Background: Plant hormones not only participate in regulating the growth and development process of plants, but also play an important regulatory role in the synthesis of secondary metabolites. Prunella vulgaris L. (P. vulgaris) is a perennial herb that has a long history for use as a kind of medicinal and edible plant. In order to understand the relationship between plant hormones and Prunella vulgaris L. (P. vulgaris) development. Methods: The quantification of indoleacetic acid (IAA), salicylic acid (SA), jasmonates (JAs), abscisic acid (ABA), 1-aminocyclopropane-1-carboxylic acid (ACC) and cytokinins (CKs) of P. vulgaris during development was performed by a liquid chromatography-mass spectrometry (LC-MS). Furthermore, the effect of exogenous ABA on rosmarinic acid (RA) accumulation was verified. Results: Nuts formation was related to the concentrations of IAA, ABA and ACC in the green-fruit stage, and IAA and ABA levels increased rapidly in this stage. High IAA concentrations can promote an increase in ACC. SA, JAs, ethylene (ET) and ABA were related to the defence response of plants to pathogens. SA concentrations increased sharply after the turning stage, while the concentration of JAs, which are antagonistic to SA, was low. The decrease in ABA concentration after this period may be related to the antagonistic effect of IAA or SA. The CKs trans-zeatin (tZ) and trans-zeatin riboside (tZR) promoted the growth and development of early P. vulgaris, and their concentrations decreased in the late period, leading to withering and senescence of P. vulgaris. The CKs cis-zeatin (cZ) and N6-(2-isopentenyl) adenine (iP) were presumed to be present in nuts. After elicitation with 10 μg/mL ABA, an increase of RA content was observed (p < 0.05). Conclusion: This study can provide an improved basis for elucidating the growth and development mechanism of P. vulgaris in the future, as well as a better understand of the effects of ABA application on RA accumulations.
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