Expressão de genes relacionados à via de transdução de sinal de auxina associada à maturação do melão amarelo

Abstract

Yellow melon fruit is one of the most relevant phenotypic variations of Cucumis melo in the Brazilian market and, therefore, understanding the maturation process is quite relevant to fruit production. In this context, plant hormones have been indicated as ripening regulators, such as auxin, which is active in cell division and expansion in the early stages of fruit development. Therefore, this work aimed to elucidate the gene expression of auxin signal transduction in the ripening of melon fruits, submitted to exogenous treatments with indoleacetic acid (IAA), 2,3,5-triiodobenzoic acid (TIBA), sucrose and sorbitol. The experiment was carried out in a greenhouse and at the Laboratories of Biotechnology Applied to Fruticulture and Molecular Microbial Biology of the State University of Ponta Grossa - PR, in the period 2021-2022. The design adopted was randomized blocks (DBC), integrating six treatments and four replications, applying post-harvest (physical-chemical) and gene expression analysis through RT-qPCR. The results presented here show that the concentration of 600 μM of indoleacetic acid was not enough to change some physical properties of yellow melon fruits, but it has relevance in terms of molecular physiology, suppressing the expression of CMARF3 and CmGH3.5, and inducing CmSAUR36. Exogenous sucrose, in turn, caused a significant increase in the ratio between soluble solids and titratable acidity, and in the expression of CmARF3. The concentrations of 200 μM of TIBA and sorbitol do not seem to be sufficient to increase any physical-chemical attribute in fruit maturation. Such data are relevant to further elucidate the attributes that permeate the ripening of non-climacteric yellow melon cv. Eldorado, on the crosstalk of plant hormones and sugars at the molecular level.