RNA-Seq Reveals Transcription Factors Involved in Temperature-mediated Anthocyanin Accumulation and Biosynthesis in Purple Pakchoi (Brassica campestris ssp. Makino.)

Temperature is a main environmental factor that affects anthocyanin biosynthesis and accumulation in purple pakchoi (Brassica campestris ssp. Chinensis Makino.). Purple pakchoi is one of the most popular vegetables with high content of anthocyanin in China. Recently, we found that the purple color of purple pakchoi cultivar, "ziyi", deepened after 10-day low temperature(5°C, LT) treatment with increased anthocyanin content compared to plants after 20°C (normal temperature, NT, control) treatment. Contractly, the color of pakchoi treated with 10-day heat temperature (35°C, HT) became lighter with decreased anthocyanin content than that of control. The transcriptiom analysis revealed a total of 51008 unigenes from plants treated with NT，LT, and HT by RNA-seq. A total of 4321 and 8455 differentially expressed genes (DEGs) were identified from HT and LT compared to NT, respectively. Among these DEGs, 173 unigenes were downregulated in LT and upregulated in HT compared to NT. 218 unigenes were upregulated in LT and downregulated in HT. Further Gene Ontology enrichment analysis revealed a series of candidate genes that may be involve in temperature-mediated anthocyanin accumulation, including structural genes and 20 transcription factors. Collectively, our study provide a global view of transcriptiomic resources in response to temperature-induced anthocyanin accumulation in purple pakchoi.