College of Life Sciences, Shandong Engineering Research Center of Plant-Microbia Restoration for Saline-Alkali Land, Shandong Key Laboratory of Agricultural Microbiology, National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, Shandong Agricultural University, Tai'an, 271018, China.
BMC Microbiol. 2021 Mar 4;21(1):70. doi: 10.1186/s12866-021-02132-2.
Paenibacillus polymyxa SC2, a bacterium isolated from the rhizosphere soil of pepper (Capsicum annuum L.), promotes growth and biocontrol of pepper. However, the mechanisms of interaction between P. polymyxa SC2 and pepper have not yet been elucidated. This study aimed to investigate the interactional relationship of P. polymyxa SC2 and pepper using transcriptomics.
P. polymyxa SC2 promotes growth of pepper stems and leaves in pot experiments in the greenhouse. Under interaction conditions, peppers stimulate the expression of genes related to quorum sensing, chemotaxis, and biofilm formation in P. polymyxa SC2. Peppers induced the expression of polymyxin and fusaricidin biosynthesis genes in P. polymyxa SC2, and these genes were up-regulated 2.93- to 6.13-fold and 2.77- to 7.88-fold, respectively. Under the stimulation of medium which has been used to culture pepper, the bacteriostatic diameter of P. polymyxa SC2 against Xanthomonas citri increased significantly. Concurrently, under the stimulation of P. polymyxa SC2, expression of transcription factor genes WRKY2 and WRKY40 in pepper was up-regulated 1.17-fold and 3.5-fold, respectively.
Through the interaction with pepper, the ability of P. polymyxa SC2 to inhibit pathogens was enhanced. P. polymyxa SC2 also induces systemic resistance in pepper by stimulating expression of corresponding transcription regulators. Furthermore, pepper has effects on chemotaxis and biofilm formation of P. polymyxa SC2. This study provides a basis for studying interactional mechanisms of P. polymyxa SC2 and pepper.
多粘类芽孢杆菌 SC2 是从辣椒根际土壤中分离得到的细菌，能促进辣椒的生长和生防。然而，其与辣椒的互作机制尚不清楚。本研究采用转录组学方法研究了多粘类芽孢杆菌 SC2 与辣椒的互作关系。
温室盆栽试验表明，多粘类芽孢杆菌 SC2 能促进辣椒茎和叶的生长。在互作条件下，辣椒诱导多粘类芽孢杆菌 SC2 中与群体感应、趋化和生物膜形成相关的基因表达。辣椒诱导多粘类芽孢杆菌 SC2 中多粘菌素和蕈蚊素生物合成基因的表达，分别上调 2.93-6.13 倍和 2.77-7.88 倍。在已培养辣椒的培养基的刺激下，多粘类芽孢杆菌 SC2 对柑橘溃疡病菌的抑菌直径显著增加。同时，在多粘类芽孢杆菌 SC2 的刺激下，转录因子基因 WRKY2 和 WRKY40 在辣椒中的表达分别上调 1.17 倍和 3.5 倍。
通过与辣椒的相互作用，多粘类芽孢杆菌 SC2 抑制病原菌的能力增强。多粘类芽孢杆菌 SC2 还通过刺激相应转录调控因子的表达诱导辣椒产生系统抗性。此外，辣椒对多粘类芽孢杆菌 SC2 的趋化作用和生物膜形成有影响。本研究为研究多粘类芽孢杆菌 SC2 与辣椒的互作机制提供了依据。
