Transcriptome and metabolome conjoint analysis revealed that PaGLK affects photosynthesis and composition of root exudates in poplar

Abstract

Background Photosynthetic carbon fixation is the main source of root exudates. GOLDEN2-LIKE (GLK) genes play an important role in photosynthetic carbon fixation. Previous studies have found that expression-inhibited the PaGLK in poplar reduce its net photosynthesis. However, the relationship between GLK genes, root exudates and photosynthetic carbon fixation and how photosynthesis affects root exudate in poplar are not clear. Result In this study, we performed comparative transcriptome and metabolome analyses of overexpression and suppression transgenic poplar. GO enrichment analysis showed that the downregulation of differentially expressed genes (DEGs) in suppression lines was mainly related to photosynthesis in biological processes. Specifically, photosynthesis-antenna proteins, porphyrin and chlorophyll metabolism, and photosynthesis were significantly enriched in KEGG pathways. Gene expression showed consistent trends in real time quantitative PCR (RT-qPCR) and transcriptome, indicating reliable transcriptome. Differentially expressed metabolites (DEMs) of root exudates were mainly enriched in amino acid metabolism, glucose metabolism and fatty acid metabolism pathways. After correlating DEGs and DEMs, we found that most genes and metabolites showed positive regulation. Conclusion This study shows that the new factors change composition of root exudates.