Transcriptomic Characterization of Miscanthus sacchariflorus × M. lutarioriparius and Its Implications for Energy Crop Development in the Semiarid Mine Area

Abstract

Miscanthus interspecific hybrids have been proved to have better adaptability in marginal lands than their parents. Miscanthus sacchariflorus and Miscanthus lutarioriparius were used as the parents to develop hybrids. We performed the transcriptome for 110 F1 hybrids of Miscanthus sacchariflorus × Miscanthus lutarioriparius and their parents that had been established on the Loess Plateau mine area, to estimate the population's genetic expression variation, and illuminate the adaptive mechanism of the F1 population. The result speculated that the F1 population has mainly inherited the stress response metabolic pathway of its female parent (M. sacchariflorus), which may be responsible for its higher environmental adaptability and biomass yield compared with male parents. Based on PopART, we assembled a leaf reference transcriptome for M. sacchariflorus (LRTMS) and obtained 8116 high-quality transcripts. When we analyze the differential expression of genes between F1 population and parent, 39 and 56 differentially expressed genes were screened out in the female parent and male parent, respectively. The enrichment analysis showed that pathways of carbohydrate metabolism, lipid metabolism, biosynthesis of secondary metabolites and circadian rhythm-plant played a key role in resisting the harsh environment. The carbohydrate metabolism and lipid metabolism were also significantly enriched, and the synthesis of these substances facilitated the yield. The results provided an insight into breeding Miscanthus hybrids more suited to the harsh environment of the Loess Plateau.

Keywords: Miscanthus lutarioriparius; Miscanthus sacchariflorus; metabolic pathways; transcriptome analysis.

Figure 1

The FPKM Distribution Comparing F1 Population and Parents. The red line demonstrates the range of the FPKM distribution between 0 and 50 in the hybrid. The green line demonstrates the range in the FPKM distribution between 0 and 50 in M. sacchariflorus. The blue line demonstrates the range of the FPKM distribution between 0 and 50 in M. lutarioriparius.

Figure 2

The Volcano Plots of Differential Expression Genes. Blue dots on the right represent up-regulated DEGs and blue dots on the left represent down-regulated DEGs.

Figure 3

The Analysis of Differential Expression Genes in Three Differential Groups. The sum of the numbers in each large circle represents the total number of DEGs between combinations. The overlapping part of the circles represents DEGs for the treatment combinations. “DEG1”: number of DEGs between M. sacchariflorus and M. lutarioriparius; “DEG2”: number of DEGs between hybrids and M. lutarioriparius; “DEG3”: number of DEGs between hybrids and M. sacchariflorus.

Figure 4

Clustering of Expression of Differential Expression Genes between F1 vs. M. sacchariflorus.

Figure 5

Clustering of Expression of Differential Expression Genes between F1 vs. Male parent.

Figure 6

GO Enrichment of Expression of Differential Expression Genes between F1 vs. Female parent. The statistically significant difference of GO enrichment of expression of differential expression genes is marked as .

Figure 7

GO Enrichment of Expression of Differential Expression Genes between F1 vs. Male parent. The statistically significant difference of GO enrichment of expression of differential expression genes is marked with .

Figure 8

KEGG Enrichment of Expression of Differential Expression Genes between F1 vs. Female parent.

Figure 9

KEGG Enrichment of Expression of Differential Expression Genes between F1 vs. Male parent.

Figure 10

Locations of Pingliang City in Gansu Province (PG, red pot, 37.12° N, 111.45° E), Changsha City in Hunan Province (CH, green pot, 28.12° N, 112.59° E) and Lvliang City in Shanxi Province (LS, yellow pot, 35.19° N, 107.23° E) of China.