Funktion des SHORT SUSPENSOR Gens, einer cytoplasmatischen Proteinkinase der Pelle/Receptor-like Familie, in der Embryonalentwicklung von Arabidopsis thaliana
Zusammenfassung der Projektergebnisse
In the plant Arabidopsis embryogenesis starts with elongation and asymmetric division of the fertilized egg cell, the zygote. The two daughter cells of the zygote establish lineages with fundamentally different fates. The cells of the apical lineage form the spherical pro-embryo, while the cells of the basal lineage form a mostly extra-embryonic file of cells, termed suspensor. The suspensor is a support structure that positions the embryo within the seed and is implicated in nutrient and hormone transport. The cell fate decision between embryonic and suspensor development of the first two daughter cells is regulated by a MAP kinase signaling pathway. In this project we investigated the role of the cytoplasmic kinase SHORT SUSPENSOR (SSP) in this developmental process. In genetic studies of double mutant combination we could demonstrate that SSP acts in the same MAP kinase pathway as YODA (YDA), a previously characterized member of the MAP cascade. Surprisingly the SSP gene is not active in the embryo where it is functioning but is transcribed in pollen. As a consequence the ssp mutation displays a rare paternal effect where only the paternal allele of SSP is determining the development of the embryo. Even more intriguingly the SSP protein is not produced in pollen but only after fertilization when the pollen delivers the SSP transcript to the developing embryo. The further analysis of the SSP protein revealed that SSP likely functions as an adapter or scaffolding protein rather than a kinase. When we introduce the SSP artificially in leaf epidermis cells, where it normally is not present, it is able to activate the YDA MAP kinase pathway in a process unrelated to embryogenesis. We therefore proposed a model in which SSP is the actual signaling molecule that activates YDA and therefore couples the fertilization event with development of the embryo.
Projektbezogene Publikationen (Auswahl)
-
“SHORT SUSPENSOR, a putative receptor-like cytoplasmic kinase regulating extra-embryonic development of Arabidopsis suspensor cells” 16th International Conference on Arabidopsis Research, June 14-19, 2005; Madison, Wisconsin, USA
Bayer, M. and Lukowitz, L.
-
“The receptor-like cytoplasmic kinase gene SHORT SUSPENSOR regulates extraembryonic development in Arabidopsis”. Plant Genetics 2005 Conference, Mechanisms of Genetic Variation, October 12–16, 2005; Snowbird, Utah, USA
Bayer, M., Alabaster, S., Wetmore, K., Williams, J., and Lukowitz, W.
-
“The Receptor-like Cytoplasmic Kinase Gene SHORT SUSPENSOR Regulates Extra-Embryonic Development in Arabidopsis” 17th International Conference on Arabidopsis Research, June 28th - July 2nd, 2006; Madison, Wisconsin, USA
Bayer, M., Alabaster, S., Wetmore, K., Williams, J., and Lukowitz, W.
-
“The receptor-like cytoplasmic kinase gene SHORT SUSPENSOR regulates extra-embryonic development in Arabidopsis” New York Area Plant Molecular Biology Meeting, 16 May, 2006; The New York Botanical Garden, NY, USA
Bayer, M., Alabaster, S., Wetmore, K., Williams, J., and Lukowitz, W.
-
“The receptor-like cytoplasmic kinase gene SHORT SUSPENSOR regulates extra-embryonic development in Arabidopsis” Northeast Regional Meeting, Society for Developmental Biology, April 28 – 30, 2006; Marine Biological Laboratory, Woods Hole, MA, USA
Bayer, M., Alabaster, S., Wetmore, K., Williams, J., and Lukowitz, W.
-
„The receptor-like cytoplasmic kinase gene SHORT SUSPENSOR regulates extra-embryonic development in Arabidopsis” 2006 FASEB Summer Research Conference: “Mechanisms in Plant Development”, August 5 - 9th, 2006; Vermont Academy, Saxtons River, Vermont
Bayer, M., Alabaster, S., Wetmore, K., Williams, J., Lukowitz, W.
-
(2007): „Talk global, act local – patterning the Arabidopsis embryo”, Current Opinion in Plant Biology
Nawy, T., Lukowitz, W., Bayer, M.
-
“Paternal control of embryonic patterning in Arabidopsis thaliana” New York Area Plant Molecular Biology Meeting, June 2, 2007; Yale University, New Haven CT, USA
Bayer, M., Nawy, T., Alabaster, S., Galli, M., and Lukowitz, W.
-
“Paternal control of embryonic patterning in Arabidopsis thaliana”. Northeast Regional Meeting, Society for Developmental Biology, April 27-29, 2007; Marine Biological Laboratory, Woods Hole, MA, USA
Bayer, M., Nawy, T., Alabaster, S., Galli, M., Williams, J., and Lukowitz, W.
-
„Die pollenspezifische Rezeptorkinase SHORT SUSPENSOR reguliert extraembryonale Entwicklung in Arabidopsis“ 20. Tagung "Molekularbiologie der Pflanzen", February 27th – March 3rd, 2007; Dabringhausen, Germany
Bayer, M., Nawy, T., Alabaster, S., Galli, M., and Lukowitz, W.
