Nanobiostimulant action of trigolic formulated zinc sulfide nanoparticles (ZnS-T NPs) on rice seeds by triggering antioxidant defense network and plant growth specific transcription factors.

Under a changing climate, nanotechnological interventions for climate resilience in crops are critical to maintaining food security. Prior research has documented the affirmative response of nano zinc sulfide (nZnS) on physiological traits of fungal-infested rice seeds. Here, we propose an application of trigolic formulated zinc sulfide nanoparticles (ZnS-T NPs) on rice seeds as nanobiostimulant to improve physiological parameters by triggering antioxidative defense system, whose mechanism was investigated at transcriptional level by differential expression of genes in germinated seedlings. Nanopriming of healthy rice seeds with ZnS-T NPs (50 µg/ml), considerably intensified the seed vitality factors, including germination percentage, seedling length, dry weight and overall vigor index. Differential activation of antioxidant enzymes, viz. SOD (35.47%), APX (33.80%) and CAT (45.94%), in ZnS-T NPs treated seedlings reduced the probability of redox imbalance and promoted the vitality of rice seedlings. In gene expression profiling by reverse transcription quantitative real time PCR (qRT-PCR), the notable up-regulation of target antioxidant genes (CuZn SOD, APX and CAT) and plant growth specific genes (CKX and GRF) in ZnS-T NPs treated rice seedlings substantiates their molecular role in stimulating both antioxidant defenses and plant growth mechanisms. The improved physiological quality parameters of ZnS-T NPs treated rice seeds under pot house conditions corresponded well with in vitro findings, which validated the beneficial boosted impact of ZnS-T NPs on rice seed development. Inclusively, the study on ZnS-T NPs offers fresh perspectives into biochemical and molecular reactions of rice, potentially positioning them as nanobiostimulant capable of eliciting broad-spectrum immune and growth-enhancing responses.

Sustained release of Zn from zinc sulfide nanoparticles (ZnS NPs) amplified the bioaccessibility of Zn in soil: Adsorption dynamics and dissolution kinetics.

Controlled-release micronutrient supplementation to provide better bioavailable zinc (Zn) under alkaline soil conditions is a concept of commercial pertinence for sustainable agriculture. High pH stable nano-scaled ZnS is the material under study in the present investigation where the adsorption dynamics and dissolution kinetics of sono-chemically synthesized zinc sulfide nanoparticles (ZnS NPs) were evaluated in comparison to ZnSO4 in Lufa 2.2 soil for supplementation of Zn. The mechanism of adsorption of ZnS NPs and ZnSO4 onto Lufa 2.2 soil was well explained by fitting into the Freundlich adsorption model and pseudo-second order equation. ZnS NPs reflected the stronger ability to get adsorbed on the Lufa 2.2 soil as compared to metal ions, due to higher surface reactivity of NPs and higher Kf value (0.557) than ZnSO4 (0.463). Time relevant enhancement in extractability of Zn from ZnS NPs amended soil and diminution in extractability of Zn from ZnSO4 spiked soil was observed in bioavailability studies. The increased labile pool of Zn from ZnS NPs amended soil over time was due to their slow dissolution in soil and could be adjusted to consider as "sustained released ZnS NPs". Dissolution of ZnS nanoparticles (NPs) in Lufa 2.2 soil adhered to the first-order extraction model, exhibiting extended half-lives of 27.72 days (low dose) and 28.87 days (high dose). This supported prolonged stability, increased reactivity, and reduced ecological risk compared to conventional Zn salt fertilizers, promoting enhanced crop productivity.

First report on larvicidal potential of zinc sulfide aqua nanoparticles against Aedes aegypti (Linnaeus).

