Abstract

Fragaria chiloensis is an endemic rosacea from Chile, being its fruit intense in flavor, attractive color and pleasant aroma. However, the fast fruit softening is one of the main problems. One NAM, ATAF1,2, and CUC gene was isolated from fruit tissues, encoding 332 amino acids. The protein contains the conserved NAC domain, subdivided into 5 subdomains. High evolutionary proximity with others NAC transcription factors related to secondary wall formation was identified. The transcription profile at different fruit stages of maturation and vegetative tissues is reported, as well as, a structural model of FcNAC1 built by comparative modeling, and showing the highly conserved NAC domain in the amino terminal region. A 1,488 bp of the FcNAC1 promoter and in-silico analysis with the presence of cis elements to hormonal responses is reported. The expression response of FcNAC1 under hormonal treatments in fruit and using dual luciferase assay were able to determine the transcriptional activation of a promoter sequence from one gene related to cell wall remodeling. The involvement of NAC during fruit softening and senescence is still unknown, and these data allow the understanding for this biological process of particular commercial interest.