抗氧化剂对猪苓菌丝形成菌核的影响

摘要

Objective To investigate the effect of vitamin C (Vc) and NADPH oxidase inhibitor apocynin (Apo) on P. umbellatus sclerotial formation in nutritional agar medium and to study the relationship between antioxidants and ROS generation during P. umbellatus sclerotial formation. Methods After different volumes of Vc solution was added to the sterilized and cooled maltose agar medium, the final concentration of the Vc solution was adjusted to 0.5, 1.0, 2.0, 5.0, 10 and 15 mg/ml respectively in the final medium. The final concentration of Apo solution of 10, 20 and 40 mmol/L was made respectively by adding different volumes of Apo mother liquor (100 mmol/L) to the maltose agar medium. Fresh P. umbellatus sclerotial biomass was measured to evaluate the effect of antioxidants on P. umbellatus sclerotial formation. ROS production of sclerotia and mycelia was detected using NBT reduction method. Results Low concentration of Vc of 0.5 mg/ml could promote P. umbellatus mycelial growth and induce sclerotial formation forming from mycelia, with the fresh biomass of the sclerotia accumulated to (1.69 ± 0.06) g/ 20g substrate. Compared with the control group without Vc with the fresh sclerotia biomass of (1.55 ± 0.10) g/ 20 g substrate, the biomass of the two groups was of no significant difference (P > 0.05). High concentrations of Vc above 5.0 mg/ml (5.0、10 and 15 mg/ml) inhibited the fungus growth and sclerotial differentiation as well. Each concentration of Apo of 10, 20 and 40 mmol/L inhibited P. umbellatus mycelial growth and hindered sclerotial formation as well. Conclusion Reactive oxygen species play an important role in P. umbellatus sclerotial formation in Petri dishes. ROS in mycelia should be accumulated to such an extent to induce sclerotial differentiation from mycelia. Antioxidants of certain concentrations eliminate ROS to a certain extent and decrease the biomass of sclerotia or could not induce slcerotial formation.%　　目的旨在考察抗氧化剂维生素 C（Vc）及 NADPH 氧化酶抑制剂 apocynin（Apo）在营养琼脂培养基中对猪苓菌丝形成菌核的影响，并探讨抗氧化剂对猪苓菌丝形成菌核过程中活性氧产生的影响。方法将不同体积的 Vc 母液分别加入到灭菌后冷却至60℃左右的麦芽糖琼脂培养基中，使 Vc 在培养基中的终浓度分别为0.5、1.0、2.0、5.0、10、15 mg/ml。将 Apo 配制成100 mmol/L 的母液，加入到灭菌后冷却至60℃左右的麦芽糖琼脂培养基中，使其在培养基中的终浓度分别为10、20、40 mmol/L。通过猪苓菌核生物量来评价抗氧化剂对猪苓菌核形成的影响；利用 NBT 还原法检测猪苓菌核形成过程中菌丝及菌核内活性氧的含量。结果低浓度（0.5 mg/ml）的 Vc 组能够促进猪苓菌丝生长并促使猪苓菌丝形成菌核，菌核生物量为（1.69±0.06）g/20 g 基质，与不添加 Vc 的对照组[菌核生物量为（1.55±0.10）g/20 g 基质）]相比，所诱导产生的猪苓菌核生物量无显著性差异（P >0.05）；终浓度为5.0、10、15 mg/ml 的Vc 组对猪苓菌丝生长及菌核形成均具有抑制作用。任一浓度的 Apo（10、20、40 mmol/L）均使猪苓菌丝生长明显减缓，并且不能诱导猪苓菌核形成。结论营养琼脂培养基中生长的猪苓菌丝内氧化应激水平达到一定的水平才可能促使猪苓菌丝向菌核分化；抗氧化剂在一定程度上消除了活性氧，使猪苓菌核形成减少或不能形成。