| Abstract Detail
Tropisms Shiva Kumar, Neela [1], Spence, Ashley [2], Kiss, John [2]. Plastid Sedimentation and Localization Studies of arg1 Seedlings in Arabidopsis. The response of a plant to gravity is essential for its normal growth and development. Our studies focused on the mechanisms of gravitropism in roots and shoots of Arabidopsis. The ARG1 (altered response to gravity) protein, which has an actin cytoskeleton-binding domain, has been implicated to play a role during signal transduction phase of gravitropism. The arg1 mutants exhibited delayed and reduced gravitropism in roots and shoots. Our results show that ARG1 affects gravitropism in hypocotyls by reducing the plastid sedimentation, a process that is an essential step for further signal cascading events within the statocytes, gravity-perceiving cells. Previous studies on ARG1-GFP genetic line of Arabidopsis in roots using confocal and multiphoton microscopy have indicated that the ARG1 protein appears to be localized to Golgi apparatus, endoplasmic reticulum and vesicles near the plasma membrane. However, the precise location of ARG1 protein within the columella cells needs further investigation by higher resolution electron microscopy. Therefore, we have developed a method for indirect immunogold labeling that is suitable for Arabidopsis roots. Our results confirm that ARG1 is localized to the endomembrane system and that this protein plays a key role in the cellular mechanisms of gravitropism. (Financial Support by NASA grant: NCC2-1200 and DUOS grant from Miami University).
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1 - Miami University, Department of Botany, 316 Pearson Hall, High Street, Oxford, OHIO, 45056, USA
2 - Miami University, Department of Botany
Keywords:
gravitropism
arg1
columella
statocytes
Signal transduction.
Presentation Type: Plant Biology Abstract
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P32006
Abstract ID:1133 |
