Transcriptome analysis of diploid and triploid Populus tomentosa

PeerJ. 2020 Oct 28:8:e10204. doi: 10.7717/peerj.10204. eCollection 2020.

Abstract

Triploid Chinese white poplar (Populus tomentosa Carr., Salicaceae) has stronger advantages in growth and better stress resistance and wood quality than diploid P. tomentosa. Using transcriptome sequencing technology to identify candidate transcriptome-based markers for growth vigor in young tree tissue is of great significance for the breeding of P. tomentosa varieties in the future. In this study, the cuttings of diploid and triploid P. tomentosa were used as plant materials, transcriptome sequencing was carried out, and their tissue culture materials were used for RT-qPCR verification of the expression of genes. The results showed that 12,240 differentially expressed genes in diploid and triploid P. tomentosa transcripts were annotated and enriched into 135 metabolic pathways. The top six pathways that enriched the most significantly different genes were plant-pathogen interaction, phenylpropanoid biosynthesis, MAPK signalling pathway-plant, ascorbate and aldarate metabolism, diterpenoid biosynthesis, and the betalain biosynthesis pathway. Ten growth-related genes were selected from pathways of plant hormone signal transduction and carbon fixation in photosynthetic organisms for RT-qPCR verification. The expression levels of MDH and CYCD3 in tissue-cultured and greenhouse planted triploid P. tomentosa were higher than those in tissue-cultured diploid P. tomentosa, which was consist ent with the TMM values calculated by transcriptome.

Keywords: GO categories; KEGG categories; Populus tomentosa; RT-qPCR analysis; Transcriptome analysis.

Grants and funding

The project was supported by the National key R & D Plan for the 13th Five-Year Plan Project of China (Grant No. 2016YFD0600102) and the National Natural Science Foundation of China (Grant No. 31760450). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.