Genome-wide identification of abscisic acid(ABA) receptor pyrabactin resistance 1-like protein(PYL) family members and expression analysis of PYL genes in response to different concentrations of ABA stress in Glycyrrhiza uralensis

As abscisic acid(ABA) receptor, the pyrabactin resistance 1-like(PYR/PYL) protein(named PYL for simplicity) plays an important part to unveil the signal transduction of ABA and its regulatory mechanisms. Glycyrrhiza uralensis, a drought-tolerant medicinal plant, is a good model for the mechanism analysis of ABA response and active compound biosynthesis. However, knowledge about PYL family in G. uralensis remains largely unknown. Here, 10 PYLs were identified in G. uralensis genome. Characterization analysis indicated that PYLs in G. uralensis(Gu PYLs) are relatively conserved. Phylogenetic analysis showed that Gu PYL1-3 belongs to subfamily I, Gu PYL4-6 and Gu PYL10 belong to subfamily II and Gu PYL7-9 belongs to subfamily III. In addition, transcriptome data presented various expression levels of Gu PYLs under different exogenous ABA stresses. The expression pattern of Gu PYLs was verified by Quantitative real-time polymerase chain reaction(q RT-PCR). The study proved that Gu PYL4, Gu PYL5, Gu PYL8 and Gu PYL9 genes are significantly up-regulated by ABA stress and the response process is dynamic. This study paves the way for elucidating the regulation mechanism of ABA signal to secondary metabolites and improving the cultivation and quality of G. uralensis using agricultural strategies.