Foliar Application of Sodium Nitroprusside Boosts Solanum lycopersicum L. Tolerance to Glyphosate by Preventing Redox Disorders and Stimulating Herbicide Detoxification Pathways.

Cristiano Soares,Isabel M. P. L. V. O. Ferreira,Bruno Sousa,Edgar Pinto,Francisca Rodrigues,Fernanda Fidalgo,Ruth Pereira

doi:10.3390/plants10091862

Cristiano Soares, Isabel M. P. L. V. O. Ferreira + Show 5 more

Open Access

https://doi.org/10.3390/plants10091862

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Abstract

Strategies to minimize the effects of glyphosate (GLY), the most used herbicide worldwide, on non-target plants need to be developed. In this context, the current study was designed to evaluate the potential of nitric oxide (NO), provided as 200 µM sodium nitroprusside (SNP), to ameliorate GLY (10 mg kg−1 soil) phytotoxicity in tomato plants. Upon herbicide exposure, plant development was majorly inhibited in shoots and roots, followed by a decrease in flowering and fruit set; however, the co-application of NO partially prevented these symptoms, improving plant growth. Concerning redox homeostasis, lipid peroxidation (LP) and reactive oxygen species (ROS) levels rose in response to GLY in shoots of tomato plants, but not in roots. Additionally, GLY induced the overaccumulation of proline and glutathione, and altered ascorbate redox state, but resulted in the inhibition of the antioxidant enzymes. Upon co-treatment with NO, the non-enzymatic antioxidants were not particularly changed, but an upregulation of all antioxidant enzymes was found, which helped to keep ROS and LP under control. Overall, data point towards the benefits of NO against GLY in tomato plants by reducing the oxidative damage and stimulating detoxification pathways, while also preventing GLY-induced impairment of flowering and fruit fresh mass.

Highlights

Glyphosate (GLY; N-(phosphonomethyl)glycine), the active compound of several commercial herbicides, was introduced on the pesticide market by Monsanto Company (S.A., Belgium, Europe) in the mid-1970s and has been in a leading position since [1,2,3]
Corroborating the data obtained for biometric analysis, we show that foliar treatment with nitric oxide (NO) of GLY-exposed plants results in better reactive oxygen species (ROS) management, as evidenced by generally reduced levels of O2− and H2O2, when compared to plants only exposed to GLY
The foliar application of NO successfully improved tomato plant growth and development, with a clear separation from plants exposed to the herbicide alone

Summary

Introduction

Glyphosate (GLY; N-(phosphonomethyl)glycine), the active compound of several commercial herbicides, was introduced on the pesticide market by Monsanto Company (S.A., Belgium, Europe) in the mid-1970s and has been in a leading position since [1,2,3]. As a broad-spectrum herbicide, GLY’s use was initially restricted for weed removal from cultivated fields, meadows and non-crop areas [2]. Since 1996, the introduction of transgenic GLY-resistant crops has led to a general upward trend of GLY-based herbicides application [1]. GLY is the most applied herbicide worldwide, accounting, in 2014, for more than 90% of the total herbicide market targeting the agricultural sector [4]. Paired with this increasing popularity, emerging concerns on GLY accumulation across the environment have begun to arise. Residual amounts of GLY can affect non-target plant species [8,9] since, even upon its metabolization by microorganisms and/or adsorption to soil components, the byproduct of its degradation, aminomethylphosphonic acid (AMPA), is a recognized phytotoxin [3,8]

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