接种丛枝菌根真菌对柑橘生长与次生代谢的影响

Effects of Arbuscular Mycorrhizal Fungi on Plant Growth and Secondary Metabolism in Citrus reticulata

摘要:

为了解丛枝菌根（AM）真菌对根、根系分泌物中次生代谢物和植物生长的影响，以AM真菌（Glomus epigaeum）接种柑橘（Citrus reticulata），对柑橘的酚类物质、抗氧化酶和生长情况进行研究。结果表明，温室盆栽6个月后，接种AM真菌显著提高柑橘酚酸类物质的积累，但是酚酸组分在根和根分泌物中存在差异，根中原儿茶酸和丁香酸含量为29.98和18.32μg/g，分别是未接种的4.58和2.26倍。而根系分泌物中香豆酸、苯甲酸和根皮苷含量为0.36、6.04和12.32 μg/g，分别是未接种的1.71、1.94和1.25倍，而香草醛仅在未接种柑橘根中检测到。接种AM真菌的柑橘苯丙氨酸解氨酶、多酚氧化酶和过氧化物酶活性为38.36、0.51和28.62 U/（g·min），分别是未接种AM真菌的1.99、2.83和3.10倍。同时菌根定殖也显著提高柑橘的株高、茎粗和叶片数。因此，AM真菌定殖能促进植物生长，改变柑橘次生代谢产物的积累。

Abstract:

To understand the effect of arbuscular mycorrhizal (AM) fungi on secondary metabolism in root and root exudates and plant growth, Citrus reticulata was inoculated by AM fungus Glomus epigaeum, the phenolic, antioxidant enzyme and growth of C. reticulata were studied. After six months cultured in greenhouse, the concentrations of phenolic acids in C. reticulata inoculated with AM fungus significantly increased. However, the components of phenolic acid were different in root and root exudates, the contents of protocatechunic acid and syringic acid in roots was 29.98 and 18.32 μg/g, which were 4.58 and 2.26 times higher than those in control, respectively. The contents of coumaric acid, benzoic acid and phloridzin were 0.36, 6.04 and 12.32 μg/g, respectively, which were 1.71, 1.94 and 1.25 times higher than those in control. Whereas vanillin was only detected in uninoculated roots. The enzyme activities of phenylalnine ammonia-lyase, polyphenol oxidase and peroxidase in C. reticulata inoculated with AM fungus were 38.36, 0.51 and 28.62 U/(g·min), respectively, which were 1.99, 2.83 and 3.10 times higher than those in control. In addition, the height, stem diameter and leaf number of C. reticulata inoculated with arbuscular mycorrhizal fungi also significantly increased. It was suggested that AM colonization could significantly affected the growth and secondary metabolites in C. reticulata.