BACKGROUND & OBJECTIVES: Mosquitoes are considered to be the deadliest arthropod-vectors, which cause millions of human deaths globally. Presently, nanotechnology in the field of insect pest management is being explored. The current study deals with the synthesis of zinc sulfide nanoparticles (ZnS NPs) in aqueous medium and their larvicidal efficacy against Ae. aegypti. METHODS: Aqueous zinc sulfide nanoparticles were synthesized by mixing equal quantities of zinc acetate and zinc sulfide solutions by using sonochemical irradiation method. The synthesized NPs were characterized by Transmission Electron Microscopy (TEM). Larvicidal activity was performed according to WHO protocol and toxicity values were calculated by log-probit technique using POLO software. The morphological alterations between treated and control larvae were observed and compared. RESULTS: TEM studies revealed the average particle size of synthesized nanoparticles to be 19.65 ± 1.08 nm with distorted spherical shape. The mosquito-larvicidal efficacy of ZnS NPs against Ae. aegypti showed maximum lethal effects with the LC50 and LC90 values of 4.49 and 15.58 ppm respectively. The morphological analysis of the mosquito larvae treated with ZnS NPs revealed shrunken and darkened body. INTERPRETATION & CONCLUSION: This study suggests that synthesized zinc sulfide aqua nanoparticles have good potential larvicidal properties making them best candidate for Aedes aegypti control.

Nano-sulfides of Fe and Mn Efficiently Augmented the Growth, Antioxidant Defense System, and Metal Assimilation in Rice Seedlings.

Physiological and biochemical mechanisms behind nanoparticle (NP)-induced seed germination by nanopriming with metal sulfide NPs are lacunae in the field of agriculture. Sonochemically synthesized aqua-dispersed ferrous sulfide NPs (FeS-NPs) and manganese sulfide NPs (MnS-NPs) were examined as nanopriming agents for physiological, pathological, and antioxidative defense parameters of rice in the present study. Under pot house conditions, in vivo nanopriming of rice seeds with FeS NPs and MnS-NPs at a concentration of 35 µg/mL for 8 h significantly improved the physiological parameters, viz., germination percentage, seed germination index, mean germination time, dry weight, and vigor index, and decreased the phytopathological parameters of nanoprimed rice seeds, viz., mortality, seed rot, and seedling blight. Stimulation of superoxide dismutase (SOD ≥ 28.16%), ascorbate peroxidase (APX ≥ 52.38%), and catalase (CAT ≥ 28.57%) enzymes in FeS-NP- and MnS-NP-nanoprimed seeds as compared to control (hydroprimed seeds) enhanced the fitness of rice seedlings. The augmented levels of Fe and Mn content in the shoots and roots of NP-treated seedlings as compared to hydroprimed seedlings confirmed the incorporation nanometals in rice seedlings as nanonutrients for effective plant growth. Inclusively, FeS-NPs and MnS-NPs were shown to be effective nanopriming agents for promoting the germination of naturally fungal infested rice seeds.

Nanomaterized zinc sulfide-meerschaum biomatrix efficiently suppressed Fusarium verticilloides with augmented rice seed quality benefits during storage.

BACKGROUND: The seed-borne mycopathogen Fusarium verticilliodes is a serious and deleterious pathogen causing substantial losses of rice seeds and grains. Rice seeds are prone to infestation at all points of the production chain and the fungal pathogen continues dormant devastation even during storage, adversely affecting the seed parameters. Its control is compromised due to the nonavailability of recommended fungicides during storage. Nanotechnological interventions can provide effective and ecofriendly alternative against mycopathogens during resting periods. Herein, the zinc sulfide-meerschaum nano bio-matrix (nZnS-MR) is presented to show this strategy, which worked well against F. verticilliodes when applied on freshly harvested rice seeds during 6 months of storage. RESULTS: The healthy, smooth and rounded girths of F. verticilloides mycelium were reduced with loss of turgidity, disrupting the hyphal exterior architecture, during in vitro treatment with nZnS-MR, endorsed by staining methodology, crystal violet and intracellular soluble protein leakage assays. In vivo application on rice seeds optimized 750 µg g-1 of nano zinc sulfide (nZnS) for 6 months of application during storage with maximum reduction of disease parameters [seedling blight (1.19%) and seed rot (5.43%)] and most augmented quality parameters [maximum germination (94.14%), seedling length (22.50 cm), dry weight (0.121 g) and vigor index (11.37)]. nZnS-MR acted as a slow release nanoformulation of nZnS for long-term antifungal activity. CONCLUSION: nZnS-MR is presented as an ecofriendly, biocompatible, bio-efficient, profertilization, cost-effective green material for the control of F. verticilliodes with rice seed invigorating effect, describing it as new a nano-generation material for efficient storage application.

