Efeito dos elicitores metil jasmonato e ácido salicílico nas respostas biométricas, bioquímicas, teor e perfil do óleo essencial de Lippia alba (Verbenaceae) sob restrição hídrica

Abstract

Lippia alba is a plant of great pharmacological interest as it has antimicrobial, calming, antioxidant properties, among others. Water restriction (WR) has already managed to positively modulate the Essential Oil of this plant. Elicitors are factors, molecules or agents capable of stimulating the defense system of plants when incorporated by them, which can cause modulations in the production of bioactive compounds. This work seeks to investigate plant responses elicited by Salicylic Acid (SA) and Methyl Jasmonate (MeJA) in combination, associated with WR. Thus, in a greenhouse, L. alba plants were subjected to five elicitation treatments: Control, 1% ethanol Control, 2 mM MeJA, 4 mM SA and 2 mM MeJA + 4 mM SA and subjected to the following regimes water: 70% (Control) and 10% (Severe water restriction) of the vessel capacity. Biometric, biochemical aspects and essential oil content were evaluated. We observed that the control treatments did not differ statistically from each other in any aspect evaluated. Of the results found, the best performances were found in treatments subjected to WR elicited with MeJA+SA and MeJA, respectively. The combined elicitation was able to improve the chlorophyll a and carotenoid content and the essential oil content of L. alba. MeJA was able to increase the levels of chlorophyll b, total chlorophylls and relative water content. SA did not stand out positively in WR conditions. We recommend the use of cross-elicitation of SA and MeJA submitted to WR, as well as elicitation by MeJA, given the effectiveness in increasing the aforementioned parameters. We do not suggest combining SA with WR given the negative effect on the aforementioned parameters.