BIG link between light signaling and auxin transport
Researchers from the Salk Institute have discovered an enormous link between light and auxin signal transduction pathways 560 kiloDaltons, to be exact.
It was first noticed in the late1920s that changes in levels of the plant hormone, auxin, occur during light-regulated growth responses (ie., the phototrophic response, or the tendency of plants to grow towards the source of light). Until recently, though, genetic evidence linking plants response pathways to light and auxin has been lacking.
Dr. Joanne Chory and colleagues discovered that two previously identified Arabidopsis muatnts doc1, which displays abnormal expression of light-regulated genes, and tir3, known for its resistance to inhibitors of auxin transport are actually two alleles of the same gene. This gene encodes a 560kD protein, which they aptly named "BIG." This work is of interest not only because BIG effectively bridges the gap between auxin- and light-mediated responses, but also due to the similarity that BIG displays to the Calossin gene family found in worm, flies and humans.
Putting out the fire: a role for IP3 in plant cell signaling
Researchers at the University of Arizona have made a significant advance in understanding how plants respond to stress.
The plant hormone abscisic acid (ABA) coordinates plant developmental programs with specific environmental stress responses by activating the expression of stress-adaption genes. Dr. Jian-Kang Zhu and colleagues have discovered that the molecule IP3 (inositol 1, 4, 5-triphosphat
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Contact: Nora Poppito
poppito@cshl.org
Cold Spring Harbor Laboratory
31-Jul-2001