Transcriptome analysis of bagging-treated red Chinese sand pear peels reveals light-responsive pathway functions in anthocyanin accumulation

Abstract

Bagging is an efficient method to improve fruit colour development. This work reported a transcriptome analysis using bagging-treated red Chinese sand pear peels. In total, 8,870 differentially expressed genes were further analysed by a weighted gene co-expression network analysis and early-, middle- and late light-responsive genes were identified. An annotation analysis revealed several pathways involved in the different responsive stages. The presence of LONG HYPOCOTLY 5, CRY-DASH and a CONSTANS-like transcription factors among the early light-responsive genes indicated the pivotal role of light, especially blue light, in the biological changes that occurred after bag removal. Other light-responsive transcription factors were also identified from the three light-responsive stages. In addition, the light-responsive pattern of anthocyanin biosynthetic genes differed among the biosynthetic steps. Although yeast-one hybrid assay showed that most of the structural genes were regulated by PpMYB10, their different temporal expressive pattern suggested that besides PpMYB10, other light-responsive transcriptional factors were also involved in the regulation of anthocyanin biosynthesis. In summary, our transcriptome analysis provides knowledge of the transcriptional regulatory network operating during light responses, which results in anthocyanin accumulation and other significant physiological changes in red Chinese sand pear peels after bag removal.

Two B‐box proteins, PpBBX18 and PpBBX21, antagonistically regulate anthocyanin biosynthesis via competitive association with Pyrus pyrifolia ELONGATED HYPOCOTYL 5 in the peel of pear fruit

“…We previously reported that PpHY5 was involved in the regulation of light‐induced development of the red color in red Asian pear (Bai et al ., ) by binding directly to the promoter of PpMYB10 (Tao et al ., ), which is the key regulator of anthocyanin biosynthesis. In the present study we analyzed the expression of PpHY5 and PpMYB10 during continuous blue‐light irradiation using the red pear cultivar ‘Red Zaosu’.…”

BBX16, a B‐box protein, positively regulates light‐induced anthocyanin accumulation by activating MYB10 in red pear

“…In recent years, along with the introduction of local red pear cultivars into breeding programs, red Asian pears have gradually increased in the market and have gained consumers' acceptance (Zhang et al, 2013). However, unlike the European pear, which easily colours, the red Asian pear does not easily produce the red-coloured peel, especially in the warmer regions of China (Bai et al, 2017).…”

“…After data mining our previously published transcriptome, a pear BBX gene, namely PpBBX16, was found to be differentially expressed in pear fruit after they were removed from bags, and PpBBX16 may be involved in anthocyanin biosynthesis (Bai et al, 2017). In this work, the expression and function of the PpBBX16 gene were analysed.…”

Retrotransposon promoter of Ruby1 controls both light‐ and cold‐induced accumulation of anthocyanins in blood orange

“…Numerous studies have demonstrated that light is a major environmental factor affecting anthocyanin biosynthesis in plants. Accumulation of anthocyanins in fruits in response to light is mediated by a R2R3 MYB transcription factor in many plants including apple, litchi, pear, Chinese bayberry, and eggplant (Bai et al, ; M. Jiang, Ren, Lian, Liu, & Chen, ; Lai et al, ; Niu et al, ; Takos et al, ). HY5 is a basic leucine zipper (bZIP) transcription factor involved in light‐induced anthocyanin biosynthesis by directly binding to the G‐box motif within the promoter of R2R3 MYB regulators of anthocyanin biosynthesis and promoting anthocyanin accumulation (An et al, ; M. Jiang et al, ; Qiu et al, ; Shin et al, ).…”

“…that light is a major environmental factor affecting anthocyanin biosynthesis in plants. Accumulation of anthocyanins in fruits in response to light is mediated by a R2R3 MYB transcription factor in many plants including apple, litchi, pear, Chinese bayberry, and eggplant (Bai et al, 2017;M. Jiang, Ren, Lian, Liu, & Chen, 2016;Lai et al, 2014;Niu et al, 2010;Takos et al, 2006).…”