Different endogenous volatiles and other factors that play regulatory role in determining the production as well as the response of ethylene. The symbols , , >, < and indicate inducers, suppressors, higher, lower and possible interaction respectively. SAM: S-Adenosyl-L-methionine, ACC: 1-Amino-cyclopropane-1-carboxylic acid, SA: Salicylic acid, MSA: Methyl salicylic acid, JAs: Jasmonates, NO: Nitric oxide