ABSTRACT

This study aimed to evaluate effects of Funneliformis mosseae on plant growth and root exudate compositions and contents, soil and root phosphatase activity, soil glomalin concentrations, and thus soil aggregate stability and distribution in trifoliate orange under well-watered (75% of maximum water holding capacity) and drought stress (55% of maximum water holding capacity) conditions. After eight weeks of drought treatment, mycorrhizal fungal inoculation improved plant growth and exhibited altered composition of root exudates than non-inoculated treatment. Mycorrhizal fungal inoculation dramatically increased the relative abundance of phenolics (e.g., 2 H,8 H-Benzo[1,2-b:3,4-b’] dipyran-2-one,8,8-dimethyl), terpenoids (e.g., geijerene), and acids (n-hexadecanoic acid), while notably reduced the relative abundance of alkanes (e.g., tridecane, 2-methyl-), esters (e.g., hexanedioic acid and dimethyl ester), and amides (e.g.,13-docosenamide) in root exudates. Mycorrhizal fungal colonization profoundly increased easily extractable and total glomalin-related soil protein levels under two soil water regimes, which cemented soil macroaggregate (2–4 mm size) formation, thereby, improving soil aggregate stability. Mycorrhizal fungal-inoculated plants represented higher soil acid, alkaline and total phosphatase activities, irrespective of well-watered and drought treatment. The results suggest that mycorrhizal plants had improved root microenvironment to mitigate drought damage through changes in root exudate components along with glomalin, phosphatase, and soil aggregate stability in the mycorrhizosphere.

摘要

本研究旨在评估Funneliformis mosseae的效果在水分充足（最大持水量的 75%）和干旱胁迫（55%最大持水量）条件。经过八周的干旱处理，菌根真菌接种改善了植物的生长，并且与未接种的处理相比，根系分泌物的成分发生了变化。菌根真菌接种显着增加了酚类物质（例如 2 H,8 H-Benzo[1,2-b:3,4-b'] dipyran-2-one,8,8-dimethyl）、萜类化合物（例如，geijerene）和酸（正十六烷酸），同时显着降低了烷烃（例如，十三烷，2-甲基-），酯（例如，己二酸和二甲酯）的相对丰度，根分泌物中的酰胺（例如，13-二十二烯酰胺）。在两种土壤水分状况下，菌根真菌定植显着增加了易于提取的和与球菌素相关的土壤总蛋白水平，这巩固了土壤大团聚体（2-4 毫米大小）的形成，从而提高了土壤团聚体的稳定性。接种菌根真菌的植物代表了较高的土壤酸、碱和总磷酸酶活性，与浇水和干旱处理无关。结果表明，菌根植物改善了根系微环境，通过改变根系分泌物成分以及菌根圈中的球蛋白、磷酸酶和土壤团聚体稳定性来减轻干旱损害。在两种土壤水分状况下，菌根真菌定植显着增加了易于提取的和与球菌素相关的土壤总蛋白水平，这巩固了土壤大团聚体（2-4 毫米大小）的形成，从而提高了土壤团聚体的稳定性。接种菌根真菌的植物代表了较高的土壤酸、碱和总磷酸酶活性，与浇水和干旱处理无关。结果表明，菌根植物改善了根系微环境，通过改变根系分泌物成分以及菌根圈中的球蛋白、磷酸酶和土壤团聚体稳定性来减轻干旱损害。在两种土壤水分状况下，菌根真菌定植显着增加了易于提取的和与球菌素相关的土壤总蛋白水平，这巩固了土壤大团聚体（2-4 毫米大小）的形成，从而提高了土壤团聚体的稳定性。接种菌根真菌的植物代表了较高的土壤酸、碱和总磷酸酶活性，与浇水和干旱处理无关。结果表明，菌根植物改善了根系微环境，通过改变根系分泌物成分以及菌根圈中的球蛋白、磷酸酶和土壤团聚体稳定性来减轻干旱损害。接种菌根真菌的植物代表了较高的土壤酸、碱和总磷酸酶活性，与浇水和干旱处理无关。结果表明，菌根植物改善了根系微环境，通过改变根系分泌物成分以及菌根圈中的球蛋白、磷酸酶和土壤团聚体稳定性来减轻干旱损害。接种菌根真菌的植物代表了较高的土壤酸、碱和总磷酸酶活性，与浇水和干旱处理无关。结果表明，菌根植物改善了根系微环境，通过改变根系分泌物成分以及菌根圈中的球蛋白、磷酸酶和土壤团聚体稳定性来减轻干旱损害。