Cytoskeleton Structure and Dynamics
Weizbauer, Renate A , Schulz, Burkhard .
What puts a twist in twisted dwarf1? – a cytological approach.
The mutation in TWISTED DWARF1 (TWD)1, which in its wild type form seems to
fulfill the function of a regulator protein in the inter- and intracellular auxin transport, results in a very interesting phenotype. Root and shoot exhibit a decrease in growth due to reduced cell elongation, as well as a twisting of all organs, the so called ‘macro-twist’, and within the epidermal cell files of roots and shoots, the ‘micro-twist’.
The immunophilin TWD1 belongs to the FK506 binding protein family (FKBP) and is its only member with a membrane anchor. It also consists of an FKBP-like domain, a tripartite TPR motif and a CaM binding site. TWD1 was shown to interact with ABC transporters involved in auxin transport, e.g. AtPGP1 and AtPGP19 in the PM via the FKBP-like domain, and with AtMRP1 and AtMRP2 in the tonoplast through the TPR domain.
The helical twisted epidermial cell files in the twd1 mutant suggest a change in orientation of the cortical microtubules (CMT) which are usually aligned perpendicular to the direction of elongation. Similar helical cell twists in the epidermis have been observed in mutants with changes in CMT stability or dynamics, e.g. spiral1, tor1, lefty1 and lefty2. In order to determine changes in the cytoskeleton, markers have been introduced into the twd1 background and these changes will be observed via confocal microscopy. Differences in the cell wall composition and cellulose alignment can also cause irregular cell and organ shape. An experimental approach to investigate differences in cell walls of twd1 and wild-type plants will be presented.
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1 - Purdue University, Horticulture and Landscape Architecture, 625 Agriculture Mall Dr., West Lafayette, IN, 47907, USA
2 - Purdue University, Horticulture and Landscape Architecture
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM