摘要
真菌-细菌生物膜(FBB)在制备高效生物肥料接种剂和生防制剂中发挥着重要作用,探讨FBB的形成机理非常有必要。以双孢蘑菇和恶臭假单胞菌UW4为对象,研究了1-氨基环丙烷-1-羧酸(ACC)在双孢蘑菇-细菌生物膜形成过程中的作用。采用PDA平板培养双孢蘑菇菌丝,在距离菌丝尖端边缘处涂布UW4菌悬液,双孢蘑菇菌丝生长速度比涂布超纯水的对照组提高10.85%,同时,显微镜和扫描电镜均可观察到UW4能够在双孢蘑菇菌丝表面形成菌膜。使用ACC合成酶抑制剂氨基氧乙酸(AOA)抑制双孢蘑菇菌丝ACC的合成,则UW4不能在双孢蘑菇菌丝表面形成菌膜。此外,UW4 ACC脱氨酶基因缺失突变株也不能形成菌膜。趋化试验发现,UW4可趋化ACC,趋化强度与双孢蘑菇菌丝分泌物中的强趋化物谷氨酰胺和柠檬酸类似,且ACC最适趋化浓度的趋化强度高于谷氨酰胺和柠檬酸最适趋化浓度的趋化强度。而UW4 ACC脱氨酶基因缺失突变株不能趋化ACC。转录组测序分析ACC对UW4基因表达的影响,发现ACC能够引起UW4中趋化和运动相关基因的表达水平发生显著的上调或下调。以上结果表明,ACC是假单胞菌趋化双孢蘑菇的一种强趋化物质,同时是产ACC脱氨酶细菌在真菌菌丝表面形成菌膜的关键信号物质。
The fungal-bacterial biofilm(FBB) has been considered to play crucial roles in preparing high efficient biofertilizer inoculants and biocontrol agents. However, large scale preparation of FBB is time-consuming and difficult. It is essential to explore the mechanism of FBB forming. The role of 1-aminocyclopropane-1-carboxylate(ACC) on forming Agaricus bisporus-bacterial biofilm was studied by using A. bisporus and Pseudomonas putida UW4. On PDA plates, the mycelial growth rate of A. bisporus with UW4 suspension spreaded on edges of the mycelia improved 10.85%, compared to that with ultrapure water. Furthermore, the biofilm formed by UW4 on A. bisporus mycelial surface could be detected by microscopic examination and scanning electron microscope obserbation. In contrast, both UW4 and its ACC deaminase deficient mutant could not form biofilm on the surface of A. bisporus mycelia treated with the aminooxyacetic acid(AOA), the ACC synthase inhibitor. Moreover, the results of chemotactic assays showed UW4 was chemotactic towards ACC, and the chemotactic response of UW4 to ACC was similar to that of the glutamine and citric acid secreted by A. bisporus mycelia. The chemotactic ability of UW4 to ACC on the optimum ACC concentration was significantly higher than that of glutamine and citric acid, whereas the UW4-AcdS^- showed absence of chemotactic towards ACC. In addition, the transcriptome sequencing analysis revealed that ACC could induce the up-regulation or down-regualtion of chemotactic-and movement-related genes of UW4. Taken together, ACC is a strong chemoattractant for the chemotactic response of P. putida to A. bisporus, and is the critical signaling substance for AcdS-producing bacteria forming biofilm on the fungal mycelial surface.
作者
张朝辉
张广
闻亚美
杨艳青
刘亚非
张会
王振河
邱立友
ZHANG Chaohui;ZHANG Guang;WEN Yamei;YANG Yanqing;LIU Yafei;ZHANG Hui;WANG Zhenhe;QIU Liyou(College of Life Science and Technology,Henan Institute of Science and Technology,Xinxiang 453003,China;Collaborative Innovation Center of Modern Biological Breeding,Henan Province,Xinxiang 453003,China;Zhoukou Academy of Agricultural Sciences,Zhoukou 466000,China;College of Life Sciences,Henan Agricultural University,Zhengzhou 450002,China)
出处
《华北农学报》
CSCD
北大核心
2019年第6期209-218,共10页
Acta Agriculturae Boreali-Sinica
基金
河南省科技攻关项目(162102110009)
国家自然科学基金项目(31902090)
