Paxillus involutus-Facilitated Cd2+ Influx through Plasma Membrane Ca2+-Permeable Channels Is Stimulated by H2O2 and H+-ATPase in Ectomycorrhizal Populus × canescens under Cadmium Stress

Abstract

Using a Non-invasive Micro-test Technique, flux profiles of Cd 2+ , Ca 2+ , and H + were investigated in axenically grown cultures of two strains of Paxillus involutus (MAJ and NAU), ectomycorrhizae formed by these fungi with the woody Cd 2+ -hyperaccumulator, Populus canescens, and non-mycorrhizal (NM) roots. The influx of Cd 2+ increased in fungal mycelia, NM and ectomycorrhizal (EM) roots upon a 40-min shock, after short-term (ST, 24 h), or long-term (LT, 7 days) exposure to a hydroponic environment of 50 2 2