1. 20 o C35 o C Respiration Supplementary Table S1. Respiration rates of the mitochondria isolated from the florets of thermogenic male part of the spadices of D. vulgaris. State 2 38.2±19.1 78.4±50.8** State 3 31.7±21.6 121.4±23.3** O 2 uptake (nmol O 2 /min/mg protein) The rates of oxygen uptake were measured using an oxygen electrode cuvette after sequential addition of succinate (0.5 mM; state 2 respiration) and ADP (0.5 mM ADP; state 3 respiration) at either 20 o C or 35 o C. The data are expressed as the mean ± standard deviation (n = 3). Significant differences between the temperatures were evaluated by Student’s t-test and are shown as asterisks (**P < 0.01).

2. 20 o C35 o C (-Pyr) 36.1±6.8 92.2±11.9** (+Pyr) 48.4±6.4299.0±61.3** COX capacity24.6±8.0 55.9±1.6** AOX capacity Respiration Supplementary Table S2. Alternative and cytochrome respiration capacity of the mitochondria isolated from the florets of thermogenic male part of the spadices of D. vulgaris. O 2 uptake (nmol O 2 /min/mg protein) The rates of oxygen uptake by purified mitochondria were measured using an oxygen electrode cuvette at either 20 o C or 35 o C in the presence of 100 mM n-propyl gallate or 0.5 mM KCN for measurement of the alternative or cytochrome pathways, respectively. The capacity of the alternative oxidase (AOX) and cytochrome (COX) pathways was measured as described in the Materials and Methods. The results shown represent the mean ± standard deviation of three measurements using the mitochondria from the same preparation. Significant differences between the temperatures were evaluated by Student’s t-test and are shown as asterisks (**P < 0.01).

3. # aa ++ bb ++ b*b* b *++ AAyy ++ y*y* ++ # 188.039344.5233116.034258.5207D 21 2201.1234101.0653229.1183115.0628I2159.0771080.0422142.0501071.52920 3330.1660165.5866358.1609179.5841E2045.9931023.5002028.9661014.98719 4417.1980209.1026445.1929223.1001S1916.950958.97871899.924950.465418 5474.2195237.6134502.2144251.6108G1829.918915.46271812.892906.949417 6531.2409266.1241559.2358280.1216V1772.897866.95191755.870878.438716 7644.3250322.6661672.3199336.6636I1715.875858.44121698.849849.927915 8772.3836386.6954800.3785400.6929783.3519392.1796Q1602.791801.89921585.764793.385914 9887.4105444.2089915.4054458.2063898.3789449.6931D1474.732737.86991457.706729.356613 10974.4425487.72491002.437501.7224985.4109493.2091S1359.706680.35641342.679671.843112 111071.495536.25131099.490550.24871082.464541.7355P1272.674636.84041255.647628.327111 121142.532571.76981170.527585.76731153.501577.2540A1175.621588.31401158.594579.800710 131239.585620.29621267.580634.29371250.554625.7804P1104.584552.79551087.557544.28229 141310.622655.81481338.617669.81221321.591661.2990A1007.531504.2691990.5043495.75588 151423.706712.35681451.701726.35431434.675717.8410I936.4938468.7505919.4672460.23737 161494.744747.87541522.738761.87281505.712753.3596A823.4097412.2085806.3832403.69526 171607.828804.41741635.822818.41491618.796809.9016L752.3726376.6899735.3461368.17675 181722.854861.93091750.849875.92831733.823867.4151D639.2885320.1479622.2620311.63464 191885.918943.46251913.913957.46001896.886948.9467Y524.2616262.6344507.2350254.12123 202071.9971036.50222099.9921050.4502082.9661041.986W361.1983181.1028344.1717172.58952 21 R175.119088.0631158.092479.54981 Supplementary Table S3. DvAOX-specific amino acid sequence (DIESGVIQDSPAPAIALDYWR) detected by nano LC–MS/MS. Bold red italic represents the series that contributed to the score. Bold red indicates that the number of matches in the ion series is greater than would be expected by chance, indicating that the ion series is present. Non-bold red shows that the number of matches in the ion series is no greater than would be expected by chance.