Lanthanum Silicate Nanomaterials Enhance Sheath Blight Resistance in Rice: Mechanisms of Action and Soil Health Evaluation

Abstract

In the current study, foliar spray with lanthanum (La) based nanomaterials (La10Si6O27 nanorods, La10Si6O27 nanoparticle, La­(OH)3 nanorods, and La2O3 nanoparticle) suppressed the occurrence of sheath blight (Rhizoctonia solani) in rice. The beneficial effects were morphology-, composition-, and concentration-dependent. Foliar application of La10Si6O27 nanorods (100 mg/L) yielded the greatest disease suppression, significantly decreasing the disease severity by 62.4% compared with infected controls; this level of control was 2.7-fold greater than the commercially available pesticide (Thifluzamide). The order of efficacy was as follows: La10Si6O27 nanorods > La10Si6O27 nanoparticle > La­(OH)3 nanorods > La2O3 nanoparticle. Mechanistically, (1) La10Si6O27 nanorods had greater bioavailability, slower dissolution, and simultaneous Si nutrient benefits; (2) transcriptomic and metabolomic analyses revealed that La10Si6O27 nanorods simultaneously strengthened rice systemic acquired resistance, physical barrier formation, and antioxidative systems. Additionally, La10Si6O27 nanorods improved rice yield by 35.4% and promoted the nutritional quality of the seeds as compared with the Thifluzamide treatment. A two-year La10Si6O27 nanorod exposure had no effect on soil health based on the evaluated chemical, physical, and biological soil properties. These findings demonstrate that La based nanomaterials can serve as an effective and sustainable strategy to safeguard crops and highlight the importance of nanomaterial composition and morphology in terms of optimizing benefit.

Selenium Nanomaterials Enhance Sheath Blight Resistance and Nutritional Quality of Rice: Mechanisms of Action and Human Health Benefit

“…The content of apigenin, galangin, naringenin, sakuranetin, and chlorogenic acid was significantly increased by the application of Se 0 NMs compared to infected controls (Figure F). These flavonoids can act as allelochemicals and antioxidants to alleviate the severity of ShB damage in rice . The above findings clearly demonstrate that the application of Se 0 NMs activated the JA, SA, and flavonoid synthesis pathways, with a subsequent increased content of these important biomolecules in rice tissues.…”

“…Dose is clearly an important factor for ShB control by Se 0 NMs as disease severity with 10 and 20 mg/L was significantly greater than that with 5 mg/L. This appears to be due to a Se 0 NM dose-dependent triggering of the plant’s antioxidative system imbalance, which induced phytotoxicity. , Rice growth parameters in response to different concentrations of foliar-applied S 0 and La-based NMs also exhibited a trend of “low promoting and high inhibiting.” , Overt leaf and stem damage was also evident after the foliar application of 20 mg/L Se 0 NMs (Figure S2). Thakur et al demonstrated that foliar application with 2 g/L Ag 0 NMs decreased the incidence of ShB in rice by 28.1% compared with infected control .…”

“…MDA content in fresh rice leaves was measured as previously described . The activity of CAT, POD, and SOD in rice shoots was performed as described separately, with slight modifications . The activity of GPX was measured by using a cellular glutathione peroxidase assay kit with DTNB (Beyotime, China).…”

“…Plants have evolved a series of disease resistance strategies, including systemic acquired resistance (SAR), antioxidative systems, and flavonoid biosynthesis pathways to respond to pathogen infection. , Disease resistance enhancement has been considered as an effective and sustainable approach to suppress crop disease, particularly when compared with application of environmentally problematic pesticides. , Selenium (Se), a trace and metalloid element, at specific doses has been shown to have beneficial effects on the growth and disease resistance of crops by promoting photosynthesis and enhancing the antioxidative ability . For example, the foliar application of Na 2 SeO 3 at 790 μg/L significantly enhanced the photosynthesis of radish, increasing growth by 30.7% .…”

Salinity-Driven Interface Self-Assembly of a Biological Amphiphilic Emulsifier to Form Stable Janus Core–Shell Emulsion for Enhancing Agrichemical Delivery

“…Moreover, inorganic salts lead to increased destabilization of aqueous emulsions , and enhance the degree of soil hardening due to agrichemical loss to the ecological environment. Meanwhile, the environment, especially the soil, is endangered owing to the loss of numerous and excessive use of pesticides. , Therefore, agrichemical salinity hazards must be urgently addressed to improve and achieve sustainable agrichemical utilization and to reduce environmental pollution.…”