Mycorrhizal colonisation and P-supplement effects on N uptake and N assimilation in perennial ryegrass under well-watered and drought-stressed conditions
- 15 February 2012
- journal article
- Published by Springer Science and Business Media LLC in Mycorrhiza
- Vol. 22 (7), 525-534
- https://doi.org/10.1007/s00572-012-0430-6
Abstract
To compare the effect of arbuscular mycorrhiza (AM) and P-supplement on N uptake and N assimilation under well-watered or drought-stressed conditions, Glomus intraradices-colonised, P-supplemented non-mycorrhizal (P) and non-mycorrhizal (control) plants of Lolium perenne were exposed to 12 days of water treatment. Leaf water potential (Ψ w), photosynthetic ability, and N and P nutritional status were measured at the beginning (day 0) and end (day 12) of water treatment. N absorption, amino acid and protein synthesis were quantified using the isotopic tracer 15N at day 12. Under well-watered conditions, growth response and physiological parameters were similar in AM and P plants, as compared to controls. Drought (10% water) significantly decreased these parameters in all three treatments. As compared to control plants, the negative impact of water deficit on the Ψ w, photosynthesis, biomass, and N and P content was highly alleviated in AM plants, while only slightly improved or remained the same level in P plants. The effect of AM symbiosis on N absorption and N assimilation was greater than that of the P supplement under well-watered and drought-stressed conditions, and this effect was highly enhanced under drought-stressed conditions. At terminal drought stress on day 12, the effect of AM colonisation on de novo synthesis of amino acids and proteins was 4.4- and 4.8-fold higher than that of the P supplement. These results indicate that the AM symbiosis plays an integrative role in N nutrition by alleviating the negative impacts of drought on N or P uptake and N assimilation, whereas the efficiency of a direct P supplement is very limited under drought-stressed conditions.Keywords
This publication has 37 references indexed in Scilit:
- Nutrient acquisition in mycorrhizal lettuce plants under different phosphorus and nitrogen concentrationPlant Science, 2003
- Water relations, drought and vesicular-arbuscular mycorrhizal symbiosisMycorrhiza, 2001
- Activity of nitrate reductase and glutamine synthetase in shoot and root of mycorrhizal Allium cepaPlant Science, 1998
- Effects of mycorrhizal infection on drought tolerance and recovery in safflower and wheatPlant and Soil, 1997
- Physiological and nutritional responses by Lactuca Sativa L. to nitrogen sources and mycorrhizal fungi under drought conditionsBiology and Fertility of Soils, 1996
- Ammonia Assimilation in Zea mays L. Infected with a Vesicular-Arbuscular Mycorrhizal Fungus Glomus fasciculatumPlant Physiology, 1993
- Comparison of protein patterns in non‐mycorrhizal and vesicular–arbuscular mycorrhizal roots of red cloverNew Phytologist, 1993
- Drought resistance of mycorrhizal pepper plants independent of leaf P concentration ‐ response in gas exchange and water relationsPhysiologia Plantarum, 1993
- Root hydraulic conductivity of vesicular–arbuscular mycorrhizal green ash seedlingsNew Phytologist, 1988
- INFLUENCE OF VESICULAR‐ARBUSCULAR MYCORRHIZAE ON WATER MOVEMENT THROUGH BOUTELOUA GRACILIS (H.B.K.) LAG EX STEUD*New Phytologist, 1982