Biology

Dr. Santosh Sathbhai
Gregor Mendel Institute of Molecular Plant Biology, Vienna, Austria

Iron (Fe) is an important mineral micronutrient for plants and animals. Low availability of Fe significantly limits crop yield in many parts of the world and has consequently has serious impacts on human nutrition. In fact, Fe availability is one of the major limitations for plant growth because Fe forms insoluble ferric oxides in soil. Due to limited bioavailability of Fe, plants have evolved into sophisticated adaptive alterations in their developmental program. In particular, modifications of root architecture that are caused by the adjustment of root growth traits are a key for the survival of plants on Fe-deficient soils. Understanding the genetic and molecular bases for these root growth responses would not only answer fundamental biological questions, but also have important implications for plant breeding or engineering. To understand the genetic bases of root growth responses to Fe deficiency, we have studied the early root development using the model plant Arabidopsis thaliana (Arabidopsis) natural accessions under Fe-deficient condition. We used a diverse set of 450 natural accessions of Arabidopsis to identify genes that quantitatively regulate root growth responses to Fe deficiency using genome wide association mapping. Strikingly, these plants showed high variation in their primary root elongation when grown on Fe-deficient medium. We identified several statistically significant genomic loci that are associated with changes in root growth rate upon Fe deficiency. The identification of novel regulators and their alleles that are coordinating growth responses to iron deficiency conditions using GWAS demonstrates the power of our approach and promises to aid in the generation of crops with improved nutritional quality and increased growth in Fe-deficient soils.