植物根际促生枯草芽孢杆菌JC01筛选

Screening of plant growth-promoting Bacillus subtilis JC01 producing volatile organic compound

摘要:

【目的】筛选高效植物根际促生细菌，阐明产挥发性有机化合物(VOC)菌株JC01的促生机制。【方法】选取从植物根际中分离得到的838株细菌，以固氮、解(溶)磷以及分泌嗜铁素、吲哚乙酸(IAA)活性为指标，对其促生能力进行赋值评估，将赋值在3分以上的107株细菌进行指纹图谱分析，挑选其中不同簇的20株促生潜力细菌进行温室实验，以评价赋值体系与温室促生效果之间的关系，进一步探究具有较好促生效果菌株JC01的作用机理。【结果】共筛选出了来源于指纹图谱中不同簇的4株具有较好促生效果的菌株，细菌的平板活性赋值与促生效果之间的相关系数r大于0.6。其中，菌株JC01分泌的具有促生作用的VOC能够增强番茄植株IAA信号通路关键基因的表达，减弱脱落酸(ABA)、乙烯(ETH)信号通路关键基因的表达。JC01经16S rRNA基因鉴定为枯草芽孢杆菌。【结论】细菌的平板活性赋值与促生效果之间存在较高的正相关性，枯草芽孢杆菌JC01可能通过产生VOC对番茄生长进行调控。

Abstract:

[Objective] Among collected plant growth-promoting rhizobacteria (PGPR), we explored the plant growth-promoting mechanism of Bacillus subtilis JC01 producing volatile organic compound. [Methods] Among 838 bacterial strains isolated from rhizosphere soil, 107 strains were selected for amplified ribosomal DNA restriction analysis, according to their activities of nitrogen fixation, organic phosphorus decomposition, inorganic phosphorus solubilization, and indole-3-acetic acid (IAA) and siderophore production in vitro. A total of 20 potential bacteria from different clusters were assessed for the relationship between the assessment system and their plant growth promotion in greenhouse. The expression level of plant hormone signaling pathways related genes in tomato exposed to volatile organic compound (VOC) produced by JC01 was tested by real-time PCR. [Results] Four strains had high plant growth-promoting efficiency on different crops. Moreover, JC01 could produce VOC that efficiently promoted plant growth, and the emission upregulated the expression of IAA signaling pathway related gene, and downregulated that of abscisic acid (ABA) and ethylene (ETH) signaling pathways related genes. The 16S rRNA gene sequencing data defined that JC01 was Bacillus subtilis. [Conclusion] Bacillus subtilis JC01 promoted plant growth by producing VOC.