Ameliorating Drought Effects in Wheat Using an Exclusive or Co-Applied Rhizobacteria and ZnO Nanoparticles

Abstract

Drought is a major abiotic factor and affects cereal-based staple food production and reliability in developing countries such as Pakistan. To ensure a sustainable and consistent food supply, holistic production plans involving the integration of several drought mitigation approaches are required. Using a randomized complete block design strategy, we examined the drought-ameliorating characteristics of plant growth-promoting rhizobacteria (PGPR) and nanoparticles (NPs) exclusively or as a combined application (T4) through three stages (D1, D2, and D3) of wheat growth (T1, control). Our field research revealed that Azospirillum brasilense alone (T2) and zinc oxide NPs (T3) improved wheat plant water relations, chlorophyll, proline, phenolics and grain quality, yield, and their allied traits over the stressed treatments. Specifically, the best outcome was observed in the combined treatment of PGPR and ZnO NPs (T4). Interestingly, the combined treatment delivered effective drought mitigation through enhanced levels of antioxidants (15% APX, 27% POD, 35% CAT, 38% PPO and 44% SOD) over controls at the grain-filling stage (GFS, D3 × T1). The 40% improvements were recorded under the combined treatment at GFS over their respective controls. Their combined usage (PGPR and ZnO NPs) was concluded as an effective strategy for building wheat resilience under drought, especially in arid and semi-arid localities.

Appropriate Application Methods for Salicylic Acid and Plant Nutrients Combinations to Promote Morpho-Physiological Traits, Production, and Water Use Efficiency of Wheat under Normal and Deficit Irrigation in an Arid Climate

“…In addition, water deficit is considered a predominant factor, causing a significant yield loss of the wheat crop due to its negative effects on several morpho-physiological traits during their critical growth stages [ 6 ]. It was reported that the exposure of wheat plants to deficit water stress at the tillering stage results in a significant reduction in plant height, tiller number, spiked tillers, leaf area, photosynthesis activity, chlorophyll content, several metabolic processes, and relative water content (RWC), which eventually leads to a sharp decrease in plant biomass [ 7 , 8 ]. The flowering and grain-filling stages are considered the most sensitive stages to water deficit stress in wheat.…”

“…Among the strategies associated with the introduction of tolerance toward water deficit stress is the exogenous application of macronutrients and micronutrients, as well as compatible solute compounds, such as salicylic acid. In general, previous studies highlighted that the exogenous application of these materials is considered a cost-effective and efficient option to alleviate the harmful effects of abiotic stress on the growth and production of crop plants [ 7 , 8 , 11 ].…”

Synergistic impact of nanomaterials and plant probiotics in agriculture: A tale of two-way strategy for long-term sustainability

“…This, in turn, modulates different biochemical and molecular signal transducing pathways, resulting in improved signal perception and, as a result, increased growth and yield potential ( Bhatt et al, 2020 ). However, recent evidence suggests that the coupling effect of plant probiotics (PPs) and NMs may play an excellent role in managing abiotic stress ( Azmat et al, 2022 ; Muhammad et al, 2022 ; Alharbi et al, 2022a , b ). The combo effect of NMs and PPs exhibits various stress ameliorating effects by improving levels of photosynthetic pigments, activities of antioxidant enzymes, total soluble sugars, and reducing stress markers such as MDA content and electrolytic leakage in plants under salt stress ( Yasmin et al, 2021 ; Alharbi et al, 2022a ) and drought stress ( Akhtar et al, 2021 ; Azmat et al, 2022 ).…”

Melatonin: Current status and future perspectives in horticultural plants

“…worldwide. Horticultural crops are very vulnerable to drought stress (Gao et al, 2022;Muhammad et al, 2022;Toscano et al, 2023). Drought stress is reported to cause abnormalities in the physiological and morphological states of plants (Hanaka et al, 2021).…”

“…Global climate change has intensified drought stress episodes, which are emerging as a serious threat to crop growth and productivity worldwide. Horticultural crops are very vulnerable to drought stress ( Gao et al., 2022 ; Muhammad et al., 2022 ; Toscano et al., 2023 ). Drought stress is reported to cause abnormalities in the physiological and morphological states of plants ( Hanaka et al., 2021 ).…”