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Abstract: Chilean strawberry (Fragaria chiloensis) is a berry fruit with excellent organoleptic properties, however its fast softening limits its commercialization. Fruit softening is related to cell wall degradation and several related enzymes have been studied in strawberries, including xyloglucan endotransglycosylase/hydrolase (XTH). Two XTH genes have been identified in F. chiloensis, FcXTH1 and FcXTH2. FcXTH1 transcripts increased during fruit growth and softening, while FcXTH2 transcripts were high in vegetative tissues. XTH gene expression seems to be regulated in plants by different factors including hormones. To test their responsiveness, fruit were treated with auxin, abscisic acid, gibberellins and ethylene, and the expression of FcXTH isoforms was analysed. qPCR analysis revealed a significant variation in the expression of FcXTH genes after hormone treatments, showing an activator effect of auxins and GA3 on both FcXTH genes, an inhibitory effect of ethylene on FcXTH2, and an inductive effect of ABA on FcXTH1 gene expression. FcXTH1 and FcXTH2 gene promoters were cloned and in silico analysed to reveal putative cis elements. Different regulatory elements responding to hormones were found in each promoter sequence. The changes in expression in response to hormone treatments are consistent with the regulatory elements described in the promoter sequences of FcXTH genes. [Copyright &y& Elsevier]

One of the most important factors limiting apricot quality is the loss of flavor during storage, particularly overall aroma. To characterize fruit aroma, several techniques have been used, including both instrumental- and sensory-based methodologies. Despite the importance of aroma in fruit quality, limited information is available regarding the effects of long-term cold storage and ripening on the apricot’s volatile compound profile. The objective of this research was to characterize the aroma of two lots of Castlebrite apricots at different stages of initial maturity using gas chromatography–mass spectrometry (GC–MS), electronic nose (e-nose) analysis, and a sensory panel. GC measurements were performed on both intact fruit and ground fruit tissue. Evaluations were performed at harvest, after 15 or 30d of cold storage at 0°C under a normal air atmosphere and also after a simulated shelf-life period at 20°C. Among the volatiles identified by GC–MS, aldehydes and esters were the primary constituents of Castlebrite apricot aroma, and differences in volatile aroma profiles were observed between intact and ground fruit. Only the concentrations of aldehyde compounds, primarily hexanal, were different between maturity stages. Furthermore, the e-nose was able to successfully differentiate between the two different stages of fruit maturity examined, but only after simulated shelf-life storage. Interestingly, despite the changes detected by GC and the e-nose, the sensory panel could not identify any differences between apricots at different stages of maturity. [Copyright &y& Elsevier]