SUPPORTING INFORMATION Figure S1. Seed germination after ageing at room temperature conditions. Figure S2. Reduced TTC levels in elm seeds stained during CDT. Figure S3. Variation analysis of morphology and mobility in different categories of mitochondria. A and B: mitochondria one-dimensional length. A: Red fluorescence, mitochondria labeled with MitoTracker. B: Box plots statistics displaying variation in samples of a statistical population. The spacings between the different parts of the box indicate the degree of dispersion (spread) and skewness in the data, and show outliers. Measurements were made on 100 individual mitochondria. C and D: mitochondrial motion distance. Red fluorescence, mitochondria labeled with MitoTracker at the 0s; Green fluorescence, pseudo-color indicating MitoTracker labeled mitochondria moved for 30s. Figure S4. The purity of mitochondria isolated from elm seeds using Percoll density gradient. For the gradients, 1 mL of each fraction was collected and analyzed for marker enzyme activities of mitochondria (cytochrome c oxidase), peroxisomes (catalase), cytosol (alcohol dehydrogenase), and plastids (alkaline pyrophosphatase). Enzyme activity was expressed in units per milligram protein. Figure S5. Changes in Rh123 fluorescence energised by succinate and NADH from elm seed mitochondria isolated during CDT. Figure S6. Quantitative analysis of western blotting. Table S1. The effect of mitoTEMPO on elm seed germination. MitoTEMPO pretreatment was performed for 12h at 4 ℃ before CDT without the radical outstretched and then redried to the original MC under air and then aged until the untreated seeds had lost 50% viability (3 d). Data are expressed as means ± SE from three experiments. Non-pretreated, seeds without mitoTEMPO pretreatment; Water, seeds pretreated with H2O. Table S2. Changes in mitochondrial antioxidant enzyme activity of elm seeds during CDT. The data are expressed as means ± SE from three experiments. CAT, catalase; GR, glutathione reductase; MnSOD, manganese superoxide dismutase. Table S3. The effect of AsA on elm seed germination. AsA pretreatment was performed for 12 h at 4 ℃ before CDT without the radical outstretched and then redried to the original MC under air and then aged until the untreated seeds had lost 50% viability (3 d). Data are expressed as means ± SE from three experiments. Non-pretreated, seeds without AsA pretreatment; Water, seeds pretreated with H2O. Table S4. The effect of CsA on elm seed germination. CsA pretreatment was performed for 12 h at 4 ℃ before CDT without the radical outstretched and then redried to the original MC under air and then aged until the untreated seeds had lost 50% viability (3 d). Data are expressed as means ± SE from three experiments. Non-pretreated, seeds without CsA pretreatment; Water, seeds pretreated with H2O. Table S5. Primers used in semi-quantitative RT-PCR. Table S6. Antbodies and dilutions used. Word count: 240