Identification of key genes related to flowering by transcriptome of flowering and nonflowering Prunella vulgaris

Prunella vulgaris L. is known as ‘Xiaku-cao’, because it withers and dies after the summer solstice (Chen et al. 2013). It is a perennial herb in the family Lamiaceae, and its dried spicas are used in medicine (Liao et al. 2012). The Pharmacopoeia of the People’s Republic of China (2020) states that P. vulgaris has drug efficacy in removing liver-fire for improving eyesight, subsiding swelling to dissipate indurated mass. Modern research shows that P. vulgaris contains a variety of chemical constituents, such as phenylpropanoids, flavonoids, triterpenes, organic acids, sugars, coumarins, and steroids (Bai et al. 2016). Studies show that P. vulgaris exerts antitumour (Feng et al. 2010), anti-inflammatory (Hwang et al. 2013), and hypoglycaemic activity (Raafat et al. 2016). In addition, the use of P. vulgaris in herbal tea has been continuously developed, resulting in high demand. Flowering P. vulgaris