A research team has identified a novel Fe-binding domain allele called BTS in a mutagenesis screen for altered Fe accumulation (bts-3). Data showed that bts-3 is more tolerant than wild type to Fe-deficient conditions and that bts-3 is sensitive to Fe-sufficient conditions and accumulates excessive Fe. A triple mutant with loss of both BTS paralogs and a partial loss of BTS expression exhibits even greater tolerance to Fe-deficient conditions and increased Fe accumulation without any resulting Fe toxicity effects, with the mutations also changing their uptake of important minerals such as zinc (Zn) and manganese (Mn). Genetic knockdowns and modifications of the proteins have been implicated in regulating plant uptake of Fe. This work will lead to greater understanding of plant Fe homeostasis to inform efforts for improved crops. Identifying natural variants of these genes in crop species may lead to traditional breeding efforts to generate higher-Fe cultivars.
Hindt, M. N., et al. “BRUTUS and its Paralogs, BTS LIKE1 and BTS LIKE2, Encode Important Negative Regulators of the Iron Deficiency Response in Arabidopsis thaliana.” Metallomics 9(7), 876–890 (2017). [DOI:10.1039/C7MT00152E].
Instruments and Facilities Used: PerkinElmer LAS Ltd, Seer Green, United Kingdom, and Elemental Scientific Inc., Omaha, Neb.; synchrotron X-ray fluorescence (SXRF) at National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory; Stanford Synchrotron Lightsource (SSLS) at SLAC National Accelerator Laboratory (SLAC); real-time quantitative PCR (Step One Plus Real Time PCR System using Applied Biosystems Version 2.2.3; Advanced Photon Source (APS) at Argonne National Laboratory (ANL); and Australian Synchrotron, Victoria. Two-dimensional SXRF analysis was performed at various X-ray microprobe beamlines: microarray analysis and X-ray fluorescence imaging (XFI) on SSLS beamline 2-3 at SLAC; X26A and X27A of NSLS; XFM beamline of the Australian Synchrotron; APS beamline 2-ID-D. Microarray analysis performed at Geisel School of Medicine in the Genomics Shared Resource at Dartmouth College. Elemental concentration analysis (inductively coupled plasma-mass spectrometry (ICP-MS, PerkinElmer NexION 300D equipped with Elemental Scientific Inc. autosampler and Apex HF sample introduction system at PerkinElmer LAS Ltd, Seer Green, U.K., and Elemental Scientific Inc., Omaha, Neb., respectively, in the standard mode.