Title : Integrated metabolomics and transcriptomics analysis of exogenous arginine mediated sucrose accumulation in sugarcane
Abstract:
In order to clarify how arginine (Arg) regulates sugar metabolism in sugarcane and identify key genes associated with sucrose accumulation. A screening experiment was conducted by spraying L-arginine hydrochloride on the leaves and leaf sheaths of YZ05-51, YZ08-1609, and YT93-159 sugarcane varieties, which represent differences in sucrose metabolism. We found that YZ05-51 had a relatively higher effect of increasing sugar content. After spraying arginine with different pH values and concentrations on YZ05-51, transcriptome and metabolome experiments demonstrated that the optimal application of 20g/mu Arg at a pH of 7.0 significantly increased the sucrose content in stems of YZ05-51. We also identified key metabolites and related genes associated with starch and sucrose metabolism, glycolysis/gluconeogenesis, amino sugar, nucleotide sugar metabolism, and ATP-binding cassette (ABC) transporter pathways. Metabolomics analysis detected 32 sugar metabolites across three major categories, of which 25 were identified as differentially abundant metabolites (DAMs), including glucose, galactose, fructose, mannose, ribose, xylulose, and arabitol, and these metabolites increased efficiency of sucrose synthesis and accumulation in 'YZ 05-51', which promotes the conversion of other sugars into sucrose. Through integrated metabolomics and transcriptomics analysis, Key genes such as SBEs (starch branching enzymes) and TPS1 (trehalose-6-phosphate synthase) were identified, which may regulate sucrose synthesis by modulating carbon flux from starch metabolism and hexose allocation, and at the same time, GTs, RBSK, α-amylasses, LPH, MGAM, PGAM2, GH28, TPI, TIM10/TIM12, and peptide transporters genes, were identified as putatively involved in Arg-mediated sucrose conversion and transport in YZ05-51. This study provides valuable insights into the molecular mechanisms and critical role of Arg-mediated sucrose accumulation in sugarcane.
