to Selection and ordering data Dimensions in mm B3-DH7-B Bevel-helical gear boxes B3

Flender/Flender Gear Units/Bevel-helical gear boxes B3

rane-bound protein that binds ethylene, whereas CTR1 encodes protein that blocks the activity of EIN2 and subsequent downstream signal transduction.When present, ethylene may bind to and activate the ETR1 protein. The concentration ofethylene necessary to activate the ETR1 protein is quite low. In transgenic yeast containingthe ETR1 gene, the (dissociation constant) of ETR1 is 0.0 LL/H1ethylene (gas phase) (, which is close to the amount of ethylene required for half-maximal response inthe seedling growth assay. Binding of ethylene to ETR1 is reversible. The release of bound ethylene from the transgenic yeast has half-life of 1 , rate similar to that observed with one class of binding activity reported from several plant sources (. The ethylene Fig. 6 Proposed linear sequence of gene action in the ethylene transduction pathway of Arabi- dopsis thaliana (.) Heynh. In the absence of ethylene, CTR1 inactivates EIN2. In the presence of ethylene, an ethyleneETR1 complex is formed that inactivates CTR1. Once CTR1 is inactive, the EIN2 gene is free to activate the rest of the sequence. (Adapted from Refs. 1, 1, and 1.) 4 DeEll et al. ETR1 complex may then inactivate CTR1, either directly or indirectly (through an interac- tion with EIN and possibly through phosphorylation. With CTR1 inactivated, the EIN2gene may then activate ethylene-regulated genes, possibly by acting on genes like EIN3(or EIN and those producing EREBPs. More research in the future will verify the validityof this proposed sequence and how universal it may be in plants other than . thaliana . 4.3 Inhibitors of Ethylene Production or Action 4.3.1 Ethylene ProductionThere are numerous inhibitors that endogenously or exogenously inhibit ethylene produc- tion (. Many of these inhibitors vary in their capacity to inhibit ethylene production and occasionally may stimulate ethylene production (.., CO . The following are some of the best known and consistent inhibitors. ACC synthase is inhibited