enhanced the production of secondary metabolites, like essential oils in Feverfew [ 14 ], phenolics in Melissa officinalis [ 15 ], alkaloids in Datura stramonium [ 2 ], and phenylpropanoids in tomato [ 4 ]. Exposure to ZnO NPs also affected phytohormones [ 3 , 16 , 17 ].…”