Elsbeth Walker

Education: 

A.B., Mount Holyoke College, 1984
Ph.D., Rockefeller University, 1990

Postdoctoral: 

1990-1993 Yale University

Research Interests: 

Plant Genetics and Physiology

Iron Homeostasis in Plants

Iron Homeostasis in Plants

Iron is one of the most important and most problematic of all the micronutrients used by living organisms. Iron is an essential cofactor for many cellular redox reactions, yet the same high reactivity that makes it so useful can cause cellular damage if iron is not carefully controlled. Add to this problem that iron is also only sparingly soluble in aqueous solution, and it is easy to see why plants have evolved multifaceted iron homeostatic mechanisms. These mechanisms include control of uptake, translocation from organ to organ and cell to cell, re-mobilization of stored iron, as well as poorly understood sensing and signaling systems by which the plant communicates its iron status between tissues. Many of the mechanisms involved in plant iron homeostasis are not well understood, and this is a major obstacle to devising approaches for biofortification of staple foods with iron. Biofortification refers to the genetic engineering of staple crops to accumulate additional bioavailable iron in edible parts; it is widely regarded as a sustainable means of improving the iron nutrition of the 2-3 billion people worldwide whose inadequate diet causes iron deficiency anemia.

My group has a strong interest in the processes by which plants move iron and other transition metals within their above ground parts. We have worked extensively on members of the Yellow Stripe Like (YSL) family of transporters, which  are required for normal metal loading into both vegetative and reproductive tissues. Currently, we are using a combination of molecular genetic, physiological and “‘omics” approaches to understand how whole plant signaling of iron status occurs.

Representative Publications: 

Bakirbas, A., Castro-Rodriguez, R., and E. L. Walker (2023) The small RNA component of Arabidopsis phloem sap and its response to iron deficiency. Plants 12(15), 2782. https://doi.org/10.3390/plants12152782.

Chia, J-C., Yan, J., Ishka, M.R., Faulkner, M., Simons, E., Huang, R.,  Smieska, L., Woll, A., Tappero, R., Kiss, A., Chen, J., Fei, Z., Kochian, L., Walker, E.L., Piñeros, M., and O.  Vatamaniuk (2023). Loss of OPT3 function decreases phloem copper levels and impairs crosstalk between copper and iron homeostasis and shoot-to-root signaling in Arabidopsis thaliana The Plant Cell  https://doi.org/10.1093/plcell/koad053.

Bakirbas, A. and E. L. Walker (2022) CAN OF SPINACH, a novel long non-coding RNA, affects iron deficiency responses in Arabidopsis thaliana. Frontiers in Plant Science 13:1005020. https://doi.org/10.3389/fpls.2022.1005020.

Castro-Rodríguez, R. Reguera, M, Escudero,V., Gil-Díez, P. Quintana, J., Prieto, R.I., Kumar,  R.K., Brear, E., Grillet, L., Wen, J., Mysore, K.S., Walker, E. L., Smith, P.M.C., Imperial, J., González-Guerrero, M. (2021) Medicago truncatula Yellow Stripe-Like7 encodes a peptide transporter required for symbiotic nitrogen fixation. Plant Cell & Environment https://doi.org/10.1111/pce.14059.

Chan Rodriguez, D. and E. L. Walker (2018) Analysis of yellow striped mutants of Zea mays reveals novel loci contributing to iron deficiency chlorosis. Frontiers in Plant Science 9:157. https://doi.org/10.3389/fpls.2018.00157.

Kumar, R. K., Chu, H-H., Abundis, C. A., Vasques, K., Chan-Rodriguez, D., Chia, J-C, Huang, R., Vatamaniuk, O. K., and E. L. Walker (2017)  The Iron-Nicotianamine Transporters, Yellow Stripe1-Like1 and 3 Regulate Long Distance Shoot to Root Signaling of Iron Deficiency in Arabidopsis. Plant Physiology 175:1254. https://doi.org/10.1104/pp.17.00821.