Institute of Applied Biotechnology, School of Life Science, Shanxi Datong University, Datong, Shanxi, China.
State Key Laboratory of Tree Genetics and Breeding, Research Institute of Tropical Forestry, Chinese Academy of Forestry, Guangdong, China.
PLoS One. 2021 Nov 23;16(11):e0259959. doi: 10.1371/journal.pone.0259959. eCollection 2021.
The role of arbuscular mycorrhizal (AM) fungus (Rhizophagus intraradices) in the amelioration of the water deficit-mediated negative influence on the growth, photosynthesis, and antioxidant system in Euonymus maackii Rupr. was examined. E. maackii seedlings were subjected to 5 water deficit levels, soil water contents of 20%, 40%, 60%, 80% and 100% field capacity (FC), and 2 inoculation treatments, with and without AM inoculation. The water deficit increasingly limited the seedling height, biomass accumulation in shoots and roots, chlorophyll content, gas exchange and chlorophyll fluorescence parameters with an increasing water deficit level. In addition, water deficit stimulated the activities of antioxidant enzymes, including superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), in both shoots and roots, except under 20% FC conditions. E. maackii seedlings under all water deficit conditions formed symbiosis well with AM fungi, which significantly ameliorated the drought-mediated negative effect, especially under 40% and 60% FC conditions. Under 40% to 80% FC conditions, AM formation improved seedling growth and photosynthesis by significantly enhancing the biomass accumulation, chlorophyll content and assimilation. Mycorrhizal seedlings showed better tolerance and less sensitivity to a water deficit, reflected in the lower SOD activities of shoots and roots and CAT activity of shoots under 40% and 60% FC conditions. Downregulation of the antioxidant system in mycorrhizal seedlings suggested better maintenance of redox homeostasis and protection of metabolism, including biomass accumulation and assimilation. All the results advocated the positive role of R. intraradices inoculation in E. maackii against a water deficit, especially under 40% FC, which suggested the distinct AM performance in drought tolerance and the potential role of the combination of E. maackii-AM fungi in ecological restoration in arid regions.
研究了丛枝菌根（AM）真菌（内根结球囊霉）在改善水分亏缺对黄檗幼苗生长、光合作用和抗氧化系统的负面影响中的作用。将黄檗幼苗置于 5 个水分亏缺水平下，土壤含水量分别为 20%、40%、60%、80%和 100%田间持水量（FC），并进行 2 种接种处理，接种和不接种 AM。随着水分亏缺程度的增加，幼苗的高度、地上部和根生物量积累、叶绿素含量、气体交换和叶绿素荧光参数受到越来越大的限制。此外，水分亏缺刺激了抗氧化酶的活性，包括超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT），在地上部和根中都有，除了在 20% FC 条件下。在所有水分亏缺条件下，黄檗幼苗与 AM 真菌形成了良好的共生关系，这显著改善了干旱介导的负面影响，特别是在 40%和 60% FC 条件下。在 40%至 80% FC 条件下，AM 的形成通过显著增强生物量积累、叶绿素含量和同化作用，改善了幼苗的生长和光合作用。在 40%和 60% FC 条件下，接种了 AM 的幼苗的 SOD 活性在地上部和根中较低，CAT 活性在地上部较低，表明其对水分亏缺的耐受性更好，敏感性更低。接种 AM 的幼苗的抗氧化系统下调表明其更好地维持了氧化还原平衡，保护了代谢，包括生物量积累和同化。所有结果都证明了 R. intraradices 接种在黄檗抵御水分亏缺中的积极作用，特别是在 40% FC 下，这表明 AM 在耐旱性方面表现出色，以及黄檗-AM 真菌组合在干旱地区生态恢复中的潜在作用。
