Fig.1

Functional analysis of polyamines in F. graminearum infection and Deoxynivalenol (DON) production on wheat. a Schematic diagram of putrescine, spermidine, and spermine biosynthesis in plants. SPDS and SPMS are responsible for the transfer of aminopropyl groups to spermidine and spermine, respectively. ADC, arginine decarboxylase; SPDS, spermidine synthase; SPMS, spermine synthase; dc-SAM, decarboxylated S-adenosylmethionine; ADC, ornithine decarboxylase. b DON production in trichothecene biosynthesis-inducing (TBI) medium with glutamine (Gln), arginine (Arg), ornithine (Orn), agmatine (AGM), putrescine (Put), spermidine (Spd), and spermine (Spm) as the sole nitrogen source. DW, Dry weight. The error bar represents standard errors (SEs) from three independent replicates (n = 3). Different letters indicate significant differences based on ANOVA analysis followed by Duncan’s multiple range test (P = 0.05). c Representative images of polyamine-treated wheat head with F. graminearum inoculation. d Diseased spikelet number of polyamine-treated and F. graminearum infected wheat. e DON levels of polyamine-treated and F. graminearum infected wheat. The error bar indicates standard errors of the means (n varies for each column and is shown in each case directly on the graphs). P-values are from the Student’s t-tests