State Key Laboratory of Subtropical Silviculture, Zhejiang A & F University, Hangzhou, Zhejiang, 311300, China.
College of Forestry, Beijing Forestry University, Beijing, 100083, China.
Environ Sci Pollut Res Int. 2022 Apr;29(20):29904-29916. doi: 10.1007/s11356-021-18248-x. Epub 2022 Jan 7.
Lespedeza formosa is an economically important shrub in the agroecosystems of southern China, where acid rain (AR) is an increasingly serious environmental issue. However, the roles of arbuscular mycorrhizal fungi (AMF) in adapting the plants to AR stress are poorly understood. In this study, L. formosa seedlings were cultivated in a greenhouse, where the inoculated (colonization with Rhizophagus irregularis and Diversispora versiformis, alone and in combination) and non-inoculated plants were treated with three AR regimes (pH 5.6, 4.0, and 2.5) to evaluate the roles of AMF under acidic conditions. The results showed that AR individually suppressed plant growth by inhibiting photosynthetic parameters and induced Al phytotoxicity in non-mycorrhizal plants. However, mycorrhizal inoculation, especially in combination, significantly increased the total dry weight, photosynthetic capabilities, shoot nitrogen (N) concentration (average 15.8 and 16.7 mg g for non-mycorrhizal and mycorrhizal plants, respectively) and plant phosphorus (P) concentration (average 1.6 and 2.3 mg g for non-mycorrhizal and mycorrhizal plants, respectively) at pH 4.0, reduced N/P ratio (average 9.5 and 6.9 for non-mycorrhizal and mycorrhizal plants, respectively) at pH 4.0, and protected roots against Al phytotoxicity (average 2.0 and 1.4 mg g for non-mycorrhizal and mycorrhizal roots, respectively), indicating that AMF could mitigate some of the detrimental effects of AR. Moreover, our findings suggest that AMF mainly benefited the plant through the combined effects of N concentrations and N/P ratios in shoots and Al concentrations in roots under acidic conditions.
美丽胡枝子是中国南方农业生态系统中一种具有重要经济价值的灌木，而酸雨（AR）是一个日益严重的环境问题。然而，丛枝菌根真菌（AMF）在植物适应 AR 胁迫方面的作用还知之甚少。在这项研究中，将美丽胡枝子幼苗在温室中进行培养，接种（单独接种和混合接种泡囊丛枝菌和轮枝菌）和未接种的植物分别用三种 AR 处理（pH5.6、4.0 和 2.5），以评估在酸性条件下 AMF 的作用。结果表明，AR 单独处理通过抑制光合参数来抑制植物生长，并在非菌根植物中诱导铝的植物毒性。然而，菌根接种，尤其是混合接种，显著增加了总干重、光合能力、地上部氮（N）浓度（非菌根和菌根植物分别为平均 15.8 和 16.7mg/g）和植物磷（P）浓度（非菌根和菌根植物分别为平均 1.6 和 2.3mg/g）在 pH4.0 时，降低了 N/P 比（非菌根和菌根植物分别为平均 9.5 和 6.9）在 pH4.0 时，保护根系免受铝的植物毒性（非菌根和菌根根分别为平均 2.0 和 1.4mg/g），表明 AMF 可以减轻 AR 的一些不利影响。此外，我们的研究结果表明，在酸性条件下，AMF 主要通过地上部氮浓度和 N/P 比以及根系铝浓度的综合作用来促进植物的生长。
