Complete genome sequence of Bacillus subtilis NA05 (=NBRC 116153), a phosphate-solubilizing bacterium isolated from crop field soil.

We report the complete genome sequence of the phosphate-solubilizing bacterium Bacillus subtilis NA05 (=NBRC 116153), consisting of a circular chromosome of ~3.8 M bp and two circular plasmids. The data presented here provide further insight into the genetic and functional potential of B. subtilis and the mechanism of phosphate solubilization.

Exposure of cherry radish (Raphanus sativus L. var. Radculus Pers) to iron-based nanoparticles enhances its nutritional quality by trigging the essential elements.

Iron (Fe) deficiency is a pervasive nutritional disorder, and producing vegetables enriched with Fe as a dietary source is imperative. Herein, Fe3O4, FeO(OH), α-Fe2O3, ß-Fe2O3, γ-Fe3O4, and nZVI nanoparticles (NPs) were applied in soil as fertilizer to enhance the Fe nutrition in cherry radish. The highest enhancement of Fe content (58%) was observed in Fe3O4 treatment at 100 mg kg-1, followed by FeO(OH) (49%), α-Fe2O3 (24%), nZVI (14%), ß-Fe2O3 (13%) and γ-Fe3O4 (4%). The daily intake of Fe was 97-104% and 77-91% with Fe3O4 and FeO(OH) at 100-200 mg kg-1, respectively. Moreover, the zinc, vitamin C and crude protein contents were also increased by 37, 48 and 67% under Fe3O4 treatment as compared to control. Fe3O4 at 100 mg kg-1 also increased the essential amino acids (phenylalanine, leucine and isoleucine) contents by 11-14%. These data suggest that Fe3O4 and FeO(OH) NPs could be effective nanofertilizers to enhance Fe nutrition in plants.

Absorption of Carbon-13 Labelled Fullerene (C60) on Rice Seedlings and Effect of Phytohormones on Growth.

This study explores the effects of nanomaterials in rice seedlings using carbon 13 (13C)-labelled fullerene (C60). The experiment consisted of three groups, one CK and two nano particle groups with C60: 100 mg L-1 and 20 mg L-1. Mass spectrometry indicated higher 13C abundances in the nano particle groups compared with the CK. The 13C abundances of the 20 mg L-1 group, 100 mg L-1 group and CK were 1.0718%, 1.0715% and 1.0704%, respectively. We analyzed phytohormone concentrations in the rice at harvest time. Decreases in the concentrations of dihydrozeatin riboside (23% and 18% for the 20 mg L-1 and 100 mg L-1 group, respectively), zeatin riboside (23% and 18%, respectively), abscisic acid (11.1% and 12.7%, respectively), brassinolide (12.9% and 13.1%, respectively) and gibberellic acid 4 (12.9% and 13.1%, respectively) were observed compared with the CK. The gibberellic acid 3 concentrations in the 20 mg L-1 and 100 mg L-1 group increased by 12% and 7% compared with the CK, respectively. The methyl jasmonate concentration in the 100 mg L-1 group increased by 19.4% compared with the CK. The concentration of indole-3-acetic acid in the 100 mg L-1 group decreased by 13.5% compared with the CK. There was no change on isopentenyl adenosine concentration. This study indicates that C60 can be absorbed by rice and its effect on the growth of rice via phytohormones, including ABA, IAA, IPA, BR, GA3, GA4, DHZR, ZR and JA-ME. The results showed that, under the treatments of C60 NMs, the contents of some phytohormone in rice were decreased in comparison with CK.

Engineered Nanomaterials Suppress the Soft Rot Disease (Rhizopus stolonifer) and Slow Down the Loss of Nutrient in Sweet Potato.

About 45% of the world's fruit and vegetables are wasted, resulting in postharvest losses and contributing to economic losses ranging from $10 billion to $100 billion worldwide. Soft rot disease caused by Rhizopus stolonifer leads to postharvest storage losses of sweet potatoes. Nanoscience stands as a new tool in our arsenal against these mounting challenges that will restrict efforts to achieve and maintain global food security. In this study, three nanomaterials (NMs) namely C60, CuO, and TiO2 were evaluated for their potential application in the restriction of Rhizopus soft rot disease in two cultivars of sweet potato (Y25, J26). CuO NM exhibited a better antifungal effect than C60 and TiO2 NMs. The contents of three important hormones, indolepropionic acid (IPA), gibberellic acid 3 (GA-3), and indole-3-acetic acid (IAA) in the infected J26 sweet potato treated with 50 mg/L CuO NM were significantly higher than those of the control by 14.5%, 10.8%, and 24.1%. CuO and C60 NMs promoted antioxidants in both cultivars of sweet potato. Overall, CuO NM at 50 mg/L exhibited the best antifungal properties, followed by TiO2 NM and C60 NM, and these results were further confirmed through scanning electron microscope (SEM) analysis. The use of CuO NMs as an antifungal agent in the prevention of Rhizopus stolonifer infections in sweet potatoes could greatly reduce postharvest storage and delivery losses.

Different physiological responses of C3 and C4 plants to nanomaterials.

Several studies have previously reported that nanomaterial uptake and toxicity in plants are species dependent. However, the differences between photosynthetic pathways, C3 and C4, following nanomaterial exposure are poorly understood. In the current work, wheat and rice, two C3 pathway species are compared to amaranth and maize, which utilize the C4 photosynthetic mechanism. These plants were cultured in soils which were spiked with CuO, Ag, TiO2, MWCNT, and FLG nanomaterials. Overall, the C4 plant exhibited higher resilience to NM stress than C3 plants. In particular, significant differences were observed in chlorophyll contents with rice returning a 40.9-54.2% decrease compared to 3.5-15.1% for maize. Fv/Fm levels were significantly reduced by up to 51% in rice whereas no significant reductions were observed in amaranth and maize. Furthermore, NM uptake in the C3 species was greater than that in C4 plants, a trend that was also seen in metal concentration. TEM results showed that CuO NPs altered the chloroplast thylakoid structure in rice leaves and a large number of CuO NPs were observed in the vascular sheath cells. In contrast, there were no significant changes in the chloroplasts in the vascular sheath and no significant CuO NPs were found in maize leaves. This study was the first to systematically characterize the effect of metal and carbon-based nanomaterials in soil on C3 and C4 plants, providing a new perspective for understanding the impact of nanomaterials on plants.

Effects of spraying nano-materials on the absorption of metal(loid)s in cucumber.

This report investigates the spraying of nano-silica and fullerene on cucumber leaves to expose their ability to reduce the toxicity and uptake of metal(loid)s. Cucumber seedlings were randomly divided into six treatment groups: 10 mg/L nano-SiO2, 20 mg/L nano-SiO2, 10 mg/L Fullerene, 20 mg/L Fullerene, 5 mg/L Fullerene + 5 mg/L nano-SiO2, and 10 mg/L Fullerene + 10 mg/L nano-SiO2. Nano-silica-treated plants exhibited evidence of the potential mitigation of metal(loid)s poisoning. Specifically, results showed that 20 mg/L of nano-silica promoted Cd uptake by plants; comparatively, 10 mg/L of nano-silica did not significantly increase the silicon content in plants. Both low-concentration combined treatment and low-concentration fullerene groups inhibited metal(loid)s uptake by plants. Scanning electron microscopy (SEM) was then used to observe the surface morphology of cucumber leaves. Significant differences were observed on disease resistance in plants across the different nano-material conditions. Collectively, these findings suggest that both nano-silica materials and fullerene have the potential to control metal(loid)s toxicity in plants.