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.