ABSTRACT

It is well documented that sole application of potassium (K) or mycorrhizal fungi can alleviate heavy metal stress in plants. As an indicator of the efficient defense in the mycorrhizal fungi-plant system, glomalin synthesis in the rhizosphere can be determined. In this study, interactive effects of mycorrhizal fungi (MY) and K on glomalin content, heavy metal uptake and mycorrhizal properties of sunflower plants were examined with three soil K levels (0, 100, and 200 mg K kg⁻¹ using K₂SO₄). The three levels of mycorrhization are: i) no mycorrhizal inoculation, ii) Rhizophagus irregularis inoculation, and iii) mixed mycorrhizal inoculum application. Joint application of potassium and mycorrhiza significantly increased the percentage of root colonization and easily extractable glomalin (EEG), showing 56% root colonization in the treatment of K100 + mixed mycorrhiza and 178 µg EEG g⁻¹ in the treatment of K200 + mixed mycorrhiza. Joint application of MY and K significantly reduced the translocation of heavy metals to the shoot of the plants. The highest total uptake of Zn by plants per pot (2.01 mg pot ⁻¹) and Pb (0.78 mg pot ⁻¹) were found in non-mycorrhizal plants. The MY and K treatments also increased the chlorophyll content and leaf area index by 57%. This study concluded that application of potassium and mycorrhizal fungi enhanced glomalin production and increased plant resistance to heavy metal stress.

摘要

有充分证据表明，单独施用钾 (K) 或菌根真菌可以减轻植物中的重金属胁迫。作为菌根真菌-植物系统中有效防御的指标，可以确定根际中的glomalin合成。在这项研究中，使用 K ₂ SO在三种土壤 K 水平（0、100 和 200 mg K kg ^-1 ₄）。菌根化的三个层次是：i) 不接种菌根，ii)不规则根霉接种，和 iii) 混合菌根接种。钾和菌根的联合应用显着增加了根部定植率和易提取球蛋白 (EEG)，在 K100 + 混合菌根处理中显示 56% 的根部定植率，在K200 + 混合菌根处理中显示178 µg EEG g ^{-1的根部定植率。}MY和K的联合施用显着减少了重金属向植物茎部的转移。每盆植物对 Zn 的最高总吸收量（2.01 mg pot ^-1）和 Pb（0.78 mg pot ^-1) 在非菌根植物中发现。MY 和 K 处理也使叶绿素含量和叶面积指数增加了 57%。该研究得出结论，钾和菌根真菌的应用增强了球蛋白的产生并增加了植物对重金属胁迫的抵抗力。