Cyclo(l-proline-l-serine) Dipeptide Suppresses Seed Borne Fungal Pathogens of Rice: Altered Cellular Membrane Integrity of Fungal Hyphae and Seed Quality Benefits.

Five proline-containing diketopiperazines (Pro-DKPs) produced by antagonistic microorganisms as secondary metabolites were selected and synthesized under laboratory conditions. Out of five synthesized Pro-DKPs, cyclo(l-Pro-l-Ser) (DKP-6) revealed the best inhibition of fungal pathogens (Fusarium verticillioides and Fusarium fujikuroi) of rice under in vitro conditions with effective doses lower than standard fungicide carbendazim. DKP-6 induced stress on the fungal cell membrane integrity, which was revealed by calcofluor white and propidium iodide assays, endorsed by ultra-microscopic details and soluble protein leakage assays. In vivo seed treatment of infested rice seeds with DKP-6 at 2000 µg/mL for 10 h of seed treatment inflicted best reduction in seed rot and seedling blight with respect to control and carbendazim. Significant enhancement in seedling quality parameters were also observed. The work presented the strong influence of cyclo(l-Pro-l-Ser) as a mycocidal seed treatment agent better than synthetic toxic fungicides for rice.

Impact of Synthesis Methods on Structural and Antifungal Properties of Metal Sulfide Nanoparticles.

Nanotechnology has the ability to produce novel nano-sized materials with excellent physical and chemical properties to act against phytopathogenic diseases, essential for revolution of agriculture and food industry. The development of facile, reliable and eco-friendly processes for the synthesis of biologically active nanomaterials is an important aspect of nanotechnology. In the present paper, we attempted to compare sonochemical and co-precipitation method for the synthesis of metal sulfide nanoparticles (MS-NPs) for their structural and antifungal properties against various phytopathogenic fungi of rice. The preparation of nanospheres (NSs) and nano rods (NRs) of CuS, FeS and MnS was monitored by UV-Visible spectroscopy complemented by transmission electron microscope (TEM), scanning electron microscope (SEM), atomic force microscopy (AFM), dynamic light scattering (DLS) and Zeta potential analyser. Sonochemical method resulted in formation of spherical shaped nanoparticles of size (7-120 nm), smaller than those of nanorods (50-200 nm) prepared by co-precipitation produced. It was observed that the metal sulfide nanospheres exhibited a better antifungal potential against D. oryzae, C. lunata and S. oryzae as compared to rod shaped metal sulfide nanoparticles. Smaller size and large surface area of spherical shaped particles opens up an important perspective of the prepared MS-NPs.

Development of MgO-sepoilite Nanocomposites against Phytopathogenic Fungi of Rice (Oryzae sativa): A Green Approach.

Innovation in agriculture is a vital organ of research for sustainable food supply to the increasing global population. Organic compounds used as fungicidal agents against seed-borne pathogens are bracketed due to their toxic nature and residual effects, which are either already banned or may get banned in the near future. In this study, the surface and electric properties of nontoxic sepiolite have been blended with the antimicrobial properties of metabolizable MgO nanoforms (nMgO) as a greener alternative to prepare their nanocomposites. We compared a sepiolite-MgO (SE-MgO) nanocomposite with MgO nanoparticles in an aqua dispersed form (aqMgO-NPs) for their antifungal evaluation against various phytopathogenic fungi of rice. The SE-MgO nanocomposite was more potent in comparison to aqMgO-NPs with ED90 > 230 and 249 µg/mL, respectively, against the test fungi better than standard fungicides. Ultramicroscopic studies revealed hyphal distortion and spore collapse as the cause of antimycotic activity. The in vitro seed treatment revealed 100% hyphal reduction with SE-MgO at 250 µg/mL of MgO as an active ingredient (a.i.). MgO and sepiolite both have been regarded as safe materials by international agencies; therefore, using their nanocomposites can be an effective, sustainable, nontoxic, eco-friendly, and residue-free strategy for combating fungal menace against phytopathogens.