2022 journal article

Mycorrhiza-mediated potassium transport in Medicago truncatula can be evaluated by using rubidium as a proxy


By: A. Kafle n, D. Cooney n, G. Shah n & K. Garcia n 

co-author countries: United States of America πŸ‡ΊπŸ‡Έ
author keywords: Arbuscular mycorrhizal symbiosis; Medicago truncatula; Plant nutrition; Potassium; Rhizophagus irregularis; Rubidium
MeSH headings : Medicago truncatula / metabolism; Mycorrhizae / physiology; Plant Roots / metabolism; Potassium / metabolism; Rubidium / metabolism; Symbiosis / physiology
Source: Web Of Science
Added: August 8, 2022

Arbuscular mycorrhizal (AM) fungi considerably improve plant nutrient acquisition, particularly phosphorus and nitrogen. Despite the physiological importance of potassium (K+) in plants, there is increasing interest in the mycorrhizal contribution to plant K+ nutrition. Yet, methods to track K+ transport are often costly and limiting evaluation opportunities. Rubidium (Rb+) is known to be transported through same pathways as K+. As such our research efforts attempt to evaluate if Rb+ could serve as a viable proxy for evaluating K+ transport in AM symbiosis. Therefore, we examined the transport of K+ in Medicago truncatula colonized by the AM fungus Rhizophagus irregularis isolate 09 having access to various concentrations of Rb+ in custom-made two-compartment systems. Plant biomass, fungal root colonization, and shoot nutrient concentrations were recorded under sufficient and limited K+ regimes. We report that AM plants displayed higher shoot Rb+ and K+ concentrations and a greater K+:Na+ ratio relative to non-colonized plants in both sufficient and limited K+ conditions. Consequently, our results indicate that Rb+ can be used as a proxy to assess the movement of K+ in AM symbiosis, and suggest the existence of a mycorrhizal uptake pathway for K+ nutrition in M. truncatula.