Crosstalk between phosphate transport and plant immunity (Curr. Biol.)

Plants have evolved signaling cascades to survive biotic and abiotic stresses, and recent studies have shown that there is crosstalk between many of these pathways.  In a recent study, Dindas et al. developed a micro-electrode-based system to detect active inorganic phosphate (Pi) transport in Arabidopsis seedlings in real-time. Pi transport can be observed as membrane depolarization when the seedlings are transferred from Pi-deficient media to Pi-containing media. This Pi transport is mediated by PHOSPHATE TRANSPORTER (PHT1;4). The authors observed the lack of this transport if PAMP triggered immunity (PTI) is activated before Pi supplementation. On the other hand, PHT1;4 mediated Pi uptake negatively regulates plant immunity. Two known plant immunity-related kinases BIK1 and PBL1 appear as key intermediates in this Pi transport-immunity crosstalk. When grown in natural soil, mutants of BIK1 or PHT1 show altered root microbiome than their respective wild-type plants. This indicates that Pi transport across the membrane can play a role in determining  structure of microbial community in the roots. Overall this article presents a method for the detection of real-time Pi uptake and identifies key players involved in crosstalk between abiotic and biotic stress tolerance. (Summary and image by Kamal Kumar Malukani, @KamalMalukani) Curr. Biol. 10.1016/j.cub.2021.11.063