关键词: 内生细菌, 致病疫霉, 生理变化, 抑制作用

Abstract: In order to understand the inhibitory mechanism of endophytic bacterium HT-6 on Phytophthora infestans, the dual culture method combined with traditional methods were adopted to detect the changes of some active substances, resistant enzyme activities, electrical conductibility, and dissolved oxygen in P. infestans mycelia after inhibition by HT-6 at different times. The results showed that soluble sugar and starch contents increased, and protein content decreased in P. infestans in both treated and untreated groups with the prolonged culture, but the contents of three substances in treatment group were- DOI:10.3969/j.issn.1000-1565.2020.06.010拮抗菌HT-6引起致病疫霉菌体的生理变化侯宁¹,申芬¹,田荟遥¹,李成斌¹,孟翠丽²,蒋继志¹(1. 河北大学 生命科学学院, 河北 保定 071002;2. 邢台医学高等专科学校 基础医学部,河北 邢台 054000)摘 要:为了解核桃内生细菌HT-6对致病疫霉的抑制作用机理,采用对峙培养和传统培养相结合的方法检测了受拮抗菌HT-6抑制不同阶段后致病疫霉菌丝体内部分活性物质、抗性相关酶活、电导率以及溶氧量的变化.结果显示,随对峙培养时间延长,受抑制组与对照组中致病疫霉菌丝体内可溶性糖和淀粉含量虽然均呈增加趋势,蛋白质含量均呈下降趋势,但受抑制组可溶性糖、淀粉及蛋白质含量均远低于对照组,且均在对峙培养第15天时差异最大(P<0.01);受抑制组和对照组菌丝体内苯丙氨酸解氨酶、多酚氧化酶和过氧化物酶3种酶活的变化趋势与上述3种物质的变化趋势相似,但均在培养的第12天达到最高,且受抑制组菌体内3种酶活均远高于对照组,与对照达到极显著差异(P<0.01).此外,受拮抗菌HT-6抑制后致病疫霉菌丝体内的电导率(162.77 μS/cm)显著高于对照组(60.03 μS/cm),而溶氧量(47.13%)显著低于对照组(56.1%).这些结果表明:HT-6菌株可通过抑制或大量消耗致病疫霉菌丝体内部分活性物质,同时增加细胞膜透性、降低呼吸作用实现对致病疫霉菌丝体生长的抑制作用.关键词:内生细菌;致病疫霉;生理变化;抑制作用中图分类号:S435.32 文献标志码:A 文章编号:1000-1565(2020)06-0625-06Physiological changes of Phytophthora infestans caused by antagonistic bacterium HT-6HOU Ning¹, SHEN Fen¹, TIAN Huiyao¹, LI Chengbin¹, MENG Cuili², JIANG Jizhi¹(1.School of Life Sciences, Hebei University, Baoding 071002,China; 2. Department of Basic Medicine, Xingtai Medical College, Xingtai 054000, China)Abstract: In order to understand the inhibitory mechanism of endophytic bacterium HT-6 on Phytophthora infestans, the dual culture method combined with traditional methods were adopted to detect the changes of some active substances, resistant enzyme activities, electrical conductibility, and dissolved oxygen in P. infestans mycelia after inhibition by HT-6 at different times. The results showed that soluble sugar and starch contents increased, and protein content decreased in P. infestans in both treated and untreated groups with the prolonged culture, but the contents of three substances in treatment group were- 收稿日期:2019-06-21 基金项目:河北省自然科学基金资助项目(C 2015201231);公益性(农业)行业科研专项(201303018) 第一作者:侯宁(1992—),女,山西盂县人,河北大学在读硕士研究生,主要从事植物与微生物相互作用的分子机理研究.E-mail:15930297278@163.com 通信作者:孟翠丽(1979—),女,河北巨鹿人,邢台医学高等专科学校讲师,主要从事生物化学研究. E-mail: mclant@163.com蒋继志(1960—),男,宁夏中宁人,河北大学教授,博士生导师,主要从事植物与微生物分子互作机理研究. E-mail:jizhijiang909@163.com第6期侯宁等:拮抗菌HT-6引起致病疫霉菌体的生理变化much lower than that in control group, and the maximum differences between treatment and control were found at 15^th d after dual culture(P<0.01). The changes of PAL, PPO and POD activities in P. infestans in both treatment and control were similar to soluble sugar, starch, and protein, but all three enzyme activities reached peaks at 12^th d for culture. And it was found that three enzyme activities in treated group were much higher than in control group at various culture times(P<0.01). In addition, the electrical conductivity in P. infestans mycelia inhibited by HT-6(162.77 μS/cm)was significantly higher than that in control(60.03 μS/cm), while the dissolved oxygen amount in treatment(47.13%)was significantly lower than that in control(56.1%). These findings suggest that the HT-6 strain inhibits P. infestans mycelia growth via preventing or consuming the partial active substances, and increasing cell membrane permeability and reducing respiration.

Key words: endophytic bacteria, Phytophthora infestans, physiological changes, inhibitory action