Background: Saline-alkali stress is a major factor limiting the growth of oats. Sugar is the primary carbon and energy source in plants which regulates plant development and growth by regulating enzyme activity and gene expression. Sucrose, glucose, and fructose are ubiquitous plant-soluble sugars that act as signalling molecules in the transcriptional regulation of various metabolic and defence-related genes.
Methods: In this study, soluble sugars, fructose, sucrose, and starch contents were measured, and transcriptomics was used to determine the differentially expressed genes (DEGs) in saline-sensitive and saline-tolerant oats after 6, 12, 24, and 48 h. DEGs annotated to carbohydrates were selected using the Kyoto Encyclopedia of Genes and Genomes.
Results: DEGs involved in carbohydrate metabolism were mainly enriched in the glycolysis/gluconeogenesis and pentose phosphate pathways, fructose and mannose metabolism, and starch and sucrose metabolism. GAPDH, SUPI, SUS2, ATP-PEK, HXK6, FBA4, TBA4, TKT, ISA3, PPDK1, and BAM2 were significantly expressed, and a quantitative reverse transcription polymerase chain reaction verified the transcriptome sequencing results.
Conclusions: In this study, oats with different salinity tolerances were used to determine sugar contents under four salinity stress durations, and transcriptome sequencing was used to explore the regulatory mechanism of sugars and provide a reference for elucidating the sugar signalling regulatory mechanism under abiotic stress.
Keywords: abiotic stress; carbohydrate metabolism; oats; saline-alkali stress; soluble sugars; transcriptomics.