Assessing the Biofortification of Wheat Plants by Combining a Plant Growth-Promoting Rhizobacterium (PGPR) and Polymeric Fe-Nanoparticles: Allies or Enemies?

Abstract

Biofortification has been widely used to increase mineral nutrients in staple foods, such as wheat (Triticum aestivum). In this study, a new approach has been used by analyzing the effect of inoculation with a plant growth-promoting rhizobacterium (PGPR), namely, Bacillus aryabhattai RSO25 and the addition of 1% (v/v) of organometallic Fe-containing polymeric nanoparticles (FeNPs) alone and in combination. Previously, the minimal inhibitory concentration of FeNPs for the bacterium was determined in order not to inhibit bacterial growth. All treatments had minor effects on seed germination and plant survival. Considering the physiology of plants, several photosynthetic parameters were significantly improved in individual treatments with FeNPs or the bacterium, particularly the efficiency of the photosystem II and the electron transport rate, which is indicative of a better photosynthetic performance. However, at the end of the experiment, a significant effect on final plant growth was not observed in shoots or in roots. When using FeNPs alone, earlier spike outgrow was observed and the final number of spikes increased by 20%. Concerning biofortification, FeNPs increased the concentration of Fe in spikes by 35%. In fact, the total amount of Fe per plant base rose to 215% with regard to the control. Besides, several side effects, such as increased Ca and decreased Na and Zn in spikes, were observed. Furthermore, the treatment with only bacteria decreased Na and Fe accumulation in grains, indicating its inconvenience. On its side, the combined treatment led to intermediate Fe accumulation in spikes, since an antagonist effect between RSO25 and FeNPs was observed. For this reason, the combined treatment was discouraged. In conclusion, of the three treatments tested, FeNPs alone is recommended for achieving efficient Fe biofortification in wheat.

Unlocking the Potential of Nano-Enabled Precision Agriculture for Efficient and Sustainable Farming

“…and nano zeolite on maize [108]. Fe NPs were reported to impact the bacterial proliferation of Bacillus aryabhattai, a plant growth-promoting rhizobacterium [109]. Coinoculation of Mesorhizobium ciceri with helper bacteria, Bacillus subtilis, and Mo nanoparticles enhanced the symbiotic efficiency of ST282 [110].…”

Impact of Magnetite Nanoparticles Coated with Aspartic Acid on the Growth, Antioxidant Enzymes Activity and Chlorophyll Content of Maize

“…Being an important unit of the ecosystem, plants provide a potential carrier for the transport of magnetic nanoparticles into the environment, going as far as their bioaccumulation in the food chain [6]. In plants, iron plays an important role in the biosynthesis of chlorophylls, photosynthesis and the respiration processes [7]. As a result, magnetic nanoparticles have an important role in germination, efficient growth and increasing yield [8].…”

Combating iron and zinc malnutrition through mineral biofortification in maize through plant growth promoting Bacillus and Paenibacillus species

“…The role of microbial inoculants in enhancing maize growth and biofortification has already been described the microbial community does so through the degradation of organic matter and releasing entrapped nutrients which add up to the soil fertility status, and in turn, is responsible for improved plant growth ( McDonagh et al., 1993 ; Phoomthaisong et al., 2003 ; Zou et al., 2019 ). The microorganisms solubilize the mineral nutrients by releasing organic acids into the rhizosphere and reducing the microsite pH suitable for micronutrients availability (Fe and Zn) and bio-fortify maize ( Hussain et al., 2019 ; Merinero et al., 2022 ). Moreover, the increase in plant height, and shoot fresh and dry biomass of maize with inoculation of PGPR in the present study were at par with Khalid et al.…”