Arbuscular mycorrhizal fungi modify nutrient allocation and composition in wheat (Triticum aestivum L.) subjected to heat-stress
2016
Cabral, Carmina | Ravnskov, Sabine | Tringovska, Ivanka | Wollenweber, Bernd
AIMS: To evaluate the role of the AM symbiosis on nutrient allocation in Triticum aestivum L. cv. 1110 at different growth stages before and after heat-stress at anthesis. METHODS: Measurements of plant biomass and grain yield at anthesis, grain-filling and maturity; determination of macro- and micronutrient concentrations in aboveground biomass; evaluation of AM fungal structures in roots and assessment of light-use efficiency of plants. RESULTS: AM increased grain number in wheat under heat-stress, and altered nutrient allocation and tiller nutrient composition. Heat increased number of arbuscules in wheat root, whereas number of vesicles and total colonization were unaffected. Heat increased photosystem II yield and the electron transfer rate, whereas non-photochemical quenching decreased during the first 2 days of heat-stress. CONCLUSIONS: Nutrient allocation and –composition in wheat grown under heat-stress were altered by AM symbiosis, which lowered the K/Ca ratio, whereas it was increased by heat-stress. The increased carbon availability in spikes at this developmental stage, related to the C sink strength of the AM symbiosis and its influence on source-sink relationships in the host-plant, resulted in increased number of grains in heat-stressed AM plants.
显示更多 [+] 显示较少 [-]