Silicon mitigates potassium deficiency by enhanced remobilization and modulated potassium transporter regulation
Year: 2022
Type: article
Abstract: Silicon (Si) improves plant growth and development especially under stress conditions. Although Si alleviates growth suppression and deficiency symptoms of several nutrient disorders, underlying regulatory processes have remained indefinite. Here, we analyzed the impact of Si on nutritional, metabolic and transcriptional responses in roots and shoots of barley subjected to potassium (K) deficiency. On the long run, Si nutrition improved root and shoot growth as well as metabolite homeostasis and partly reverted the K deficiency signature of the transcriptome back to adequate only in fully expanded leaves but hardly in roots. In the short term, Si supply to K-starved roots enhanced first the expression of the vacuolar K exporter KCO1 together with root-to-shoot translocation rates of rubidium (Rb) that was used as tracer for K. The typical K deficiency response, marked by upregulation of the K importer genes HAK1 and AKT1, set in a few days later but then at several-fold higher levels. Lower root K and higher shoot K contents in Si-supplied plants indicated more efficient remobilization of root K pools and higher root-to-shoot translocation, which on the long run restored K-dependent metabolic processes in shoots for the sake of continued assimilate provision to roots. These results provide a sequence of physiological processes by which Si partially recovers plants from K deficiency and indicate that Si interferes with systemic K deficiency signaling in roots to alter the regulation of K transporters.
Authors: Sara Beier, Nara C. Marella, Jean-Claude Yvin, Seyed Abdollah Hosseini, Nicolaus von Wirén
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: hybrid
Estimated APC paid: $3,550
Funder: Leibniz-Gemeinschaft
OpenAlex ID: W4220780932