18th International Symposium on Iron Nutrition and Interaction in Plants
Madrid – May 30-June 3 2016
DECIPHERING THE ROLE OF LIPID-PROTEIN INTERACTIONS IN CELL FATE
ASSIGNMENT AND FE DEFICIENCY RESPONSE
Jorge E. Salazar-Henao and Wolfgang Schmidt*
Institute of Plant and Microbial Biology, Academia Sinica, 11529 Taipei, Taiwan.
*[email protected]
Iron (Fe) is an essential nutrient for all living organisms. Despite its usually high abundance in soils, Fe is
often not readily available due to its limited solubility in soils with neutral to basic pH. In plants, Fe is required
for basic redox reactions in photosynthesis and respiration and for many vital enzymatic reactions associated
with DNA replication, lipid metabolism and nitrogen fixation. Iron deficiency is the most common plant
nutritional disorder worldwide, affecting a large portion of the world’s population. According to the WHO,
approximately 2 billion people – over 30 % of the world’s population – are anemic, many due to Fe
deficiency. Thus, increasing in the acquisition of Fe by plant is of considerable interest in agriculture and
plant biotechnology.
The adaptation of plants to Fe deficiency evolved as an amalgam of features. Both the length and the
frequency of root hairs are responsive to environmental signals to ensure an optimal acquisition of soil
resources. In particular, mineral nutrients with limited mobility in most soil systems such Fe and phosphate
(Pi), can affect root hair morphogenesis1,2,3.
In this research project, we are attempting to decipher the regulation of the cell fate assignment in the root
epidermis and how Fe and Pi availability affects the morphogenesis of root epidermal cells. Previous studies
showed that the single repeat Myb transcription factor CAPRICE (CPC) promotes differentiation of hairforming cells. The loss the CPC function causes a dramatic reduction in root hair density. Also, the increase
in root hair density and length in response to Pi deficiency is dramatically less pronounced in cpc plants than
in the wild type. CPC is mainly expressed in non-hair cells and migrates to hair cells to promote the root hair
cell fate. The mechanism of this cell-to-cell movement awaits elucidation.
Using a combination of top-down omics approaches and cell biology-based hypothesis-driven experiments,
we attempt to decipher the regulatory cross-talk underlying the control of cell fate and the adaptations to low
Pi availability. The top-down parts comprises the identification of direct targets of CPC by Chromatin
Immuno-Precipitation sequencing (ChIP-seq) and single-cell transcriptional analysis via RNA Sequencing
(RNA-seq) of lines with compromised expression of CPC and enzymes involved in lipid metabolism. The
hypothesis-driven part addresses a possible regulation of cell differentiation by phosphatidylinositol
phosphates (PIPs) and phosphatidic acid (PA)-mediated cell-to-cell movement and nuclear localization of
cell fate-related Myb proteins, respectively. The combination of results obtained will help to understand the
complex interplay of different layers of gene regulation, which control developmental and physiological
processes that acclimate plants to low Fe and Pi availability. As a long-term goal, the results from this project
will benefit the development of strategies to generate cultivars with increased Fe and Pi acquisition
efficiency.
Key words: Cell fate, root development, root hairs, iron deficiency, phosphate deficiency
1. Ma, Z., Bielenberg, D.G., Brown, K.M., Lynch, J.P., (2001). Plant Cell Environ 24, 459-467.
2. Müller, M., Schmidt, W., (2004). Plant Physiol 134, 409-419.
3. Yang, T.J., Perry, P.J., Ciani, S., Pandian, S., Schmidt, W., (2008). J Exp Bot 59, 3453-3464.
Preferred Presentation format: POSTER
Selected Sessions: Molecular regulation of Fe Homeostasis
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