Ethylene Signaling in Plants

The gaseous plant hormone ethylene involves various aspects of growth, development, and responses to changing environment, via networking with other hormones, throughout the life cycle of a plant. The ethylene gas functioned as an ancient plant hormone for over 450 million years of evolution in the common ancestor of zygnematophytes, and the signal transduction pathway is highly conserved among plant species. The underlying molecular events of ethylene signaling have been well explained by studies over the past three decades, and there are also questions beyond our knowledge to be resolved. As truth in science is changing over time and biological experiments only fickly reveal part of the truth, our present understanding about ethylene signaling may be innovated by new findings and ideas refreshed from previous studies.