| Low temperature is one of abiotic stress that can affect the growth and yield.So it is important for us to understand how the wheat can defend themselves against the cold at molecular and biochemical level.To gain insights into the changes in genes and metabolites after treated at 4℃cold acclimation 28d and-5℃freezing 24h for Jing411,we integrated the transcriptome and metabolome in this study.The main results were as follows:1.Targeted metabolomics technique was used to study the metabolites changes in the crown of Jing411 when the seedings subjected to low temperature acclimation at 4°C for28 days and-5°C for 24h.The results showed that a total of 223 differentially expressed metabolites were found in the comparison of LTA and NTG,of which 86 were up-regulated and 137 were down-regulated.Differential metabolites mainly include sugars,flavonoids,organic acids and plant hormones.There were significant changes in sugars,such as raffinose,trehalose,fructose,melezitose and mannose,among which raffinose had the largest fold change（129.44）;For amino acids,25 differentially accumulated metabolites were identified,of which proline has increased 11.81-fold.KEGG analysis showed that“Arginine and proline metabolism”,“Galactose metabolism”and“Biosynthesis of plant secondary metabolites”were significantly enriched by differentially expressed metabolites under cold treatment.By comparing the differentially metabolisms in LTAF vs LTA and NTGF vs NTG respectively,we found there are 8 common differentially expressed metabolites,including abscisic acid and Ja-Ile and the exogenous ABA can improve the freezing tolerance.2.RNA-seq technique was used to study the transcriptomes of Jing411 crown samples treated with 4°C for 28 days and-5°C for 24h.Transcriptome analysis revealed that 4°C cold acclimation altered the expression of 29066 genes,among which 108 DEGs|log2FoldChange|>7.The functions of DEGs inclucing cold-related proteins,Chlorophyll A-B binding protein,signal transport preoteins and transcription factors.By comparing the differentially expressed genes in LTAF vs LTA and NTGF vs NTG respectively,we found some genes related with transcription factor,Ca2+signaling and cold-related protein.Differentially expressed genes are mainly involved in Metabolic pathways,Starch and sucorse metabolism,Plant hormone signal transduction and Biosynthesis of secondary metabolites.3.Combined transcriptome and metabolome analyses to characterize the cold stress responses in wheat.DEGs and DEMs can be integrated into multiple metabolic pathways,among which“Arginine and proline metabolism”attracting our attention.Up-regulated of P5CR,P5CS gene and down-regulated of ProDH that making the proline content increased significantly,indicating that proline plays an important role in cold stress response.In summary,there are many genes and metabolites can be identified which responded to low temperature were detected in this study. |
