Limits...
Evaluation of the side effects of poly(epsilon-caprolactone) nanocapsules containing atrazine toward maize plants.

Oliveira HC, Stolf-Moreira R, Martinez CB, Sousa GF, Grillo R, de Jesus MB, Fraceto LF - Front Chem (2015)

Bottom Line: These results suggested that the negative effects of atrazine were transient, probably due to the ability of maize plants to detoxify the herbicide.Regardless of the herbicide concentration, neither pre- nor post-emergence treatment with the PCL nanocapsules carrying atrazine resulted in the development of any macroscopic symptoms in maize leaves, and there were no impacts on shoot growth.Additionally, no effects were observed when plants were sprayed with PCL nanocapsules without atrazine.

View Article: PubMed Central - PubMed

Affiliation: Department of Animal and Plant Biology, University of Londrina Londrina, Brazil.

ABSTRACT
Poly(epsilon-caprolactone) (PCL) nanocapsules have been used as a carrier system for the herbicide atrazine, which is commonly applied to maize. We demonstrated previously that these atrazine containing polymeric nanocapsules were 10-fold more effective in the control of mustard plants (a target species), as compared to a commercial atrazine formulation. Since atrazine can have adverse effects on non-target crops, here we analyzed the effect of encapsulated atrazine on growth, physiological and oxidative stress parameters of soil-grown maize plants (Zea mays L.). One day after the post-emergence treatment with PCL nanocapsules containing atrazine (1 mg mL(-1)), maize plants presented 15 and 21% decreases in maximum quantum yield of photosystem II (PSII) and in net CO2 assimilation rate, respectively, as compared to water-sprayed plants. The same treatment led to a 1.8-fold increase in leaf lipid peroxidation in comparison with control plants. However, all of these parameters were unaffected 4 and 8 days after the application of encapsulated atrazine. These results suggested that the negative effects of atrazine were transient, probably due to the ability of maize plants to detoxify the herbicide. When encapsulated atrazine was applied at a 10-fold lower concentration (0.1 mg mL(-1)), a dosage that is still effective for weed control, no effects were detected even shortly after application. Regardless of the herbicide concentration, neither pre- nor post-emergence treatment with the PCL nanocapsules carrying atrazine resulted in the development of any macroscopic symptoms in maize leaves, and there were no impacts on shoot growth. Additionally, no effects were observed when plants were sprayed with PCL nanocapsules without atrazine. Overall, these results suggested that the use of PCL nanocapsules containing atrazine did not lead to persistent side effects in maize plants, and that the technique could offer a safe tool for weed control without affecting crop growth.

No MeSH data available.


Related in: MedlinePlus

Maximum photosystem II quantum yields of maize plants submitted to post-emergence treatment with the formulations. Chlorophyll fluorescence parameters were evaluated 1, 2, 4, and 8 days after the plants were sprayed with 3.1 mL of water, empty PCL nanocapsules (NC), commercial atrazine (ATZ), or PCL nanocapsules containing atrazine (NC+ATZ). The formulations containing atrazine at 1 mg mL−1 were used undiluted or after 10-fold dilution in water (1/10), resulting in atrazine application dosages of 2000 or 200 g ha−1, respectively. Different letters for each time point indicate significantly different values, according to One-Way ANOVA followed by Tukey's test (P < 0.05). Data are shown as means ± SE (n = 5).
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4612713&req=5

Figure 1: Maximum photosystem II quantum yields of maize plants submitted to post-emergence treatment with the formulations. Chlorophyll fluorescence parameters were evaluated 1, 2, 4, and 8 days after the plants were sprayed with 3.1 mL of water, empty PCL nanocapsules (NC), commercial atrazine (ATZ), or PCL nanocapsules containing atrazine (NC+ATZ). The formulations containing atrazine at 1 mg mL−1 were used undiluted or after 10-fold dilution in water (1/10), resulting in atrazine application dosages of 2000 or 200 g ha−1, respectively. Different letters for each time point indicate significantly different values, according to One-Way ANOVA followed by Tukey's test (P < 0.05). Data are shown as means ± SE (n = 5).

Mentions: Both commercial atrazine (ATZ) and PCL nanocapsules containing atrazine (NC+ATZ) decreased the maximum quantum yield of PSII 1 day after the treatment of maize plants, as compared to control plants (Figure 1). These results are coherent with the inhibitory action of atrazine in PSII. Greater inhibition was caused by NC+ATZ (Fv/Fm = 0.67), as compared to ATZ (Fv/Fm = 0.74). However, the effects of the two formulations were transient, because the Fv/Fm ratios for plants treated with ATZ or NC+ATZ recovered to the same values obtained for control plants 2 or 4 days after treatment, respectively. When 10-fold diluted atrazine-containing formulations (ATZ 1/10 and NC+ATZ 1/10) were applied, no effects on PSII photochemistry were observed, even after shorter times. Regardless of the dilution, the treatments with nanocapsules without atrazine (NC and NC 1/10) also had no effect on the Fv/Fm ratio of the maize plants.


