Arabidopsis root hair development in adaptation to iron and phosphate supply [Elektronische Ressource] / von Margarete Müller

Arabidopsis root hair development in adaptation to iron and phosphate supply D i s s e r t a t i o n zur Erlangung des akademischen Grades d o c t o r r e r u m n a t u r a l i u m (Dr. rer. nat.) im Fach Biologie eingereicht an der Mathematisch-Naturwissenschaftlichen Fakultät I der Humboldt-Universität zu Berlin von Diplom-Biologin Margarete Müller geboren am 13.7.1973 in Leer Präsident der Humboldt-Universität zu Berlin Prof. Dr. Christoph Markschies Dekan der Mathematisch-Naturwissenschaftlichen Fakultät I Prof. Dr. Christian Limberg Gutachter: Prof. Dr. Thomas J. Buckhout PD Dr. Wolfgang Schmidt Tag der mündlichen Prüfung: 27. 02. 2007 ABSTRACT Limitation of immobile nutrients, such as iron (Fe) and phosphate (P), induces the development of additional root hairs that lead to an increase of the absorptive surface of the root. The increased root hair frequency of Fe- and P-deficient Arabidopsis was realized by different strategies. Phosphate-deficient plants increased the number of root hairs while in Fe-starved plants root hairs were branched. The Fe and P starvation responses in plants are thought to be regulated by a systemic signaling mechanism that communicates the nutrient status of the shoot to the root and by a local signaling mechanism that perceives the Fe or P availability in the soil. The influence of local and systemic signals on the respective root hair phenotype was investigated in split-root experiments.