尾叶桉组培苗根系发育不同时期转录组分析

To study the differentially expressed genes(DEGs)in different periods during the root development of Eucalyptus urophylla tissue culture seedlings,providing data basis for mining functional genes related to rooting of Eucalyptus urophylla.A tissue culture clone(E)of E.urophylla was used as the material.According to the morphological changes of the base during root development,2 mm materials at the base of 0d(E0),1d(E1),4d(E4)and 6d(E6)were selected for transcriptome sequencing analysis.Gene differential expression analysis,GO analysis and KEGG analysis were used to obtain candidate functional genes that promote root development of E.urophylla.A total of 7944 DEGs were obtained,among which E1(root development 1d)had the highest number of DEGs compared with control(E0),with a total of 5902 DEGs.The second was E4 vs E1 with 2840 DEGs.E4 vs E1 had the least DEGs(1094).GO analysis showed that DEGs were significantly involved in metabolic processes,cellular processes and biological regulation,with the function of catalytic activity and binding functions 1 day after transfer to IBA medium.KEGG analysis showed that DEGs of E1 vs E0 was significantly enriched in ribosome,glutathione metabolism and phenylpropanoid biosynthesis.DEGs of E4 vs E1 were significantly enriched in biosynthesis of other secondary metabolites and folding,sorting and degradation.The DEGs of E6 vs E4 were significantly enriched in phenylpropanoid biosynthesis,biosynthesis of secondary metabolites,and cutin,suberine and wax biosynthesis.Further KEGG analysis of up-regulated DEGs at different periods showed that E1vs E0 up-regulated DEGs were mainly enriched in five pathways,and a total of 40 DEGs were significantly enriched in plant hormone signal transduction(P<0.01,Q<0.05),mainly including AUX1,AUX/IAA,ARF,SAUR in auxin signal transduction pathway,CRE1,AHP,A-ARR in cytokinine signal transduction pathway,GID,DELLA,TF in gibberellin signal transduction pathway.The up-regulated DEGs of E4 vs.E1 were significantly enriched in protein processing in endoplasmic reticulum,phenylpropanoid biosynthesis and glutathione metabolism pathway.The up-regulated DEGs of E6 vs.E4 were significantly enriched in the pathways of phenylpropanoid biosynthesis,biosynthesis of secondary metabolites and protein processing in endoplasmic reticulum.In the libraries of E6 vs.E4 and E4 vs.E1,16 and 25 DEGs were up-regulated and significantly enriched in phenylpropanoid biosynthesis,which may be involved in the biosynthesis process of root cell wall.A total of 57 DEGs of E4 vs.E1 were up-regulated and significantly enriched in endoplasmic reticulum protein processing.The high expression of these genes indicating that they may provide materials for the biosynthesis of root cell membranes.The number of DEGs of E.urophylla decreased gradually after being transferred to rooting medium,indicating that 1d on IBA medium was the key period for root initiation and development.The expression patterns of auxin,gibberellin and cytokinin signal transduction pathways showed an upward trend during the initiation period,indicating that the initiation of root system was regulated by plant hormones.In the root growth period,the genes related to phenylpropanoid biosynthesis and endoplasmic reticulum protein processing were up-regulated,indicating that these genes may be involved in the biosynthesis of root cell wall and cell membrane.