RT Journal Article
SR Electronic
T1 A Common Position-Dependent Mechanism Controls Cell-Type Patterning and <em>GLABRA2</em> Regulation in the Root and Hypocotyl Epidermis of Arabidopsis
JF Plant Physiology
JO Plant Physiol.
FD American Society of Plant Biologists
SP 73
OP 84
DO 10.1104/pp.117.1.73
VO 117
IS 1
A1 Hung, Chen-Yi
A1 Lin, Yan
A1 Zhang, Meng
A1 Pollock, Susan
A1 David Marks, M.
A1 Schiefelbein, John
YR 1998
UL http://www.plantphysiol.org/content/117/1/73.abstract
AB A position-dependent pattern of epidermal cell types is produced during root development inArabidopsis thaliana. This pattern is reflected in the expression pattern of GLABRA2 (GL2), a homeobox gene that regulates cell differentiation in the root epidermis. GL2 promoter::GUSfusions were used to show that the TTG gene, a regulator of root epidermis development, is necessary for maximalGL2 activity but is not required for the pattern ofGL2 expression. Furthermore, GL2-promoter activity is influenced by expression of the myc-like maize R gene (35S::R) in Arabidopsis but is not affected by gl2 mutations. A position-dependent pattern of cell differentiation andGL2-promoter activity was also discovered in the hypocotyl epidermis that was analogous to the pattern in the root. Non-GL2-expressing cell files in the hypocotyl epidermis located outside anticlinal cortical cell walls exhibit reduced cell length and form stomata. Like the root, the hypocotylGL2 activity was shown to be influenced byttg and 35S::R but not bygl2. The parallel pattern of cell differentiation in the root and hypocotyl indicates that TTG andGL2 participate in a common position-dependent mechanism to control cell-type patterning throughout the apical-basal axis of the Arabidopsis seedling. bHLHbasic helix-loop-helix4-MUG4methylumbelliferyl β-d-glucuronic acidX-Gluc5-bromo-4-chloro-3-indolyl-β-d-glucuronic acid