The signal intensity of system-2 ethylene mediates the efficiency of the tomato ripening machinery. A, Statistics of days from anthesis to the color breaker stage in fruits of the WT and corresponding mutant alleles. Error bars indicate sd. Different letters above the bars indicate statistically significant differences between the samples (n = 20, P < 0.01, Student’s t test). B, Relative mRNA levels of ripening-associated ethylene signaling marker genes E4 and E8 in WT, sleil1, sleil1 sleil4, sleil1 sleil3 sleil4, and slein2-1 fruits at the Br + 10 stage. Error bars indicate sd. Different letters above the bars indicate statistically significant differences between the samples (n = 3, P < 0.01). C, Statistics of days from the color breaker to red ripening stage in WT, sleil1, sleil1 sleil4, sleil1 sleil3 sleil4, and slein2-1 fruits. Error bars indicate sd. Different letters above the bars indicate statistically significant differences between the samples (n = 20, P < 0.01, Student’s t test). n.d., no data available. D, Ethylene production of WT, sleil1, sleil1 sleil4, and sleil1 sleil3 sleil4 fruits at different ripening stages. Error bars indicate sd (n = 12). E and F, Relative mRNA levels of SlACS2 (E) and RIN (F) of WT, sleil1, sleil1 sleil4, and sleil1 sleil3 sleil4 fruits at different ripening stages. Error bars indicate sd. Different letters above the bars indicate statistically significant differences between the samples (n = 3, P < 0.01, Student’s t test). G, Br + 10 fruits that were harvested from WT, sleil1, sleil1 sleil4, sleil1 sleil3 sleil4, and slein2-1 plants and stored at room temperature for two months. H, Physiological loss of water (weight loss %) in WT, sleil1, sleil1 sleil4, sleil1 sleil3 sleil4, and slein2-1 fruits during different stages of storage. The weight loss per fruit was calculated at 10, 20, 30, and 60 days after storage. Error bars indicate sd. Different letters above the bars indicate statistically significant differences between the samples (n = 20, P < 0.01, Student’s t test).