Nanoparticle-mediated amelioration of drought stress in plants: a systematic review

Abstract

Drought stress remains one of the most detrimental environmental constraints that hampers plant growth and development resulting in reduced yield and leading to economic losses. Studies have highlighted the beneficial role of carbon-based nanomaterials (NMs) such as multiwalled carbon nanotubes (MWNTs), single-walled carbon nanotubes (SWNTs), graphene, fullerene, and metal-based nanoparticles (NPs) (Ag, Au, Cu, Fe2O3, TiO2, and ZnO) in plants under unfavorable conditions such as drought. NPs help plants cope with drought by improving plant growth indices and enhancing biomass. It improves water and nutrient uptake and utilization. It helps retain water by altering the cell walls and regulating stomatal closure. The photosynthetic parameters in NP-treated plants reportedly improved with the increase in pigment content and rate of photosynthesis. Due to NP exposure, the activation of enzymatic and nonenzymatic antioxidants has reportedly improved. These antioxidants play a significant role in the defense system against stress. Studies have reported the accumulation of osmolytes and secondary metabolites. Osmolytes scavenge reactive oxygen species, which can cause oxidative stress in plants. Secondary metabolites are involved in the water retention process, thus improving plant coping strategies with stress. The deleterious effects of drought stress are alleviated by reducing malondialdehyde resulting from lipid peroxidation. Reactive oxygen species accumulation is also controlled with NP treatment. Furthermore, NPs have been reported to regulate the expression of drought-responsive genes and the biosynthesis of phytohormones such as abscisic acid, auxin, gibberellin, and cytokinin, which help plants defend against drought stress. This study reviewed 72 journal articles from 192 Google Scholar, ScienceDirect, and PubMed papers. In this review, we have discussed the impact of NP treatment on morphological, physio-biochemical, and molecular responses in monocot and dicot plants under drought conditions with an emphasis on NP uptake, transportation, and localization.

Assessment of Various Nanoprimings for Boosting Pea Germination and Early Growth in Both Optimal and Drought-Stressed Environments

“…Moreover, all of the NP treatments that were assessed in drought-stressed conditions showed an increase in biomass accumulation, whereas, in comparison to the control, the NP Ultra treatment proved to be the most effective. In this regard, similar findings have been reported in soybean research, where it was found that Fe, Cu, Co, and ZnO NP may increase plant tolerance to drought stress by promoting the expression of drought-related genes, such as GmWRKY27 , GmMYB118 , and GmMYB174 , involved in cell growth [ 83 , 84 ]. Cobalt is an essential nutrient for legumes since it is required for leghemoglobin synthesis and, thus, symbiotic nitrogen fixation.…”

The biochemical and growth-associated traits of basil (Ocimum basilicum L.) affected by silver nanoparticles and silver

“…Key factors influencing the extent of these changes include the chemical composition, size, concentration, surface coating, reactivity of the nanoparticles, treatment duration, application method, and the type of plant species or cultivar [ 7 , 36 , 37 ]. Growth parameters and content of photosynthetic pigments provide insight into how plants react to stress caused by nanoparticles [ 38 , 39 ]. Al-Huqail et al [ 40 ] found that silver nanoparticles have the potential to inhibit chlorophyll production in leaves, consequently impacting a plant's photosynthetic capabilities.…”

Synergistic interactions of nanoparticles and plant growth promoting rhizobacteria enhancing soil-plant systems: a multigenerational perspective

“…(2021) ; Alharbi et al. (2023) and Chandrashekar et al. (2023) , PGPR with NPs increased the relative water content, stomatal conductance, chlorophyll, and carotenoids in plants.…”