Genome-Wide Identification of Long Non-Coding RNAs and Their Potential Functions in Poplar Growth and Phenylalanine Biosynthesis.

Xingqi Cheng,Jianjun Hu,Xiaolan Ge,Lei Zhang,Xiaopeng Peng,Jiujun Du

doi:10.3389/fgene.2021.762678

Abstract

Poplar is an important bioenergy tree species. lncRNAs play important roles in various biological regulatory processes, and their expression pattern is more tissue-specific than mRNAs. In this study, P. deltoides “Danhong” (Pd) and P. simonii “Tongliao1” (Ps) with different growth rates and wood quality were used as experimental materials, and the transcriptomes of their shoot apical meristem, xylem, and phloem were sequenced. Furthermore, high-throughput RNA sequencing analysis revealed that the expression patterns of genes and lncRNAs are different between the two genotypes. 6,355 lncRNAs were identified. Based on target prediction, lncRNAs and target genes were involved in ADP binding, oxidoreductase activity, phenylpropanoid biosynthesis, and cyanoamino acid metabolism. The DElncRNAs in two poplars were co-expressed with transcription factors and structural genes of lignin and flavonoid pathways. In addition, we found the potential target lncRNAs of miRNA. This result provides basic evidence for a better understanding of the regulatory role of lncRNAs in regulating phenylalanine molecular pathways and wood formation.

Highlights

Plants are unique in their ability to continuously produce new organs throughout their life cycles
The slice results showed that the shoot apical meristem (SAM) was surrounded by young leaves, and the SAM of P. simonii “Tongliao1” (Ps). deltoides “Danhong” (Pd) was conical and convex, while the Ps was flat, which suggested that the growth point of Ps might not be obvious enough, which caused the high growth to be slower (Figure 1C)
The radial section of the stem showed that the phloem of Pd had wider phloem fibers, and the cambium was more obvious (Figure 1D)

Summary

Introduction

Plants are unique in their ability to continuously produce new organs throughout their life cycles. The process of continuous organogenesis depends on the activity of pluripotent cells (Xue et al, 2020). In trees, this mainly refers to the shoot apical meristem (SAM) affecting high growth and the vascular cambium affecting radial growth (Elo et al, 2009). The cambium differentiates into xylem and phloem, determined cell types, and cell layers in the secondary xylem (Ye and Zhong, 2015). These complex processes are regulated by plant hormones, transcription factors (TFs), miRNAs, and lncRNAs These complex processes are regulated by plant hormones, transcription factors (TFs), miRNAs, and lncRNAs (J. Zhang G. et al, 2018; Xue et al, 2020)

Methods

Results

Conclusion