nt evaluation from the DEGs associated to terpenoid biosynthesis (d), phenylpropanoid biosynthesis (e) and plant hormone signal transduction (f). The cIAP review considerable p value of each and every KEGG term in the two comparisons had been shown by heatmaps. The bar indicated the important valuesIn Taxus sp., the precursor in the diterpenoid taxane core, geranylgeranyl diphosphate (GGPP), is synthesized in the C5 isoprenoid precursor IPP and DMAPP, which are produced by the plastid-localized plastidial 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway [34]. So analysis the change of genes involved in terpenoid biosynthesis and taxol biosynthesis soon after KL27-FB treatment is useful 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 had been mapped within the ERRĪ² Compound RNA-seq information of T. chinensis needles, and several unigenes corresponding to these genes were presented and showed up-regulated right after KL27-FB stimuli (Fig. 4b). Specifically, two genes encoding the two enzymes catalyze the slow measures of the MEP pathway, DXS and DXR were substantially up-regulated soon after KL27-FB treatment (Fig. 4b), indicated that KL27-FB elicitor could enhance the precursor provide for diterpenoid taxane core synthesis in taxol biosynthesis pathway.Cao et al. BMC Plant Biology(2022) 22:Web page eight ofKL27FB effected phenylpropanoid biosynthesisKL27FB activated the taxol biosynthesis pathwayPhenylpropane biosynthesis is one of the most important secondary metabolic pathways in plants, producing much more than 8000 metabolites, which plays an essential part in plant growth and development and plant-environmental interactions [35]. Within this study, based on KEGG analysis the substantial values of KEGG pathway “phenylpropanoid biosynthesis” (ko00940) were 8.79E-05 and 1.05E-12 at 0.5 h and six h after KL27-FB treatment options respectively, which showed that phenylpropanoid biosynthesis was substantially activated following KL27-FB elicitation (Fig. 3e). Our RNA-seq data also shown that 165 unigenes, which includes 62 and 81 DEGs at 0.5 h and 6 h right after KL27-FB elicitation respectively, had been annotated as phenylpropanoid biosynthesis members (Extra file 8). Among these unigenes, the expressions of 37 DEGs were up-regulated, and 25 DEGs had been down-regulated at 0.five h just after KL27-FB therapy. Though, the expressions of 42 DEGs had been up-regulated, and 39 DEGs have been down-regulated at 6 h soon after KL27-FB elicitor (Extra file 9). Genes related to key enzymes within the phenylpropanoids biosynthesis pathways [35], such as 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 soon after KL27-FB treatment options (More file 9). These benefits suggested that KL27-FB considerably affected the phenylpropanoid biosynthesis in T. chinensis needles. Also, The phenylpropanoid biosynthesis pathway supplies the C13-phenylpropanoid side chain for taxol biosynthesis. To supply insight into the effects of KL2-FB on the genes involved in each phenylpropanoid biosynthesis and taxol biosynthesis in T. chinensis needles. The expression pattern of PAM gene just after KL27-FB therapy with time was analyzed. As shown in Fig. 4b, the expression of a unigene (DN22851_c0g1i1.2) corresponding to PAM were highly re