Amir E. Kaziem,Liupeng Yang,Yigang Lin,Anas E. Kazem,Hanhong Xu,Zhi-xiang Zhang
Site-specific pesticide delivery is one of the potential strategies to enhance the use of fungicides and decrease undesirable environmental damages. Herein, a β-glucanase enzyme-responsive nanovehicle used for controlling chlorothalonil (CHT) release in the plant vascular system was synthesized (CHT@MSNs-β-glucans) by attaching β-glucans extracted from the yeast cell wall on MSNs pore rims for the management of rice blast (Magnaporthe grisea). CHT@MSNs-β-glucans characteristics were examined by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transfer infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), N2 isotherm, and Zetasizer. The obtained results showed that CHT@MSNs-β-glucans have excellent enzymatic release dependency, an outstanding loading efficacy of 24.99%, remarkable protection from acidic and alkaline conditions, and UV shielding ability up to 3 times greater than that of CHT commercial product (CHT-WP). CHT@MSNs-β-glucans showed excellent bioactivity against rice blast compared with CHT-WP. Moreover, CHT@MSNs-β-glucans showed better distribution in different tissues of rice plants. Additionally, CHT@MSNs-β-glucans showed 2.6 times lower toxicity to Daphnia magna and exhibited lower changes in soil microbial abundance than CHT-WP. This study provides significant sustainable management of plant pathogens for better farming.
The fungicide chlorothalonil (CHT) has been widely used in the tea orchard due to its high-efficiency and sterilization. It has been reported that repeated application of CHT inhibits soil nitrification process. However, the acute impact of CHT on soil denitrification and associated N 2 O emissions is unclear. This study evaluated nitrate (NO 3 − ) removal, denitrifying gene abundance and denitrifying enzyme activity of tea orchard soil after a 72-h-exposure to CHT. It was found that increasing CHT from 5 to 25 mg kg −1 suppressed the NO 3 − removal efficiency from 74.6% to 54.1%, but increased N 2 O emissions from 23.1% to 94.8%. Following treatment with 25 mg kg −1 of CHT, the abundances of the nir K, nir S and nos Z genes were reduced by 31.6%, 22.1%, and 50.7%, respectively. Alternatively, the declines of the electron transport system activity (ETSA) value and adenosine triphosphate (ATP) content suggested that CHT had an inhibitory effect on microbial metabolism. Enzyme activity studies further revealed that the decrease of nitrate reductase (NAR), nitrite reductase (NIR) and nitric oxide reductase (NOR) activities was the main reason for the suppression of denitrification by CHT. Furthermore, positive correlations were observed between denitrifying reductase activity and the intracellular metabolism, indicating that the decrease in microbial metabolism should also be responsible for the inhibitory effect of CHT on the denitrifying process. Overall, it was found that the acute exposure of soil to CHT could inhibit the denitrification process and significantly increase N 2 O emissions, which might result in destruction of the soil nitrogen cycle and exacerbation of global warming .
Yanhua Wang,Cuiyuan Jin,Dou Wang,Jiajie Zhou,Guiling Yang,Kan Shao,Qiang Wang,Yuanxiang Jin
Chlorothalonil (CHL) and procymidone (PRO) are fungicides that exhibit low toxicity and are widely used in many countries. And both fungicides are frequently detected in the food chain. However, the health risk posed by these fungicides is still unclear. Here, 8-week-old male C57BL/6 mice were orally treated with CHL (10, 50 mg/kg/day), PRO (20, 100 mg/kg/day) and CHL+PRO (5+10, 25+50 mg/kg/day) by dietary supplementation for 10 weeks. Hepatic pathological analysis showed that exposure to CHL, PRO and CHL+PRO could cause liver injury. The glucose, triglyceride (TG) levels and the related gene expression to glucolipid metabolism changed significantly. The significantly reduced acylcarnitine levels demonstrated that CHL, PRO and CHL+PRO exposure inhibited fatty acids (FAs) β-oxidation. In addition, CHL and PRO altered the structure of the gut microbiota and destroyed the integrity of the intestinal barrier function. In particular, AF12 , Odoribacter , Prevotella and Lactobacillus were highly correlated with carnitine . The results showed that CHL, PRO and CHL+PRO exposure might inhibit FAs β-oxidation by decreasing cystic fibrosis transmembrane conductance regulator (CFTR)-mediated ion transport, indicating that these fungicides disturbed intestinal barrier function associated with glucolipid metabolism disorder. Here, the data also indicated that there was an additive effect between CHL and PRO in mice.
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