Genes Analyzed We analyzed the expression level of genes previously reported as related to the following processes or pathways: JAs biosynthesis (and [33,70]), JA signaling (and [16]), MBW complex (and repressor [15]), and anthocyanin and PA biosynthetic genes ([15,71,72], Supplementary Table S10). an upregulation of and genes. Inversely, the PA content was higher in jarin-1- and MeJA + jarin-1-treated than in MeJA-treated fruits. MeJA + jarin-1 treatment resulted in an upregulation of and associated transcription factors such as and along with and genes. It is proposed that PA biosynthesis-related genes can be upregulated by the application of jarin-1 to MeJA-treated fruit, thus increasing PA accumulation in strawberry. genes 1. Introduction Herb polyphenols play a central role in herb fitness, since these compounds are important in herb environment crosstalk, playing a role in herb responses to biotic and abiotic stress, and in plants and fruits they are important for pollen fertility and animal attraction for pollination and seed dispersion [1,2,3,4]. Moreover, polyphenols have beneficial properties for human MX-69 health. In this sense, it has been reported that phenolic compounds found in berry fruits have antioxidant, antimutagenic, and free-radical scavenging activities, and increased consumption of phenolic compounds reduces the risk of cardiovascular diseases and certain types of cancer [5,6,7,8]. In this sense, strawberry ( malonyl-glucoside make up 80% and 14% of the total anthocyanin content, respectively [13], accumulating at the end of the ripening process. The final actions of biosynthesis of anthocyanin pigments in strawberry MX-69 involve the enzymes dihydroflavonol 4-reductase (DFR), anthocyanidin synthase (ANS), and uridine diphosphate (UDP) glucose:flavonoid 3-[24], [25], and [26] were characterized and named fruit, respectively [22,23,28,29]. On the other hand, herb hormones regulate fruit development and ripening, and they could be related to the accumulation of interesting bioactive compounds in fruit [30]. Unlike other Rosaceae family plants, the strawberry is considered to be a nonclimacteric fruit because the flesh does not ripen in response to the phytohormone ethylene [30,31]; thus, it plays a secondary role in fruit ripening. Other phytohormones possibly serve as major regulators in nonclimacteric fruit ripening. Abscisic acid (ABA) has been found to play a major role in the induction of nonclimacteric fruit ripening, including in strawberry [30,32]. Moreover, the bioactive jasmonate, jasmonoyl-isoleucine (JA-Ile), could play a role in anthocyanin and PA accumulation. To date, few studies have been conducted to assess the role of jasmonates (JAs) in strawberry fruit ripening, although we recently reported a study showing JA-Ile accumulation at early developmental stages and a subsequent decrease through strawberry fruit ripening [33] concomitant with the PA accumulation pattern [13,14]. In Arabidopsis seedlings, anthocyanin accumulation induced by JAs has been reported [34]. The authors suggest that pigment accumulation may be mediated by an upregulation of MBW-related components, including the MYB-types PAP1 and PAP2 and the bHLH-types GL3 TFs, which could upregulate the expression of genes encoding for DFR and UFGT enzymes that control the last actions of anthocyanin biosynthesis [34]. Regarding the connection between JA signaling and anthocyanin biosynthesis, a bHLH TF, MYC2, has been shown to be a positive regulator of JA-mediated flavonoid biosynthesis in Arabidopsis, along with the other protein family members MYC3 and MYC4 [35,36]. Moreover, previous studies showed that exogenous application of methyl jasmonate (MeJA; Physique 1A) on strawberry fruits accelerated red color acquisition, together with an improvement of other fruit quality attributes, through MX-69 greater and transient anthocyanin accumulation [37,38,39,40]. The anthocyanin accumulation in MeJA-treated Chilean strawberry ([38]. Finally, it has been described that along with anthocyanin accumulation and color acquisition, MeJA application to developing strawberry fruits induces the accumulation of JA-Ile [33]. Open in a separate window Physique 1 Representation of chemical structures for (A) methyl jasmonate (MeJA) and (B) jarin-1 molecules used in the present research. Jarin-1 molecule originally reported by Meesters et al. 2014 [41]. Additionally, jarin-1 (from jasmonic acid:amino acid synthetase (JAR1) inhibitor; Physique 1B) was validated as a Rabbit Polyclonal to PSEN1 (phospho-Ser357) chemical MX-69 inhibitor able to prevent jasmonic acid (JA) conversion into JA-Ile mediated by JAR1 in Arabidopsis [41]. Through molecular, biochemical, and chemical approaches, the enzyme JAR1 was identified as the molecular target of jarin-1 [41]. In this study, a decrease in anthocyanin accumulation and JAR1 activity was also reported for jarin-1-treated plants. In this sense, jarin-1 is an effective and promising tool for further studies on JA-Ile-related responses in Arabidopsis and other species. Recently, our group identified and characterized the key JA metabolism- and signaling-related molecular components in strawberry at the genetic and transcriptional levels [16,33]. Specifically, we reported a downregulated transcriptional profile of the encoding genes for JA-Ile and MeJA biosynthesis-related enzymes JAR1 and jasmonic acid methyl transferase (JMT), respectively [33], and for the key signaling.