Ectomycorrhizal Inoculation Enhances the Salt Tolerance of Quercus mongolica Seedlings

Abstract

Salt stress harms the growth and development of plants, and the degree of soil salinization in North China is becoming increasingly severe. Ectomycorrhiza (ECM) is a symbiotic system formed by fungi and plants that can improve the growth and salt tolerance of plants. No studies to date have examined the salt tolerance of Quercus mongolica, a typical ectomycorrhizal tree species of temperate forests in the northern hemisphere. Here, we inoculated Q. mongolica with two ectomycorrhizal fungi (Gomphidius viscidus; Suillus luteus) under NaCl stress to characterize the effects of ECM. The results showed that the symbiotic relationship of Q. mongolica with G. viscidus was more stable than that with S. luteus. The cross-sectional area of roots increased after inoculation with the two types of ectomycorrhizal fungi. Compared with the control group, plant height, soluble sugar content, and soluble protein content of leaves were 1.62, 2.41, and 2.04 times higher in the G. viscidus group, respectively. Chlorophyll (Chl) content, stomatal conductance (Gs), and intracellular CO2 concentration (Ci) were significantly higher in Q. mongolica inoculated with ectomycorrhizal fungi than in the control, but differences in the net photosynthetic rate (Pn), transpiration rate (Tr), and photosystem II maximum photochemical efficiency (Fv/Fm) were lower. The relative conductivity of Q. mongolica inoculated with the two ectomycorrhizal fungi was consistently lower than that of non-mycorrhizal seedlings, with the effect of G. viscidus more pronounced than that of S. luteus. The malondialdehyde (MDA) content showed a similar pattern. Peroxidase (POD) and catylase (CAT) levels in mycorrhizal seedlings were generally higher than those of non-mycorrhizal seedlings under normal conditions, and were significantly higher than those of non-mycorrhizal seedlings on the 36th and 48th day after salt treatment, respectively. Overall, the results indicated that the salt tolerance of Q. mongolica seedlings was improved by ectomycorrhizal inoculation.

Effects of Drought Stress and Rehydration on Physiological and Biochemical Properties of Four Oak Species in China

“…The antioxidant enzymes mainly include peroxidase (POD), superoxide dismutase (SOD), ascorbate oxidase (APX) and catalase (CAT), and the nonenzymatic antioxidant substances mainly include reduced glutathione (GSH), reduced ascorbic acid (AsA) and carotenoids [ 9 ]. Many studies have shown that the responses of different protective enzymes to drought stress vary [ 10 , 11 , 12 ]. The protective enzymes that play a dominant role in plants may also differ between periods of stress [ 13 ].…”

The impact of anthropogenic transformation of urban soils on ectomycorrhizal fungal communities associated with silver birch (Betula pendula Roth.) growth in natural versus urban soils

“…Nevertheless, B. pendula colonisation was stronger than for S. alba (15%) and S. caprea (9%), which may indicate high tolerance of silver birch to environmental stresses. Moreover, as observed by Bai et al 56 in the case of Q. mongolica seedlings, ectomycorrhizal inoculation can improve salt tolerance. Zwiazek et al 57 , examining pine seedlings exposed to NaCl, also found reduced Na accumulation and higher growth rates in the case of seedlings inoculated with urban soil containing specific fungi genera.…”

Morphological and Physiological Responses of Suaeda salsa under Drought and Salt Stress

“…reported the physiological mechanisms of exogenous ABA regulation of drought stress in ginger, observed increased activities of SOD, POD, and CAT in plant leaves upon early application of ABA to the roots. In our study, POD activity in S. salsa initially decreased insigni cantly and then increased with the increasing severity of drought stress, which may be because different antioxidant enzymes have different responses to drought stress(Anjum et al 2011;Bai et al 2021). Protective enzymes that play a dominant role in plants may also differ under stress(Seki et al 2007).…”