Evaluation of the side effects of poly(epsilon-caprolactone) nanocapsules containing atrazine toward maize plants.

Oliveira HC, Stolf-Moreira R, Martinez CB, Sousa GF, Grillo R, de Jesus MB, Fraceto LF - Front Chem (2015)

Maximum photosystem II quantum yields of maize plants submitted to post-emergence treatment with the formulations. Chlorophyll fluorescence parameters were evaluated 1, 2, 4, and 8 days after the plants were sprayed with 3.1 mL of water, empty PCL nanocapsules (NC), commercial atrazine (ATZ), or PCL nanocapsules containing atrazine (NC+ATZ). The formulations containing atrazine at 1 mg mL−1 were used undiluted or after 10-fold dilution in water (1/10), resulting in atrazine application dosages of 2000 or 200 g ha−1, respectively. Different letters for each time point indicate significantly different values, according to One-Way ANOVA followed by Tukey's test (P < 0.05). Data are shown as means ± SE (n = 5).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4612713&req=5

Figure 1: Maximum photosystem II quantum yields of maize plants submitted to post-emergence treatment with the formulations. Chlorophyll fluorescence parameters were evaluated 1, 2, 4, and 8 days after the plants were sprayed with 3.1 mL of water, empty PCL nanocapsules (NC), commercial atrazine (ATZ), or PCL nanocapsules containing atrazine (NC+ATZ). The formulations containing atrazine at 1 mg mL−1 were used undiluted or after 10-fold dilution in water (1/10), resulting in atrazine application dosages of 2000 or 200 g ha−1, respectively. Different letters for each time point indicate significantly different values, according to One-Way ANOVA followed by Tukey's test (P < 0.05). Data are shown as means ± SE (n = 5).
Mentions: Both commercial atrazine (ATZ) and PCL nanocapsules containing atrazine (NC+ATZ) decreased the maximum quantum yield of PSII 1 day after the treatment of maize plants, as compared to control plants (Figure 1). These results are coherent with the inhibitory action of atrazine in PSII. Greater inhibition was caused by NC+ATZ (Fv/Fm = 0.67), as compared to ATZ (Fv/Fm = 0.74). However, the effects of the two formulations were transient, because the Fv/Fm ratios for plants treated with ATZ or NC+ATZ recovered to the same values obtained for control plants 2 or 4 days after treatment, respectively. When 10-fold diluted atrazine-containing formulations (ATZ 1/10 and NC+ATZ 1/10) were applied, no effects on PSII photochemistry were observed, even after shorter times. Regardless of the dilution, the treatments with nanocapsules without atrazine (NC and NC 1/10) also had no effect on the Fv/Fm ratio of the maize plants.

Bottom Line: These results suggested that the negative effects of atrazine were transient, probably due to the ability of maize plants to detoxify the herbicide.Regardless of the herbicide concentration, neither pre- nor post-emergence treatment with the PCL nanocapsules carrying atrazine resulted in the development of any macroscopic symptoms in maize leaves, and there were no impacts on shoot growth.Additionally, no effects were observed when plants were sprayed with PCL nanocapsules without atrazine.

View Article: PubMed Central - PubMed

Affiliation: Department of Animal and Plant Biology, University of Londrina Londrina, Brazil.

ABSTRACT
Poly(epsilon-caprolactone) (PCL) nanocapsules have been used as a carrier system for the herbicide atrazine, which is commonly applied to maize. We demonstrated previously that these atrazine containing polymeric nanocapsules were 10-fold more effective in the control of mustard plants (a target species), as compared to a commercial atrazine formulation. Since atrazine can have adverse effects on non-target crops, here we analyzed the effect of encapsulated atrazine on growth, physiological and oxidative stress parameters of soil-grown maize plants (Zea mays L.). One day after the post-emergence treatment with PCL nanocapsules containing atrazine (1 mg mL(-1)), maize plants presented 15 and 21% decreases in maximum quantum yield of photosystem II (PSII) and in net CO2 assimilation rate, respectively, as compared to water-sprayed plants. The same treatment led to a 1.8-fold increase in leaf lipid peroxidation in comparison with control plants. However, all of these parameters were unaffected 4 and 8 days after the application of encapsulated atrazine. These results suggested that the negative effects of atrazine were transient, probably due to the ability of maize plants to detoxify the herbicide. When encapsulated atrazine was applied at a 10-fold lower concentration (0.1 mg mL(-1)), a dosage that is still effective for weed control, no effects were detected even shortly after application. Regardless of the herbicide concentration, neither pre- nor post-emergence treatment with the PCL nanocapsules carrying atrazine resulted in the development of any macroscopic symptoms in maize leaves, and there were no impacts on shoot growth. Additionally, no effects were observed when plants were sprayed with PCL nanocapsules without atrazine. Overall, these results suggested that the use of PCL nanocapsules containing atrazine did not lead to persistent side effects in maize plants, and that the technique could offer a safe tool for weed control without affecting crop growth.

No MeSH data available.


Related in: MedlinePlus