nt analysis in the DEGs connected to terpenoid biosynthesis (d), phenylpropanoid biosynthesis (e) and plant hormone signal transduction (f). The significant p value of each KEGG term within the two comparisons have been shown by heatmaps. The bar indicated the important valuesIn Taxus sp., the precursor in the diterpenoid taxane core, geranylgeranyl diphosphate (GGPP), is synthesized from the C5 isoprenoid precursor IPP and DMAPP, which are created by the plastid-localized plastidial K-Ras drug 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway [34]. So analysis the adjust of genes involved in terpenoid biosynthesis and taxol biosynthesis right after KL27-FB treatment is helpful to investigate the molecular mechanism of taxol accumulation responding to KL27-FB stimuli in T. chinensis needles. Genes involved in thebiosynthesis of IPP and DMAPP by MEP pathway were mapped in the RNA-seq data of T. chinensis needles, and various unigenes corresponding to these genes have been presented and showed up-regulated after KL27-FB stimuli (Fig. 4b). Specially, two genes encoding the two enzymes catalyze the slow methods of your MEP pathway, DXS and DXR were significantly up-regulated following KL27-FB treatment (Fig. 4b), indicated that KL27-FB cIAP-2 Accession elicitor could boost the precursor provide for diterpenoid taxane core synthesis in taxol biosynthesis pathway.Cao et al. BMC Plant Biology(2022) 22:Web page 8 ofKL27FB effected phenylpropanoid biosynthesisKL27FB activated the taxol biosynthesis pathwayPhenylpropane biosynthesis is one of the most important secondary metabolic pathways in plants, generating more than 8000 metabolites, which plays an important function in plant growth and development and plant-environmental interactions [35]. In this study, determined by KEGG evaluation the substantial values of KEGG pathway “phenylpropanoid biosynthesis” (ko00940) had been eight.79E-05 and 1.05E-12 at 0.5 h and six h following KL27-FB treatment options respectively, which showed that phenylpropanoid biosynthesis was significantly activated soon after KL27-FB elicitation (Fig. 3e). Our RNA-seq data also shown that 165 unigenes, such as 62 and 81 DEGs at 0.5 h and six h following KL27-FB elicitation respectively, had been annotated as phenylpropanoid biosynthesis members (Extra file eight). Amongst these unigenes, the expressions of 37 DEGs had been up-regulated, and 25 DEGs have been down-regulated at 0.5 h right after KL27-FB therapy. Even though, the expressions of 42 DEGs have been up-regulated, and 39 DEGs were down-regulated at 6 h soon after KL27-FB elicitor (Added file 9). Genes related to important enzymes inside the phenylpropanoids biosynthesis pathways [35], like phenylalanine ammonia-lyase (PAL), PAM, 4-coumarate CoA ligase (4CL), trans-cinnamate 4-monooxygenase, caffeic acid 3-O-methyltransferase (COMT), shikimate O-hydroxy cinnamoyltransferase (HCT), p-coumarate 3-hydroxylase (C3’H) et. al have been differently expressed in T. chinensis needles right after KL27-FB remedies (Extra file 9). These outcomes suggested that KL27-FB significantly affected the phenylpropanoid biosynthesis in T. chinensis needles. Furthermore, The phenylpropanoid biosynthesis pathway supplies the C13-phenylpropanoid side chain for taxol biosynthesis. To provide insight into the effects of KL2-FB on the genes involved in both phenylpropanoid biosynthesis and taxol biosynthesis in T. chinensis needles. The expression pattern of PAM gene following KL27-FB treatment as time passes was analyzed. As shown in Fig. 4b, the expression of a unigene (DN22851_c0g1i1.2) corresponding to PAM have been hugely re