植物学及园艺学英文版_botany_and_horticulture_28.ppt

* Molecular mechanisms of ethylene signaling in Arabidopsis Larissa M. Benavente and Jose M. Alonso* Received 30th September 2005, Accepted 16th December 2005 First published as an Advance Article on the web 19th January 2006 DOI: 10.1039/b513874d Abstract Ethylene is a gaseous plant hormone involved in several important physiological processes throughout a plant’s life cycle. Decades of scientific research devoted to deciphering how plants are able to sense and respond to this key molecule have culminated in the establishment of one of the best characterized signal transduction pathways in plants. The ethylene signaling pathway starts with the perception of this gaseous hormone by a family of membrane-anchored receptors followed by a Raf-like kinase CTR1 that is physically associated with the receptors and actively inhibits downstream components of the pathway. A major gap is represented by the mysterious plant protein EIN2 that genetically works downstream of CTR1 and upstream of the key transcription factor EIN3. Transcriptional regulation by EIN3 and EIN3-family members has emerged as a key aspect of ethylene responses. The major components of this transcriptional cascade have been characterized and the involvement of post-transcriptional control by ubiquitination has been determined. Nevertheless, many aspects of this pathway still remain unknown. Recent genomic studies aiming to provide a more comprehensive view of modulation of gene expression have further emphasized the ample role of ethylene in a myriad of cellular processes and particularly in its crosstalk with other important plant hormones. This review aims to serve as a guide to the main scientific discoveries that have shaped the field of ethylene biology in the recent years EFFECTS OF ETHYLENE Fruit Ripening Abscission; leaf flower fruits (thinning, harvesting) Hook Closure Maintenance Initiates Germination in Grains Activates dormant buds (potatoes in storage) Stem elongation in deep-water rice