Abstract: As a main body of terrestrial ecosystem, forest is a major receptor of acid rain pollution. Acid rain has severe impact on forest ecosystem. Ectomycorrhizal fungi symbiose with plant roots, and protect their hosts against various aggressions, including that from acid rain. Many of the macrofungi form symbiotic ectomycorrhizae with forest trees, playing an important role in maintaining the nutrient balance of the trees and protecting the trees against pathogens. This paper reviewed the research advances in the relationships between mycorrhizae and acid rain. Acid rain can inhibit and reduce ectomycorrhizal formation and vitality, whereas ectomycorrhizae can alleviate the damage of acid rain to host plants and improve the hosts’ tolerance against acid rain. The ectomycorrhizae-induced mitigation mechanisms against the acid rain stress on plants are: 1) physical shielding effect of ectomycorrhizal morphological structure, 2) promoting host plant nutrient uptake and increasing host plant acid-defense capability, 3) improving host plant enzyme activities and host plant viability, and 4) secreting organic acids or other substances.

Key words: tomato, nitric oxide, copper stress, PCs, GSH.