Alterações transcricionais e metabólicas em Alternanthera sessilis e Alternanthera philoxeroides, elicitadas com metil jasmonato, revelam o potencial dessas espécies na produção de betalaínas

Abstract

Natural products with functional properties are increasingly attracting the interest of the pharmaceutical and food industries, partly driven by the change in habits of the population that is more inclined to consume natural products. Among these products we can highlight the dyes, which are additives present in a wide range of commercial products. However, the substitution of synthetic ingredients by natural ones is not simple, usually due to the oxidation suffered by them, there is a loss of their properties, generating limited stability during processing and storage. Betalains, which are produced exclusively by plants of the order Caryophyllales, have been highlighted, as they are able to remain stable over a larger pH range and regenerate after thermal processing. Currently the most used source for the extraction of betalains is beet, but with low acceptability due to the odor and residual taste of earth, making the search for new sources of this pigment necessary. In this sense, the objective of this work was to evaluate the potential of two species, A. philoxeroides and A. sessilis, in the production of betalains and other bioactive compounds of commercial interest through the use of methyl jasmonate (MeJA) as an elicitor to increase production. For this purpose, three studies were proposed, one involving the analysis of the transcriptome of the plant A. sessilis, submitted to elicitation with MeJA for 48 hours, to evaluate how much this elicitor was able to alter the gene expressions of this species, another in which the normalizing genes for RT-qPCR more suitable for both species and thus enabling the correct evaluation of gene expression and a third to relate the metabolic and molecular regulation caused by exposure to the elicitor over time in both species with the quantification of bioactive metabolites. The results showed that in the analysis of the transcriptome of A. sessilis exposed to MeJA there was a molecular reprogramming that resulted in the differential expression of 1,088 genes, of which 397 dowregulated and 691 upregulated. Among those that increased, most were related to secondary metabolism and amino acids. Regarding the normalizers for use in RT- qPCR, the data showed that although A. philoxeroides and A. sessilis underwent the same treatment condition and belong to the same gender, the reference genes chosen by the statistical algorithms differed. While for A. philoxeroides it was TH7 and UBQ, for A. sessilis it was GAPCP-1 and ACS. The last study showed that the two species increased the concentration of bioactive compounds when exposed to MeJA, with emphasis on the species A. sessilis, which had an increase of 44.6% in amarantine, 107.45% of total phenols and 65.3% of flavonoids. In addition, it was possible to observe that there are different mechanisms of metabolic regulation caused by MeJA between species, while in A. sessilis there seems to be negative feedback involving the amino acid tyrosine, in A. philoxeroides there is a compensation strategy between phenylalanine and tyrosine. It is concluded that MeJA is an elicitor agent capable of altering the expression of genes, in addition to providing an increase in the formation of metabolites of interest in both species.