Arbuscular mycorrhizal colonization reduces arsenate uptake in barley via downregulation of transporters in the direct epidermal phosphate uptake pathway
Article first published online: 14 SEP 2009
© The Authors (2009). Journal compilation © New Phytologist (2009)
Special Issue: Featured papers on ‘Weeds - bridging the gap between evolutionary ecology and crop science’
Volume 184, Issue 4, pages 962–974, December 2009
How to Cite
Christophersen, H. M., Smith, F. A. and Smith, S. E. (2009), Arbuscular mycorrhizal colonization reduces arsenate uptake in barley via downregulation of transporters in the direct epidermal phosphate uptake pathway. New Phytologist, 184: 962–974. doi: 10.1111/j.1469-8137.2009.03009.x
- Issue published online: 6 NOV 2009
- Article first published online: 14 SEP 2009
- Received: 14 June 2009, Accepted: 20 July 2009
- barley (Hordeum vulgare);
- mycorrhizal fungi;
- Glomus intraradices;
- gene expression
- •Here, we used barley (Hordeum vulgare) grown in normal and compartmented pots to investigate sensitivity to arsenic (As) in the absence of a positive growth response to arbuscular mycorrhizas (AM).
- •We tested the hypothesis that upon inoculation with AM fungi downregulation of HvPht1;1 and HvPht1;2 genes (encoding high-affinity inorganic orthophosphate (Pi)-uptake systems in a direct pathway via root epidermis and root hairs) and upregulation of the AM-induced HvPht1;8 (encoding the Pi-uptake system responsible for transfer of Pi from the symbiotic interface to cortical cells) play a role in decreased As uptake and hence reduced As sensitivity in AM plants.
- •Barley did not respond, or responded negatively to colonization by Glomus intraradices in terms of growth. In terms of specific phosphorus (P) uptake (P uptake per g of root) barley was nonresponsive. There was a significant interaction between As treatment and colonization, resulting in a lower As concentration and uptake in AM compared with nonmycorrhizal (NM) plants.
- •The decreased uptake of As and higher P : As molar ratios in the AM barley can be explained by the operation of the AM pathway as indicated by induction of HvPht1;8 and by down-regulation of HvPht1;1 and HvPht1;2.