Arabidopsis TCH4, regulated by hormones and the environment, encodes a xyloglucan endotransglycosylase.
Adaptation of plants to environmental conditions requires that sensing of external stimuli be linked to mechanisms of morphogenesis. The Arabidopsis TCH (for touch) genes are rapidly upregulated in expression in response to environmental stimuli, but a connection between this molecular response and developmental alterations has not been established. We identified TCH4 as a xyloglucan endotransglycosylase by sequence similarity and enzyme activity. Xyloglucan endotransglycosylases most likely modify cell walls, a fundamental determinant of plant form. We determined that TCH4 expression is regulated by auxin and brassinosteroids, by environmental stimuli, and during development, by a 1-kb region. Expression was restricted to expanding tissues and organs that undergo cell wall modification. Regulation of genes encoding cell wall-modifying enzymes, such as TCH4, may underlie plant morphogenetic responses to the environment.
Xu
W
W
Department of Biochemistry and Cell Biology, Rice University, Houston, Texas 77251-1892, USA.
Purugganan
M M
MM
Polisensky
D H
DH
Antosiewicz
D M
DM
Fry
S C
SC
Braam
J
J
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics*; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D016695:Glycosyltransferases / Q000235:genetics* / Q000502:physiology; D007210:Indoleacetic Acids / Q000494:pharmacology; D008969:Molecular Sequence Data; D005810:Multigene Family; D010937:Plant Growth Regulators / Q000494:pharmacology; D017386:Sequence Homology, Amino Acid
D017931:DNA Primers; D018744:DNA, Plant; D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; D016695:Glycosyltransferases; C073693:xyloglucan endotransglycosylase