Combating plant diseases through transition metal allocation

This viewpoint explores the various strategies that plants employ to defend against pathogenic microorganisms using metals. Iron, copper, zinc, and other transition metals are essential nutrients for plants at low concentrations as these elements are essential for the correct function of many proteins. However, at slightly higher levels, transition metals become toxic. Considering this, plants employ different strategies to defend against pathogens using metals (Figure 1). One approach involves limiting the pathogens' access to metals (nutritional immunity), while another uses high concentrations that can be toxic to the pathogens (elemental or direct defence). Therefore, it is essential to assess the impact of the nutritional status of agriculturally relevant species on their defensive responses to major threats. Data generated by the research team and included in the review were supported by grant TED2021-131769B- 100 funded by MCIN/AEI/10.13039/501100011033 and by the European Union Next Generation EU/PRTR, and the Severo Ochoa Program for Centres of Excellence in R&D from the Agencia Estatal de Investigación of Spain (CEX2020- 000999S) awarded to CBGP (UPM-INIA/CSIC).