During the past decade, molecular genetic studies on the reference plant Arabidopsis have established a largely linear signal transduction pathway for the response to ethylene gas. The biochemical modes of action of many of the signaling components are still unresolved. During the past year, however, progress in several areas has been made on several fronts. The different approaches used have included a functional study of the activity of the receptor His kinase, the determination of the ethylene receptor signaling complex at the endoplasmic reticulum and of the regulation of CONSTITUTIVE TRIPLE RESPONSE1 (CTR1) activity by these receptors, the identification of a unique MITOGEN-ACTIVATED PROTEIN KINASE (MAPK) cascade, the cloning and characterization of numerous ETHYLENE INSENSITIVE3 (EIN3)/EIN3-like (EIL) transcription factors from many plant species, and the integration of the ethylene and jasmonate response pathways via the ETHYLENE RESPONSE FACTOR (ERF) family of transcription factors. The elucidation of the biochemical mechanisms of ethylene signal transduction and the identification of new components in the ethylene response pathway in Arabidopsis are providing a framework for understanding how all plants sense and respond to ethylene.

Cryptochromes and phytochromes are the major photosensory receptors in plants and often regulate similar photomorphogenic responses. The molecular mechanisms underlying functional interactions of cryptochromes and phytochromes remain largely unclear. We h

Cryptochromes are blue/ultraviolet-A light receptors that mediate various light responses in plants and animals1,2. But the initial photochemical reaction of cryptochrome is still unclear. For example, although most photoreceptors are known to undergo lig

Plants use ethylene gas as a signal to regulate myriad transdevelopmental processes and stress responses. The Arabidopsis EIN3 protein is a key transcription factor remediating ethylene-regulated gene expression and hismorphological responses. Here, we re

During the past decade, molecular genetic studies on the reference plant Arabidopsis have established a largely linear signal transduction pathway for the response to ethylene gas. The biochemical modes of action of many of the signaling components are st