In the following schematic diagrams of ethylene signaling in plants, 1 denotes ethylene, 2 denotes ethylene receptor, 3 denotes CTR1, 4 denotes EIN3, and 5 represents the expression of ethylene-responsive genes. Which diagram better depicts the signaling pathway? Activation and inhibition are indicated as normal and blunt arrows, respectively.

Question

Quizplus · Accepted Answer

In the ethylene signaling pathway in plant cells, ethylene receptor and CTR1 are active in the absence of ethylene. Active CTR1 stimulates the degradation of of EIN3, preventing it from activating the transcription of ethylene-responsive genes. Ethylene binding inactivates the receptors, resulting in EIN3 accumulation and gene expression.

In the Following Schematic Diagrams of Ethylene Signaling in Plants