Influência do glifosato na expressão gênica de clones de conilon

Abstract

Coffee growing is one of the main agricultural activities in the state of Espírito Santo. This activity is greatly hampered by the presence of weeds, which are commonly controlled chemically through the use of glyphosate. Glyphosate can have a negative impact on coffee plants, leading to indirect inhibition of the expression of genes involved in the secondary metabolite synthesis pathway. These substances are responsible for producing molecules with structural functions, plant defense substances, as well as being related to the quality of the coffee drink. The objective of this study was to evaluate the influence of glyphosate on the expression of genes involved in the synthesis of compounds associated with the quality of the drink. The field experiment was conducted at the Experimental Farm of the Capixaba Institute for Research, Technical Assistance and Rural Extension (Incaper) in Marilândia, Espírito Santo. The study was carried out in a two-block design with three randomized replications with seven treatments. The evaluations were carried out over a period of two years, with three collections, one in the first year and two in the second. Gene expression analyzes were carried out using RNA extraction, aiming to establish relationships between gene expressions according to the application of glyphosate, application nozzle, collection times and coffee clones. The EPSPS, CTgS1 and CCoAOMT genes were evaluated, using the CcUBQ10 gene as a reference. The data were subjected to analysis of variance (anova) and the mean grouping test using the Tukey algorithm at a 5% probability level. The results of the study found that there was variation in the gene expression of the EPSPS, CCoAOMT and CTgS1 genes. However, this variation appears not to have been solely due to the influence of glyphosate based on the types of management tested, collection times or clones. Suggesting that this variation may have been related to external factors characteristic of the field, such as climatic factors, soil characteristics, as well as interactions between plants and the environment. Despite the effects of glyphosate, the management currently carried out by the producers tested in this study does not seem to cause harm to the expression of these genes, nor to the health of the coffee plant and the quality of the coffee drink.