Transcriptional Analysis of Masson Pine (Pinus massoniana) under High CO2 Stress

Abstract

To explore the molecular mechanism of the response of Masson pine (Pinus massoniana), the main coniferous tree in southern China, to high CO2 stress, transcriptome sequencing was carried out to analyze the genome-wide responses of annual seedlings under different durations (0 h, 6 h, 12 h and 24 h) of high CO2 stress. The results showed that a total of 3080/1908, 3110/2115 and 2684/1483 genes were up-/down-regulated after 6 h, 12 h and 24 h of treatment, respectively, compared with control check group (CK, 0 h). Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that most of these differentially expressed genes (DEGs) were enriched in energy metabolism, carbohydrate synthesis, cell wall precursor synthesis and hormone regulation pathways. For energy metabolism, the expression of most genes involved in photosynthesis (including the light reaction and Calvin cycle) was generally inhibited, while the expression of genes related glycolysis, the tricarboxylic acid (TCA) cycle and PPP pathway was up-regulated. In addition, the increase in the CO2 concentration induced the up-regulation of gene expression in the sucrose synthesis pathway. Among all starch synthesis genes, GBSS (granule-bound starch synthase) had the highest expression level. On the other hand, during the synthesis of hemicellulose and pectin (cell wall precursor substances), the expression levels of GMD (GDP-mannose 4,6-dehydratase), MGP (Mannose-1-phosphate guanylyl transferase) and RHM (Rhamnose biosynthetic enzyme) were the highest, suggesting that the synthesis of the raw materials hemicellulose and pectin in Masson pine under stress were mainly supplied by GDP-Man, GDP-Fuc and UDP-Rha. Finally, stress inhibited gene expression in the ABA (Abscisic Acid) synthesis pathway and induced gene expression in the GA (Gibberellin), SA (Salicylic acid), BR(Brassinolide) and MeJA (Methyl Jasmonate) pathways. Stomatal switches were regulated by hormonal interactions. This experiment elaborated on the response and molecular mechanism of Masson pine to CO2 stress and aided in screening carbon sequestration genes for the corresponding molecular research of Masson pine in the future.

Identification, classification, and characterization of AP2/ERF superfamily genes in Masson pine (Pinus massoniana Lamb.)

“…The lack of reference genomic data has limited Masson pine research. Transcriptome sequencing is a feasible and economical technique for generating relatively comprehensive sequencing data within a short time, and this technique has become popular in plant research 19 , 28 . Previous studies have demonstrated that the AP2 / ERF gene family is one of the most abundant transcriptional factor families in Masson pine 19 , 33 .…”

“…Masson pine ( Pinus massoniana ) is an economically and ecologically important evergreen conifer in southern China and is one of the most important forest tree species 18 , 19 . It is widely used in the production of solid wood and resin 20 .…”

Transcriptome-Wide Identification of WRKY Transcription Factors and Their Expression Profiles under Different Types of Biological and Abiotic Stress in Pinus massoniana Lamb

“…Transcriptome data for Masson pine were derived from the previously determined CO 2 stress transcriptome [ 15 ] and young shoots transcriptome (PRJNA655997). Based on the WRKY domain (PF03106), the hidden Markov model file was downloaded from the Pfam protein family database.…”

“…Air containing approximately twice the CO 2 concentration in the chamber before the experiment was aerated into the growth chamber constantly for at least 24 h. The CO 2 concentration in the chamber was monitored by an infrared CO 2 analyzer (SenseAir, Delsbo, Sweden). The seedlings were sampled after 6 h, 12 h and 24 h of treatment with the high CO 2 concentration [ 15 ]. For each treatment, leaves collected from three triangular bottles were sampled as three biological replicates for RNA-seq.…”

Identification and Characterization of the Basic Helix-Loop-Helix Transcription Factor Family in Pinus massoniana

“…bHLH sequences of A. thaliana were downloaded from the Plant Transcription Factor database (http://planttfdb.cbi.pku.edu.cn/). Transcriptome data for Masson pine were derived from the previously determined CO 2 stress transcriptome [27], drought stress transcriptome (PRJNA595650), pine wood nematode inoculation transcriptome (PRJNA660087) and young shoots transcriptome (PRJNA655997). A Markov model (HMM) was used to screen out the bHLH gene files from the four transcriptomes by the hmmsearch program (HMMER 3.0).…”