Titanium and Zinc Based Nanomaterials in Agriculture: A Promising Approach to Deal with (A)biotic Stresses?

Abstract

Abiotic stresses, such as those induced by climatic factors or contaminants, and biotic stresses prompted by phytopathogens and pests inflict tremendous losses in agriculture and are major threats to worldwide food security. In addition, climate changes will exacerbate these factors as well as their negative impact on crops. Drought, salinity, heavy metals, pesticides, and drugs are major environmental problems that need deep attention, and effective and sustainable strategies to mitigate their effects on the environment need to be developed. Besides, sustainable solutions for agrocontrol must be developed as alternatives to conventional agrochemicals. In this sense, nanotechnology offers promising solutions to mitigate environmental stress effects on plants, increasing plant tolerance to the stressor, for the remediation of environmental contaminants, and to protect plants against pathogens. In this review, nano-sized TiO2 (nTiO2) and ZnO (nZnO) are scrutinized, and their potential to ameliorate drought, salinity, and xenobiotics effects in plants are emphasized, in addition to their antimicrobial potential for plant disease management. Understanding the level of stress alleviation in plants by these nanomaterials (NM) and relating them with the application conditions/methods is imperative to define the most sustainable and effective approaches to be adopted. Although broad-spectrum reviews exist, this article provides focused information on nTiO2 and nZnO for improving our understanding of the ameliorative potential that these NM show, addressing the gaps in the literature.

Titanium nanoparticles activate a transcriptional response in Arabidopsis that enhances tolerance to low phosphate, osmotic stress and pathogen infection

“…Two of the most common effects of Ti application on several plant species are enhanced photosynthesis and increased nutrient uptake. These effects could be the primary origin of all other benefits of Ti such as augmented crop productivity, fruit quality, and improve tolerance to biotic and abiotic stresses, such as resistance to fungal pathogens ( Jajor et al., 2021 ; Satti et al., 2021 ) and to osmotic stresses ( Yin et al., 2020 ; Silva et al., 2022 ). It has been proposed that enhanced photosynthesis could be due to Ti promoting electron transport rate in the chloroplast by increasing the Hill reaction ( Hong et al., 2005 ).…”

“…These compounds are known to increase nutrient availability in the soil (e.g., P and Fe) and facilitate their uptake by the plant ( Gerke, 1993 ; Hocking, 2001 ; Jones et al., 2003 ). More recently, Ti has been found to improve plant tolerance to multiple fungal pathogens ( Jajor et al., 2021 ; Satti et al., 2021 ) and to protect plants from high salinity and drought stresses ( Silva et al., 2022 ). Despite the increasing use of Ti in agriculture ( Faraz et al., 2020 ), the molecular mechanisms behind the beneficial effects of Ti on plant growth and productivity are still poorly understood.…”

The role of nanoparticles in plant biochemical, physiological, and molecular responses under drought stress: A review

“…The application of NPs (TiO 2 ) increases light-induced water hydrolyzation into oxygen, electrons, and protons ( Silva et al., 2022 ), which ensures the entry of electrons and protons into the electron transport chain and results in a considerable increase in plant photosynthetic efficiency ( Alabdallah et al., 2021 ). In addition, NPs (TiO 2 ) also improve the expression of genes (LHCII-b) in the thylakoid membrane, which promotes light absorption in cell chloroplast ( Figure 2 ) ( Ze et al., 2011 ).…”

“…NPs modulate the accumulation of osmolytes and hormones that reduce oxidative stress by strengthening antioxidant machinery ( Silva et al., 2022 ). Proline accumulation improves plant – water status, stabilizes proteins, DNA, enzymes, and cellular membranes, and scavenges the ROS, protecting plants from drought-induced oxidative damage ( Farooq et al., 2017 ).…”

Mushroom-Derived Novel Selenium Nanocomposites’ Effects on Potato Plant Growth and Tuber Germination

“…The most promising applications of myco-synthesized nanomaterials in agriculture include, among others, the development of nano-formulations for crop yield improvement and for control of phytopathogenic infections [ 21 ]. Bulky doses of agrochemicals are required by conventional agricultural processes, adversely affecting ecosystems.…”