Record ID No. |
6080 |
Author(s) |
Sa G.*, Yao J., Deng C., Liu J., Zhang Y., Zhu Z., Zhang Y., Ma X., Zhao R., Lin S., Lu C., Polle A. an Chen S. , 2019 |
Affiliation |
*Beijing advanced Innovation Centre for Tree Breeding by Molecular Design, College of Biological Sciences and Technology, Beijing Forestry University, Box 162, Beijing, 100083 China. |
Title |
Amelioration of nitrate uptake under salt stress by ectomycorrhiza with and without a Hartig Net. |
Source. Vol.(no):Page |
New Phytologist. 222(4): 1951-1964. |
Categories |
Ectomycorrhiza |
Subjects |
Biochemistry Ecology Physiology |
Sub-subjects |
Nutrition Soil reaction |
Host |
Populus × canescens |
Organism |
Paxillus involutus |
Country |
China |
Abstracts |
Salt stress is an important environmental cue impeding poplar nitrogen nutrition. Here, we characterized the impact of salinity on proton‐driven nitrate fluxes in ectomycorrhizal roots and the importance of a Hartig net for nitrate uptake. We employed two Paxillus involutus strains for root colonization: MAJ, which forms typical ectomycorrhizal structures (mantle and Hartig net), and NAU, colonizing roots with a thin, loose hyphal sheath. Fungus‐colonized and noncolonized Populus × canescens were exposed to sodium chloride and used to measure root surface pH, nitrate (NO3−) flux and transcription of NO3− transporters (NRTs; PcNRT1.1, ‐1.2, ‐2.1), and plasmalemma proton ATPases (HAs; PcHA4, ‐8, ‐11). Paxillus colonization enhanced root NO3− uptake, decreased surface pH, and stimulated NRTs and HA4 of the host regardless the presence or absence of a Hartig net. Under salt stress, noncolonized roots exhibited strong net NO3− efflux, whereas beneficial effects of fungal colonization on surface pH and HAs prevented NO3− loss. Inhibition of HAs abolished NO3− influx under all conditions. We found that stimulation of HAs was crucial for the beneficial influence of ectomycorrhiza on NO3− uptake, whereas the presence of a Hartig net was not required for improved NO3− translocation. Mycorrhizas may contribute to host adaptation to salt‐affected environments by keeping up NO3− nutrition. |