Transcription-associated metabolomic profiling reveals the critical role of frost tolerance in wheat

Abstract

Background: Low temperature is a crucial stress factor of wheat (Triticum aestivum L.) and adversely impacts on plant growth and grain yield. Multi-million tons of grain production are lost annually because crops lack the resistance to survive in winter. Particularlly, winter wheat yields was severely damaged under extreme cold conditions. However, studies about the transcriptional and metabolic mechanisms underlying cold stresses in wheat are limited so far. Results: In this study, 14,466 differentially expressed genes (DEGs) were obtained between wild-type and cold-sensitive mutants, of which 5278 DEGs were acquired after cold treatment. 88 differential accumulated metabolites (DAMs) were detected, including P-coumaroyl putrescine of alkaloids, D-proline betaine of mino acids and derivativ, Chlorogenic acid of the Phenolic acids. The comprehensive analysis of metabolomics and transcriptome showed that the cold resistance of wheat was closely related to 13 metabolites and 14 key enzymes in the flavonol biosynthesis pathway. The 7 enhanced energy metabolites and 8 up-regulation key enzymes were also compactly involved in the sucrose and amino acid biosynthesis pathway. Moreover, quantitative real-time PCR (qRT-PCR) revealed that twelve key genes were differentially expressed under cold, indicating that candidate genes POD, Tacr7, UGTs, and GSTU6 which were related to cold resistance of wheat. Conclusions: In this study, we obtained the differentially expressed genes and differential accumulated metabolites in wheat under cold stress. Using the DEGs and DAMs, we plotted regulatory pathway maps of the flavonol biosynthesis pathway, sucrose and amino acid biosynthesis pathway related to cold resistance of wheat. It was found that candidate genes POD, Tacr7, UGTs and GSTU6 are related to cold resistance of wheat. This study provided valuable molecular information and new genetic engineering clues for the further study on plant resistance to cold stress.