Figure 3. Heatmap showing the effects of exogenous melatonin treatment and Pst DC3000 infection on the endogenous levels of 18 sugars and 5 sugar alcohols.

For exogenous melatonin treatments, 28-day-old of soil-grown WT (Col-0) Arabidopsis plants were watered with nutrient solution containing 20 μM melatonin from below in pots with plants. For pathogen infection, 28-day-old soil-grown WT (Col-0) Arabidopsis plant leaves were infected with bacterial suspension (OD₆₀₀ = 0.002) containg 10 mM MgCl₂ and 0.05% silwet L-77. For cluster analysis, all these metabolite levels were quantified as log₂ value of fold change in relative to the WT plants at 0 hr of treatment which was set as 1.0. The detailed concentrations were shown in Table 1. The asterisk (*) indicates significant difference in comparison to 0 hr of treatment at p < 0.05.