Arbuscular mycorrhizal symbiosis can mitigate the negative effects of night warming on physiological traits of Medicago truncatula L

Abstract

Elevated night temperature, one of the main climate warming scenarios, can have profound effects on plant growth and metabolism. However, little attention has been paid to the potential role of mycorrhizal associations in plant responses to night warming, although it is well known that symbiotic fungi can protect host plants against various environmental stresses. In the present study, physiological traits of Medicago truncatula L. in association with the arbuscular mycorrhizal (AM) fungus Rhizophagus irregularis were investigated under simulated night warming. A constant increase in night temperature of 1.53°C significantly reduced plant shoot and root biomass, flower and seed number, leaf sugar concentration, and shoot Zn and root P concentrations. However, the AM association essentially mitigated these negative effects of night warming by improving plant growth, especially through increased root biomass, root to shoot ratio, and shoot Zn and root P concentrations. A significant interaction was observed between R. irregularis inoculation and night warming in influencing both root sucrose concentration and expression of sucrose synthase (SusS) genes, suggesting that AM symbiosis and increased night temperature jointly regulated plant sugar metabolism. Night warming stimulated AM fungal colonization but did not influence arbuscule abundance, symbiosis-related plant or fungal gene expression, or growth of extraradical mycelium, indicating little effect of night warming on the development or functioning of AM symbiosis. These findings highlight the importance of mycorrhizal symbiosis in assisting plant resilience to climate warming.

Influence of arbuscular mycorrhizal colonization on whole‐plant respiration and thermal acclimation of tropical tree seedlings

“…Several studies with temperate species have found that temperature affected AM colonization (Heinemeyer and Fitter 2004;Gavito et al 2005;Hu et al 2015); however, in the current study, AM colonization was independent of growth temperature, although we cannot rule out the possibility of an increase in extraradical hyphal biomass as we only measured root colonization (Hawkes et al 2008).…”

“…2005; Hu et al. 2015); however, in the current study, AM colonization was independent of growth temperature, although we cannot rule out the possibility of an increase in extraradical hyphal biomass as we only measured root colonization (Hawkes et al. 2008).…”

Ecological relevance of strigolactones in nutrient uptake and other abiotic stresses, and in plant-microbe interactions below-ground

“…A negative effect of low temperature was reported in wheat and sorghum, while no effect was observed in rice (Table 1) (Augé et al 2004;Hetrick et al 1984;Liu et al 2013). Conversely, a positive effect of high temperature on the symbiosis has recently been reported in Medicago truncatula (Table 1) (Hu et al 2015). In relation to heavy metals, an inhibitory influence of cadmium on the AM fungus Funneliformis mosseae (formerly Glomus mosseae) was detected in wheat (Table 1), although mycorrhizal plants were more tolerant than non-mycorrhizal (Shahabivand et al 2012).…”

Aspects, problems and utilization of Arbuscular Mycorrhizal (AM) application as bio-fertilizer in sustainable agriculture

“…AM show a wide range of tolerance for abiotic factors, hence they are distributed and active worldwide in almost all ecosystems, soil conditions and environment; though the distribution, tolerance and efficacy vary with AM species and strains ( Aguilera et al., 2015 ; Barbosa et al., 2017 ). It was well documented that, mycorrhizal inoculation with different AM species to plants under low or high temperature stress and different nitrogen level ( Liu et al., 2013 ) able to reduce temperature stress and increase P content compared to non-AM plant ( Liu et al., 2016 ; Hu et al., 2015 ; Mathur et al., 2018 ; Zhu et al., 2017 ). Zhu et al.…”