Metabolism of guarana (Paullinia cupana Kunth var. sorbilis) plants and fruit production subjected to glyphosate doses

Abstract

Guarana (Paullinia cupana Kunth var. sorbilis) is a typically Amazonian plant of high economic value due to the compounds found in its seed. For guarana to reach the maximum productive potential, management practices such as weed control are necessary. The use of herbicides is a viable alternative, however, its drift may lead to adverse effects on the primary and secondary plant metabolisms and cause losses in crop production. This study evaluated the differential drift effects of glyphosate doses on the physiology of guarana plants and the production of compounds of economic interest in their seeds. Glyphosate doses (57.6, 115.2, 230.4, 460.8 g ae ha⁻¹) were applied to adult guarana plants after the flowering period. The photosynthetic functions and metabolism effects were evaluated. Herbicide treatments led to oxidative stress due to increased lipid peroxidation and increased carbohydrate and amino acid in their leaflets. Despite this, glyphosate showed no effect on fruit production or the content of secondary metabolites of commercial interest in seeds.

Keywords:

• Herbicide
• drift
• weed
• plant physiology
• methylxanthine
• caffeine
• polyphenol
• catechin
• plant stress

Acknowledgments

We thank Ambev and Fazenda Santa Helena in Maués, Amazonas, Brazil, for providing the assistance and plant material for the experiment.

Additional information

Funding

This work was supported by the National Council for Scientific and Technological Development (CNPq; postdoctoral grant to RPO-G [number 152121/2019-6]) and Coordination for the Improvement of Higher Education Personnel (CAPES; research grant to GANS and postdoctoral grant FCS).