ACC/Ethylene pretreatment or enhanced ethylene signaling increases salt tolerance.

<p>(A) Plants were grown on MS medium with or without 10 µM ACC for 5 d and then transferred onto MS medium supplemented with 200 mM NaCl for 3 d. Plants were also transferred onto MS medium as controls. (B) Survival rate of plants shown in (A). Seedling death was scored as complete bleaching of cotyledons and leaves. Values are mean ± SD from 25 seedlings per replicate (<i>n</i> = 3 replicates). (Student's <i>t</i> test, *P<0.05 and **P<0.01). (C) Relative electrolyte leakage of plants shown in (A). Values are mean ± SD from 50 seedlings per replicate (<i>n</i> = 3 replicates). (Student's <i>t</i> test, *P<0.05 and **P<0.01). (D) Survival rate of plants pretreated with air (Air) or 20 ppm ethylene (ET) for 5 d and then transferred onto MS medium supplemented with 200 mM NaCl. Survival rates were calculated on the second, third and fourth day. Values are mean ± SD from 20 seedlings per replicate (<i>n</i> = 4 replicates). (Student's <i>t</i> test, *P<0.05 and **P<0.01). (E) Survival rate of plants pretreated with air or 20 ppm ethylene for indicated time and then transferred onto medium supplemented with 200 mM NaCl. Survival rates were calculated on the third day after transfer. Values are mean ± SD from 20 seedlings per replicate (<i>n</i> = 4 replicates). A5E0: 5 d of air treatment. A2E1A2: 2 d of air followed by 1 d of ethylene then 2 d of air treatment. A1E2A2: 1 d of air followed by 2 d of ethylene then 2 d of air treatment. A0E5: 5 d of ethylene treatment. ET: ethylene. (Student's <i>t</i> test, *P<0.05 and **P<0.01).