Low doses of glyphosate do not damage the secondary metabolism of common bean

Abstract

Glyphosate application, even in low doses, changes the metabolism of crops. This research aimed to evaluate the effects of glyphosate low doses and sowing season on metabolic changes of early-cycle common beans. Two experiments were conducted in the field, one in the winter season and one in the wet season. The experimental design was a randomized complete block design consisting of the application of glyphosate low doses [0.0, 1.8, 7.2, 12.0, 36.0, 54.0, and 108.0 g acid equivalent (a.e.) ha⁻¹] in the phenological stage V4 with four replications. In the winter season, glyphosate and shikimic acid were increased five days after the application of treatments. In contrast, the same compounds increased only at doses of 36 g a.e. ha⁻¹ and above in the wet season. The dose of 7.2 g a.e. ha⁻¹ increased phenylalanine ammonia-lyase and benzoic acid in the winter season. The doses of 54 and 108 g a.e. ha⁻¹ increased benzoic acid, caffeic acid, and salicylic acid. Our study indicated that glyphosate low doses increase the concentration of shikimic, benzoic, salicylic and caffeic acid, PAL and tyrosine. There was no reduction in aromatic amino acids and in secondary compounds from the shikimic acid pathway.

Graphical abstract

Keywords:

• Phaseolus vulgaris L
• hormesis
• secondary metabolites
• PAL enzyme

Acknowledgments

Authors thank the Instituto Agronômico de Campinas (IAC, SP, Brazil), represented by scientific researcher Alisson Fernando Chiorato, for the supply of common bean seeds.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

Raw data were generated at São Paulo State University, Botucatu Campus, SP, Brazil. Derived data supporting the findings of this study are available from the corresponding author M.d.A.S. on request.

Additional information

Funding

We are grateful for financial support of National Council for Scientific and Technological Development (CNPq, Brazil) through “PhD” fellowship for FPAPB (Proc. 162258/2015-1) and “Productivity in Research” fellowship for MAS (Proc. 305952/2018-8).