Abstract
BackgroundFlesh is prone to accumulate more anthocyanin in postharvest ‘Friar’ plum (Prunus salicina Lindl.) fruit stored at an intermediate temperature. However, little is known about the molecular mechanism of anthocyanin accumulation regulated by storage temperature in postharvest plum fruit.ResultsTo reveal the potential molecular regulation mechanism of anthocyanin accumulation in postharvest ‘Friar’ plum fruit stored at different temperatures (0 °C, 10 °C and 25 °C), the fruit quality, metabolite profile and transcriptome of its flesh were investigated. Compared to the plum fruit stored at 0 °C and 25 °C, the fruit stored at 10 °C showed lower fruit firmness after 14 days and reduced the soluble solids content after 21 days of storage. The metabolite analysis indicated that the fruit stored at 10 °C had higher contents of anthocyanins (pelargonidin-3-O-glucoside, cyanidin-3-O-glucoside, cyanidin-3-O-rutinoside and quercetin-3-O-rutinose), quercetin and sucrose in the flesh. According to the results of weighted gene coexpression correlation network analysis (WGCNA), the turquoise module was positively correlated with the content of anthocyanin components, and flavanone 3-hydroxylase (F3H) and chalcone synthase (CHS) were considered hub genes. Moreover, MYB family transcription factor APL (APL), MYB10 transcription factor (MYB10), ethylene-responsive transcription factor WIN1 (WIN1), basic leucine zipper 43-like (bZIP43) and transcription factor bHLH111-like isoform X2 (bHLH111) were closely related to these hub genes. Further qRT–PCR analysis verified that these transcription factors were specifically more highly expressed in plum flesh stored at 10 °C, and their expression profiles were significantly positively correlated with the structural genes of anthocyanin synthesis as well as the content of anthocyanin components. In addition, the sucrose biosynthesis-associated gene sucrose synthase (SS) was upregulated at 10 °C, which was also closely related to the anthocyanin content of plum fruit stored at 10 °C.ConclusionsThe present results suggest that the transcription factors APL, MYB10, WIN1, bZIP43 and bHLH111 may participate in the accumulation of anthocyanin in ‘Friar’ plum flesh during intermediate storage temperatures by regulating the expression of anthocyanin biosynthetic structural genes. In addition, the SS gene may play a role in anthocyanin accumulation in plum flesh by regulating sucrose biosynthesis.
Highlights
Flesh is prone to accumulate more anthocyanin in postharvest ‘Friar’ plum (Prunus salicina Lindl.) fruit stored at an intermediate temperature
Effect of different storage temperatures on the fruit quality of ‘Friar’ plum Within 28 days of storage, there were no obvious colour changes in the flesh of fruit stored at 0.5 °C (0 °C) and 25 ± °C (25 °C), while the flesh of fruit stored at 10 ± 0.5 °C (10 °C) turned red on the 14th day of storage (Fig. 1a)
Identification of the anthocyanin and phenolic metabolite profile related to flesh reddening The UPLC–MS/MS results showed that the anthocyanins in the flesh of ‘Friar’ plum fruit mainly contained pelargonidin 3-O-glucoside, cyanidin-3-O-glucoside, cyanidin-3-O-rutinoside, and quercetin-3-O-rutinose, and their contents were much higher in fruit stored at 10 °C after 21 days than in those stored at 0 °C and 25 °C (Fig. 2a-d)
Summary
Flesh is prone to accumulate more anthocyanin in postharvest ‘Friar’ plum (Prunus salicina Lindl.) fruit stored at an intermediate temperature. Little is known about the molecular mechanism of anthocyanin accumulation regulated by storage temperature in postharvest plum fruit. The MBW complex positively regulates the expression of structural genes by binding to cis-acting elements on the promoter regions of genes (such as DFR, LDOX/ANS, UFGT, etc.) and facilitates the accumulation of anthocyanin in plants [7, 9,10,11,12]. Transcription factors such as COP1 (CONSTITUTIVE PHOTOMORPHOGENIC 1), JAZ (JASMONATE ZIMDOMAIN), NAC (NAM, ATAF1/2, CUC2), SPL (SQUAMOSA promoter-binding protein-like) and WRKY have been considered to regulate anthocyanin biosynthesis by interacting with the MBW complex [13,14,15,16,17,18]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
