The ethylene signal transduction pathway is well understood

Analysis of Arabidopsis mutants has revealed the steps in the mechanism of ethylene action. Some of these mutants do not respond to applied ethylene, and others act as if they have been exposed to ethylene even though they have not. Studies of the mutant genes and their protein products, coupled with comparisons of their amino acid sequences with those of other known proteins, have revealed some of the details of the signal transduction pathway through which ethylene produces its effects (Figure 38.17). The pathway includes two membrane proteins: The first is an ethylene receptor (ETR1), and the second is a channel (EIN2) that acts through a second messenger to activate a transcription factor (EIN3). The transcription factor turns on the genes that produce ethylene's effects in the cell. Ethylene was the first plant hormone to have its mechanism of action elucidated in this way.

(a) Ethylene absent (b) Ethylene present

(a) Ethylene absent (b) Ethylene present

Ethylene Signal Transduction Pathway
.. .which turns on the expression of genes whose products lead to the physiological effects of ethylene.

38.17 The Signal Transduction Pathway for Ethylene This slightly simplified diagram shows the roles of four proteins (ETR1, CTR1, EIN2, and EIN3) in the signal transduction pathway through which ethyl-ene exerts its effects.

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  • kristian
    Is ethylene a plant hormone?
    8 years ago

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