State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Haidian District, No. 18, Shuangqing Road, Beijing, 100085, People's Republic of China.
University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China.
Mycorrhiza. 2022 Jan;32(1):33-43. doi: 10.1007/s00572-021-01059-w. Epub 2022 Jan 4.
Enriched surface ozone (O) can impose harmful effects on plants. Conversely, arbuscular mycorrhizal (AM) symbiosis can enhance plant tolerance to various environmental stresses and facilitate plant growth. The interaction of AM fungi and O on plant performance, however, seldom has been investigated. In this study, alfalfa (Medicago sativa L.) was used as a test plant to study the effects of O and AM symbiosis on plant physiology and growth under two O levels (ambient air and elevated O with 60 nmol·mol O enrichment) and three AM inoculation treatments (inoculation with exogenous or indigenous AM fungi and non-inoculation control). The results showed that elevated O decreased plant net photosynthetic rate and biomass, and increased malondialdehyde concentration, while AM inoculation (with both exogenous and indigenous AM fungi) could promote plant nutrient acquisition and growth irrespective of O levels. The positive effects of AM symbiosis on plant nutrient acquisition and antioxidant enzyme (superoxide dismutase and peroxidase) activities were most likely offset by increased stomatal conductance and O intake. As a result, AM inoculation and O generally showed no significant interactions on plant performance: although elevated O did not diminish the beneficial effects of AM symbiosis on alfalfa plants, AM symbiosis also did not alleviate the harmful effects of O on plants.
富氧（O）会对植物造成有害影响。相反，丛枝菌根（AM）共生可以增强植物对各种环境胁迫的耐受性并促进植物生长。然而，AM 真菌和 O 对植物性能的相互作用很少被研究过。在这项研究中，紫花苜蓿（Medicago sativa L.）被用作测试植物，以研究在两种 O 水平（环境空气和 60 nmol·mol O 富氧）和三种 AM 接种处理（接种外生或内生 AM 真菌和未接种对照）下，O 和 AM 共生对植物生理和生长的影响。结果表明，O 富化降低了植物的净光合速率和生物量，增加了丙二醛浓度，而 AM 接种（外生和内生 AM 真菌）无论 O 水平如何都可以促进植物养分的获取和生长。AM 共生对植物养分获取和抗氧化酶（超氧化物歧化酶和过氧化物酶）活性的积极影响很可能被增加的气孔导度和 O 摄取所抵消。因此，AM 共生和 O 通常对植物性能没有显著的相互作用：虽然 O 富化没有减弱 AM 共生对紫花苜蓿的有益影响，但 AM 共生也没有减轻 O 对植物的有害影响。
