PpGST1, an anthocyanin‐related glutathione S‐transferase gene, is essential for fruit coloration in peach

Abstract

Summary Anthocyanins have crucial biological functions and affect quality of horticultural produce. Anthocyanins accumulate in ripe peach fruit; differential accumulation is observed in deep coloured cultivar ‘Hujingmilu’ and lightly pigmented cultivar ‘Yulu’. The difference was not fully explained by accumulation of total flavonoids and expression of anthocyanin biosynthetic genes. Expression analysis was conducted on a glutathione S‐transferase gene (PpGST1), and it was found that the expression correlated well with anthocyanin accumulation in peach fruit tissues. Functional complementation of the Arabidopsis tt19 mutant indicated that PpGST1 was responsible for transport of anthocyanins but not proanthocyanidins. PpGST1 was localized in nuclei and the tonoplast, including the sites at which anthocyanin vacuolar sequestration occurred. Transient overexpression of PpGST1 together with PpMYB10.1 in tobacco leaves and peach fruit significantly increased anthocyanin accumulation as compared with PpMYB10.1 alone. Furthermore, virus‐induced gene silencing of PpGST1 in a blood‐fleshed peach not only resulted in a reduction in anthocyanin accumulation but also a decline in expression of anthocyanin biosynthetic and regulatory genes. Cis‐element analysis of the PpGST1 promoter revealed the presence of four MYB binding sites (MBSs). Dual‐luciferase assays indicated that PpMYB10.1 bound to the promoter and activated the transcription of PpGST1 by recognizing MBS1, the one closest to the ATG start codon, with this trans‐activation being stronger against the promoter of deep coloured ‘Hujingmilu’ compared with lightly coloured cultivar ‘Yulu’. Altogether, our data provided molecular evidence supporting coordinative regulatory roles of PpGST1 and PpMYB10.1 in anthocyanin accumulation in peach.

Transcriptomic Profiling of Apple Calli With a Focus on the Key Genes for ALA-Induced Anthocyanin Accumulation

“…For anthocyanin sequestration, several members of GST- and MATE-encoded enzymes are required for anthocyanin transport from cytoplasm to vacuole. Some members of GST have been identified to be responsible for anthocyanin transport in Arabidopsis ( Kitamura et al, 2004 ), grapes ( Gomez et al, 2011 ), litchi ( Hu et al, 2016 ), peach ( Zhao et al, 2020 ), and apple ( El-sharkawy et al, 2015 ; Jiang et al, 2019 ). Some MATE family members also showed positive correlation with anthocyanin transport ( Mathews et al, 2003 ; Marinova et al, 2007 ; Frank et al, 2011 ; Gomez et al, 2011 ; Zhao et al, 2011 ).…”

The Photomorphogenic Transcription Factor PpHY5 Regulates Anthocyanin Accumulation in Response to UVA and UVB Irradiation

“…The dual-luciferase assay was performed with Nicotiana benthamiana leaves by using a previously reported protocol ( Zhao et al, 2020 ). Agrobacterium cultures containing recombinant pGreenII 0029 62-SK vectors harboring transcription factor genes and the cultures containing recombinant pGreen II 0800-LUC vector harboring target gene promoters were infiltrated into N .…”

“…The Agrobacterium strain carrying the 35S:: PpHY5 -GFP or 35S:: PpCOP1.1 -GFP recombinant vector was infiltrated into transgenic N . benthamiana plant with a red fluorescent nuclear marker (Nucleus-RFP) according to a previous report ( Zhao et al, 2020 ), while 35S::GFP was used as a negative control. The GFP florescence of the transiently expressed leave was observed under a Zeiss LSM710NLO confocal laser scanning microscope.…”

Spotlight on the overlapping routes and partners for anthocyanin transport in plants

“…Besides this, Sun et al (2012) reported that loss‐of‐function mutants of TT19 from Arabidopsis thaliana result in a significant reduction in the level of anthocyanin in the vegetative parts as well as brown pigments in the seed coat, which demonstrated their role in the vacuolar uptake of both anthocyanins and PAs precursors (Kitamura et al, 2004). Furthermore, various complementation assays showed that PpGST, LcGST, CsGSTF1 , and MdGSTF6 from peach, litchi, purple tea, and apple, respectively, mediate the transport of anthocyanins but not PAs, whereas VviGST4 and AcGST1 from grapevine and kiwifruit participate in the transport of only PAs (Zhao et al, 2020; Hu, Sun, et al, 2016; Wei et al, 2018; Jiang et al, 2019; Pérez‐Díaz et al, 2016; Liu et al, 2019, respectively).…”