The 30th International Conference on Arabidopsis Research (ICAR 2019)

481 / 2019-02-28 01:08:49

Identification of gene regulatory networks mediating the early responses to iron deficiency in leaves.

Iron homeostasis, GNRs, Iron sensing

Plenary track > Nutrition

Iron (Fe) is an essential nutrient for plants and humans and plants are the main dietary source of Fe for humans. Therefore, understanding the mechanisms by which plants sense and allocate Fe to edible tissues will help developing more nutritious food. Despite advances over the last decade at identifying molecular players of the Fe deficiency response, the sensing and the precise location of Fe sensing within the plant remains under investigation. We recently took advantage of tissue-specific Fe deficiency markers to determine the timing and location of early transcriptional responses during Fe limitation. Our results show that the leaf vasculature is within the first tissues that sense and respond to changes in Fe availability, hours before the well-established Fe deficiency response in roots. Additional data also suggest that source leaves and sink leaves also respond differently to Fe deficiency. To expand on these findings, we conducted a RNA-seq time-series analysis of source Arabidopsis leaves within the first 15 hrs of plants experiencing Fe limitation. Gene regulatory network analyses allowed us to identify discrete sub networks that we hypothesize mediate the adaptation of leaf development when Fe becomes limiting. At the ICAR 2019 meeting we will present an integrated model of Fe deficiency responses emphasizing the importance of the leaf vasculature as a key component of the Fe sensing mechanisms critical to maintain iron homeostasis in plants.