Zhou Hong-Yin, Nian Fu-Zhao, Chen Bao-Dong, Zhu Yong-Guan, Yue Xian-Rong, Zhang Nai-Ming, Xia Yun-Sheng
College of Resources and Environment, Yunnan Agricultural University, Kunming 650201, China.
College of Plant Protection, Yunnan Agricultural University, Kunming 650201, China.
J Fungi (Basel). 2023 Jun 15;9(6):677. doi: 10.3390/jof9060677.
Arbuscular mycorrhizal fungi (AMF) play key roles in enhancing plant tolerance to heavy metals, and iron (Fe) compounds can reduce the bioavailability of arsenic (As) in soil, thereby alleviating As toxicity. However, there have been limited studies of the synergistic antioxidant mechanisms of AMF () and Fe compounds in the alleviation of As toxicity on leaves of maize ( L.) with low and moderate As contamination. In this study, a pot experiment was conducted with different concentrations of As (0, 25, 50 mgꞏkg) and Fe (0, 50 mgꞏkg) and AMF treatments. Results showed that under low and moderate As concentrations (As25 and As50), the co-inoculation of AMF and Fe compound significantly increased the biomass of maize stems and roots, phosphorus (P) concentration, and P-to-As uptake ratio. Moreover, the co-inoculation of AMF and Fe compound addition significantly reduced the As concentration in stem and root, malondialdehyde (MDA) content in leaf, and soluble protein and non-protein thiol (NPT) contents in leaf of maize under As25 and As50 treatments. In addition, co-inoculation with AMF and Fe compound addition significantly increased the activities of catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) in the leaves of maize under As25 treatment. Correlation analysis showed that stem biomass and leaf MDA content were very significantly negatively correlated with stem As content, respectively. In conclusion, the results indicated that the co-inoculation of AMF and Fe compound addition can inhibit As uptake and promote P uptake by maize under low and moderate As contamination, thereby mitigating the lipid peroxidation on maize leaves and reducing As toxicity by enhancing the activities of antioxidant enzymes under low As contamination. These findings provide a theoretical basis for the application of AMF and Fe compounds in the restoration of cropland soil contaminated with low and moderate As.
丛枝菌根真菌（AMF）在增强植物对重金属的耐受性方面发挥着关键作用，铁（Fe）化合物可以降低土壤中砷（As）的生物有效性，从而减轻砷的毒性。然而，关于AMF和铁化合物在缓解低、中度砷污染对玉米（Zea mays L.）叶片砷毒性方面的协同抗氧化机制的研究还很有限。在本研究中，进行了一项盆栽试验，设置了不同浓度的砷（0、25、50 mg·kg⁻¹）、铁（0、50 mg·kg⁻¹）和AMF处理。结果表明，在低、中度砷浓度（As25和As50）下，AMF与铁化合物共同接种显著增加了玉米茎和根的生物量、磷（P）浓度以及P/As吸收比。此外，在As25和As50处理下，AMF与铁化合物共同接种显著降低了玉米茎和根中的砷浓度、叶片中的丙二醛（MDA）含量以及叶片中的可溶性蛋白和非蛋白硫醇（NPT）含量。另外，在As25处理下，AMF与铁化合物共同接种显著提高了玉米叶片中过氧化氢酶（CAT）、过氧化物酶（POD）和超氧化物歧化酶（SOD）的活性。相关性分析表明，茎生物量和叶片MDA含量分别与茎中砷含量极显著负相关。总之，结果表明，在低、中度砷污染条件下，AMF与铁化合物共同接种可以抑制玉米对砷的吸收并促进对磷的吸收，从而减轻玉米叶片的脂质过氧化，并通过增强低砷污染下抗氧化酶的活性来降低砷的毒性。这些发现为AMF和铁化合物在低、中度砷污染农田土壤修复中的应用提供了理论依据。
