18th International Symposium on Iron Nutrition and Interaction in Plants
Madrid – May 30-June 3 2016
TITLE: TRANSCRIPTOMIC ANALYSES REVEAL NOVEL FIT TARGETS, TEMPORALLY FIT-DEPENDENT
GENES AND FUNCTIONALLY DISTINCT ROBUSTLY IRON DEFICIENCY-INDUCED REGULONS.
Hans-Jörg Mai and Petra Bauer*
Heinrich Heine University, Universitätsstraße 1, Building 26.13 Room 02.26, 40225 Düsseldorf, Germany
*[email protected]
ABSTRACT: FIT (FER-LIKE IRON DEFICIENCY-INDUCED TRANSCRIPTION FACTOR) is the central
regulator of iron uptake in Arabidopsis thaliana [1-3]. Transcriptomic and co-expression analysis revealed a
number of FIT targets [2] and a regulon of FIT-dependent genes [4]. To extend the analytic strategy we
performed CATMA microarray analyses of six day-old seedlings and roots of six week-old A. thaliana plants
using wild-type, a fit knock-out mutant and a FIT over-expression line grown under iron-sufficient or irondeficient conditions. By stringent filtering of the regulated genes by their expression patterns we detected 32
stably FIT-regulated genes including 11 novel FIT targets. 64 genes were regulated in a FIT-dependent
manner only in seedlings while 267 genes were regulated in a FIT-dependent manner only in roots of sixweek-old plants. Out of these 331 temporally FIT-dependent genes 307 are novel FIT targets. Additionally, we
assembled a virtual dataset of iron-regulated genes using our own and 12 transcriptomic analyses from 9
previous publications [2, 4-11] to pinpoint the most stably iron deficiency-regulated genes. Co-expression
analysis of the genes in this dataset revealed 13 distinct regulons most of which predominantly contained
functionally related genes. Hence, besides the detection of novel FIT target genes we could show that a large
subset of these genes can temporally fall into or out of the control of FIT depending on the plant’s age or
developmental stage. With the virtual dataset we could filter the regulatory noise and pinpoint new candidates
among the most reliable marker genes for iron deficiency. Moreover, co-expression and functional analysis of
the virtual dataset revealed multiple functionally distinct iron deficiency-induced regulons.
Keywords: Iron deficiency Arabidopsis FIT co-expression
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Preferred Presentation format: POSTER or TALK
Selected Sessions: Molecular regulation of Fe homeostasis
1