Abdallah Y, Yang M, Zhang M, Masum Md M I, Ogunyemi S O, Hossain A, An Q, Yan C, Li B
State Key laboratory of Rice Biology and Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou, China.
Department of Plant Pathology, Minia University, El-Minya, Egypt.
Lett Appl Microbiol. 2019 May;68(5):423-429. doi: 10.1111/lam.13117. Epub 2019 Feb 18.
The effects and mechanisms of Paenibacillus polymyxa Sx3 on growth promotion and the suppression of bacterial leaf blight in rice were evaluated in this study. The results from a plate assay indicated that Sx3 inhibited the growth of 20 strains of Xanthomonas oryzae pv. oryzae (Xoo). Rice seedling experiments indicated that Sx3 promoted plant growth and suppressed bacterial leaf blight. In addition, bacteriological tests showed that Sx3 was able to fix nitrogen, solubilize phosphate and produce indole acetic acid, indicating that various mechanisms may be involved in the growth promotion by Sx3. The culture filtrate of P. polymyxa Sx3 reduced bacterial growth, biofilm formation and disrupted the cell morphology of Xoo strain GZ 0005, as indicated by the transmission and scanning electron microscopic observations. In addition, MALDI-TOF MS analysis revealed that Sx3 could biosynthesize two types of secondary metabolites fusaricidins and polymyxin P. In summary, this study clearly indicated that P. polymyxa Sx3 has strong in vitro and in vivo antagonistic activity against Xoo, which may be at least partially attributed to its production of secondary metabolites. SIGNIFICANCE AND IMPACT OF THE STUDY: Antagonistic bacteria can grow well in their originating environment. However, it is unclear whether antagonistic bacteria were able to survive in different ecological environments. This study revealed that Paenibacillus polymyxa Sx3 isolated from rhizosphere soil of cotton significantly promoted the plant growth and suppressed bacterial leaf blight in rice. Therefore, it could be inferred that P. polymyxa Sx3 has the potential to be used as biocontrol agents in plants grown in different ecological environments.
本研究评估了多粘芽孢杆菌Sx3对水稻生长促进和细菌性条斑病抑制的影响及机制。平板试验结果表明，Sx3抑制了20株水稻白叶枯病菌（Xanthomonas oryzae pv. oryzae，Xoo）的生长。水稻幼苗试验表明，Sx3促进了植株生长并抑制了细菌性条斑病。此外，细菌学试验表明，Sx3能够固氮、解磷并产生吲哚乙酸，这表明Sx3促进生长可能涉及多种机制。多粘芽孢杆菌Sx3的培养滤液减少了Xoo菌株GZ 0005的细菌生长、生物膜形成并破坏了其细胞形态，透射电镜和扫描电镜观察结果表明了这一点。此外，基质辅助激光解吸电离飞行时间质谱分析显示，Sx3能够生物合成两种次生代谢产物镰刀菌素和多粘菌素P。总之，本研究明确表明，多粘芽孢杆菌Sx3对Xoo具有很强的体外和体内拮抗活性，这可能至少部分归因于其次生代谢产物的产生。研究的意义和影响：拮抗细菌在其原生环境中能够良好生长。然而，尚不清楚拮抗细菌是否能够在不同的生态环境中存活。本研究表明，从棉花根际土壤中分离得到的多粘芽孢杆菌Sx3显著促进了水稻的生长并抑制了细菌性条斑病。因此，可以推断多粘芽孢杆菌Sx3有潜力用作在不同生态环境中生长的植物的生物防治剂。
