Transcriptome Characteristics of Endangered Plant Rhododendron jingangshanicum Tam based on RNA-Seq Analysis

Rhododendron jingangshanicum Tam is an alpine ornamental plant with high ornamental and application value.It faces survival threats due to habitat destruction and human disturbance.In order to explore the molecular basis of environmental adaptation and thereby enhance the conservation and effective utilization of the germplasm resources.In this study,we performed transcriptome sequencing of R.jingangshanicum Tam samples along an elevational gradient(1068—1787 m).A total of 230768 Unigenes were assembled,of which 55.23%(127455)were annotated in the NR database,51605 and 48401 were annotated by GO and KEGG databases,respectively.Functional analysis showed that plant-pathogen interactions,MAPK signaling and oxidative phosphorylation were significantly enriched.A total of 34714 DEGs were identified by differential expression analysis.Among them,RJ1345 vs RJ1504 and RJ1068 vs RJ1787 showed high transcriptome variations,while RJ1504 vs RJ1682 showed significantly fewer DEGs(1385),suggesting that the response of gene expression to elevation showed non-linear characteristics.A total of 2906 transcription factors were predicted in the transcription factor family,bHLH(9.87%)and MYB-related(8.01%)family members were the most.A total of 67541 SSR sites were detected by SSR locus analysis,mainly A/T(43.59%)and AG/CT(34.31%)repeats.The results of this study enriched the genetic information of R.jingangshanicum Tam,and provided a theoretical basis for the subsequent research on the analysis of species genetic diversity and the formulation of effective genetic resource protection strategies.